| 3D Spider Mix Osteospermum | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Abelia 'Edward Goucher' | Direct sun (at least 4-6 hours) | Water weekly while establishing; mature plants are drought-tolerant and need water only in prolonged dry weather | Mildly toxic to pets |
| Abelia 'Kaleidoscope' | Direct sun (at least 4-6 hours) | Weekly during establishment, then only in extended drought | Mildly toxic to pets |
| Abelia 'Rose Creek' | Direct sun (at least 4-6 hours) | Weekly while establishing, then occasional deep watering in drought | Mildly toxic to pets |
| Abelia chinensis | Direct sun (at least 4-6 hours) | Weekly through the first season, then mainly during dry spells | Mildly toxic to pets |
| Abelia x grandiflora | Direct sun (at least 4-6 hours) | Weekly deep soak in the first season, then only during prolonged dry spells once established | Mildly toxic to pets |
| Abiqua Drinking Gourd Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Accent Scarlet Busy Lizzie | Medium indirect light (a couple of metres from a window) | Keep the compost evenly moist; typically water every 1-3 days in warm weather as plants wilt quickly in dry conditions | Mildly toxic to pets |
| Acer capillipes | Bright indirect light (just back from a sunny window) | Water deeply weekly while establishing; supplement in summer droughts | Pet-safe |
| Acer griseum | Direct sun (at least 4-6 hours) | Water deeply weekly while establishing; supplement in summer droughts | Pet-safe |
| Acer japonicum 'Aconitifolium' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply in dry spells | Pet-safe |
| Acer palmatum 'Atropurpureum' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply through dry weather | Pet-safe |
| Acer palmatum 'Butterfly' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist, more often in pots and heat | Pet-safe |
| Acer palmatum 'Dissectum' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist, more often in pots and heat | Pet-safe |
| Acer palmatum 'Garnet' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist, more often in pots and heat | Pet-safe |
| Acer palmatum 'Orangeola' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist, more often in containers and heat | Pet-safe |
| Acer rubrum | Direct sun (at least 4-6 hours) | Deep soak weekly for the first two seasons; established trees rely on rainfall | Mildly toxic to pets |
| Acer rubrum 'Autumn Blaze' | Direct sun (at least 4-6 hours) | Weekly while establishing; deep watering in droughts thereafter | Pet-safe |
| Acer rubrum 'October Glory' | Direct sun (at least 4-6 hours) | Weekly while establishing; deep watering in dry spells thereafter | Pet-safe |
| Achillea 'Terracotta' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; roughly every 7-10 days while establishing, rarely once mature | Toxic to pets |
| Achillea millefolium 'Cerise Queen' | Direct sun (at least 4-6 hours) | When the top few centimeters of soil are dry, about every 7-14 days | Mildly toxic to pets |
| Achillea ptarmica 'The Pearl' | Direct sun (at least 4-6 hours) | When the top few cm of soil dry out; roughly weekly, more in heat | Toxic to pets |
| Acorus gramineus | Bright indirect light (just back from a sunny window) | Keep soil constantly moist to wet; never allow to dry out | Mildly toxic to pets |
| Acorus gramineus 'Variegatus' | Bright indirect light (just back from a sunny window) | Keep soil constantly moist to wet at all times | Mildly toxic to pets |
| Adagio Maiden Grass | Direct sun (at least 4-6 hours) | Weekly in the first year, then mostly rainfall except in drought | Mildly toxic to pets |
| Adagio Maiden Grass | Direct sun (at least 4-6 hours) | Weekly for the first season; every 2–3 weeks once established | Pet-safe |
| Adiantum venustum | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil begins to dry, roughly every 4-6 days | Pet-safe |
| Adolphe Audusson Camellia | Bright indirect light (just back from a sunny window) | Every 5-7 days in the growing season; keep consistently moist but not waterlogged | Pet-safe |
| Adriatic Bellflower | Bright indirect light (just back from a sunny window) | Weekly during spring and summer; minimal in winter | Pet-safe |
| Adromischus Cristatus | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in growth | Mildly toxic to pets |
| Aechmea recurvata | Bright indirect light (just back from a sunny window) | Keep the small cup filled; refresh weekly and water mix when top few cm dry | Pet-safe |
| Aeonium 'Sunburst' | Bright indirect light (just back from a sunny window) | When the soil is dry in winter growth, sparingly during summer dormancy | Mildly toxic to pets |
| Aeonium Canariense | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is fully dry, roughly every 10-14 days in active growth | Mildly toxic to pets |
| Aeonium Castello-Paivae 'Variegata' | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in active growth | Mildly toxic to pets |
| Aeonium Decorum | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in active growth | Mildly toxic to pets |
| Aeonium Haworthii | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in active growth | Mildly toxic to pets |
| Aeonium Simsii | Bright indirect light (just back from a sunny window) | When the top few centimetres are dry, about every 7-12 days in active growth | Mildly toxic to pets |
| Aeonium Sunburst | Bright indirect light (just back from a sunny window) | When the top few centimetres of soil are dry, about weekly in active growth, sparingly in summer dormancy | Mildly toxic to pets |
| Aeonium Tabuliforme | Bright indirect light (just back from a sunny window) | When the soil is fully dry, about every 10-14 days in active growth | Mildly toxic to pets |
| Aeonium Velour | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is fully dry, roughly every 10-14 days in active growth | Mildly toxic to pets |
| Aesculifolia Rodgersia | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Aesculus × carnea 'Briotii' | Direct sun (at least 4-6 hours) | Water young trees weekly to establish, then rely on rainfall | Toxic to pets |
| Aesculus flava | Direct sun (at least 4-6 hours) | Deep watering every 7-10 days through the first two or three growing seasons; established trees rarely need irrigation | Toxic to pets |
| Aesculus hippocastanum | Direct sun (at least 4-6 hours) | Water young trees weekly to establish, then rely on rainfall | Toxic to pets |
| Afghan Iris | Direct sun (at least 4-6 hours) | Moderate in late winter to late spring; bone dry from midsummer to early autumn | Toxic to pets |
| African Chain Fern | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil feels barely moist, roughly every 5-8 days in growing season | Pet-safe |
| African Cornflag | Direct sun (at least 4-6 hours) | Weekly during the winter-spring growing season; none in summer dormancy | Mildly toxic to pets |
| African feather grass | Direct sun (at least 4-6 hours) | Every 1–2 weeks once established; more frequently when newly planted | Pet-safe |
| African Fern Pine | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days | Toxic to pets |
| African Kedrostis | Bright indirect light (just back from a sunny window) | Every 7–10 days in summer; once a month or less in winter | Mildly toxic to pets |
| African Tamarisk | Direct sun (at least 4-6 hours) | Low once established; moderate during establishment | Pet-safe |
| African Yellowwood | Bright indirect light (just back from a sunny window) | When the top few cm of soil dry, roughly weekly while establishing | Toxic to pets |
| Agapanthus africanus 'Albus' | Direct sun (at least 4-6 hours) | Water regularly, roughly twice weekly in hot weather while growing; keep just moist in winter | Mildly toxic to pets |
| Agastache 'Blue Fortune' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Agastache 'Kudos Coral' | Direct sun (at least 4-6 hours) | Water deeply during the first season while establishing, then only in prolonged drought once mature | Mildly toxic to pets |
| Agave americana | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave americana 'Marginata' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave americana 'Mediopicta Alba' | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave attenuata | Bright indirect light (just back from a sunny window) | When the top few centimetres of soil are dry, roughly every 1-2 weeks in summer | Mildly toxic to pets |
| Agave attenuata 'Boutin Blue' | Bright indirect light (just back from a sunny window) | When the top of the soil is dry, every 1-2 weeks in summer; sparingly in winter | Toxic to pets |
| Agave bracteosa | Bright indirect light (just back from a sunny window) | When the soil is dry, every 1-2 weeks in summer; sparingly in winter | Toxic to pets |
| Agave Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, roughly every 10-14 days in summer; very sparingly in winter | Pet-safe |
| Agave chrysantha | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth, only when soil is dry | Mildly toxic to pets |
| Agave deserti | Direct sun (at least 4-6 hours) | Every 3-4 weeks in growth, only when soil is bone dry | Mildly toxic to pets |
| Agave montana | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer; sparingly in winter | Mildly toxic to pets |
| Agave ovatifolia | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and rarely in winter | Mildly toxic to pets |
| Agave palmeri | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in the growing season, sparingly in winter | Mildly toxic to pets |
| Agave parrasana | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, monthly or less in winter | Mildly toxic to pets |
| Agave parryi | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave parryi 'Truncata' | Direct sun (at least 4-6 hours) | When fully dry, every 2-3 weeks in summer; monthly or less in winter | Toxic to pets |
| Agave parryi var. truncata | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave pelona | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, very sparingly in winter | Mildly toxic to pets |
| Agave schidigera | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, monthly or less in winter | Mildly toxic to pets |
| Agave shrevei | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, sparingly in winter | Mildly toxic to pets |
| Agave sobria | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, sparingly in winter | Mildly toxic to pets |
| Agave striata | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 2-3 weeks in summer, monthly or less in winter | Mildly toxic to pets |
| Agave toumeyana | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer; monthly or less in winter | Toxic to pets |
| Agave utahensis | Direct sun (at least 4-6 hours) | When fully dry, every 2-4 weeks in summer; little to none in winter | Toxic to pets |
| Agave victoriae-reginae | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in summer | Mildly toxic to pets |
| Agave victoriae-reginae 'Compacta' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and monthly or less in winter | Mildly toxic to pets |
| Agave vilmoriniana | Direct sun (at least 4-6 hours) | When the top of the soil is dry, every 1-2 weeks in summer; sparingly in winter | Toxic to pets |
| Agave xylonacantha | Direct sun (at least 4-6 hours) | When fully dry, every 2-3 weeks in summer; monthly or less in winter | Toxic to pets |
| Agave zebra | Direct sun (at least 4-6 hours) | When fully dry, every 2-4 weeks in summer; little to none in winter | Toxic to pets |
| Agnes Rose | Direct sun (at least 4-6 hours) | Deep watering once a week, more in drought or first season | Pet-safe |
| Aizoon Rosularia | Bright indirect light (just back from a sunny window) | Every 3–4 weeks in spring and summer; rarely in winter | Pet-safe |
| Akebia quinata | Bright indirect light (just back from a sunny window) | When the top 4-5 cm of soil dries, about every 7-10 days while establishing | Mildly toxic to pets |
| Akebia trifoliata | Bright indirect light (just back from a sunny window) | When the top 4-5 cm of soil dries, about every 7-10 days while establishing | Mildly toxic to pets |
| Alabama Lip Fern | Medium indirect light (a couple of metres from a window) | every 2-3 weeks | Mildly toxic to pets |
| Alan Fradd Rock Rose | Direct sun (at least 4-6 hours) | Establish with deep, infrequent waterings in the first season; drought-tolerant once established and needs no irrigation in typical UK summers. | Mildly toxic to pets |
| Alaska Mix Nasturtium | Direct sun (at least 4-6 hours) | When the top 3–5 cm of soil is dry, roughly every 7 days | Mildly toxic to pets |
| Albany Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks (allow full dry-down between waterings) | Toxic to pets |
| Albany Pitcher Plant | Bright indirect light (just back from a sunny window) | Keep substrate moist but not waterlogged; water when surface begins to lighten | Mildly toxic to pets |
| Albert's Gold tree heath | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks in summer once established | Pet-safe |
| Albion Black Pod nigella | Direct sun (at least 4-6 hours) | Weekly or as needed | Mildly toxic to pets |
| Albizia julibrissin | Direct sun (at least 4-6 hours) | Water weekly during establishment, then only in extended drought | Mildly toxic to pets |
| Albizia julibrissin 'Rosea' | Direct sun (at least 4-6 hours) | Water weekly while establishing, then only in prolonged drought | Mildly toxic to pets |
| Alchemilla mollis | Bright indirect light (just back from a sunny window) | Water in dry spells; established plants are drought-tolerant and need watering only occasionally | Mildly toxic to pets |
| Alerce | Bright indirect light (just back from a sunny window) | Keep consistently moist at all times; water deeply during any dry period and never allow drought | Mildly toxic to pets |
| Algerian Fir | Direct sun (at least 4-6 hours) | Low to moderate; highly drought-tolerant once established | Pet-safe |
| Alice's Sundew | Direct sun (at least 4-6 hours) | Keep soil constantly damp; tray topped up year-round, easing off slightly in winter | Mildly toxic to pets |
| Alisma plantago-aquatica | Direct sun (at least 4-6 hours) | Constantly wet; shallow margin | Mildly toxic to pets |
| all gold Japanese forest grass | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in dry or warm spells | Mildly toxic to pets |
| Allioni's Primrose | Bright indirect light (just back from a sunny window) | Moderately during spring and summer; very sparingly in winter | Toxic to pets |
| Allium 'Firmament' | Direct sun (at least 4-6 hours) | Water at planting and during spring growth; keep dry in summer dormancy | Toxic to pets |
| Allium 'Gladiator' | Direct sun (at least 4-6 hours) | Water during spring growth; keep dry in summer dormancy, every 2-3 weeks at most if drought-stressed | Toxic to pets |
| Allium 'Globemaster' | Direct sun (at least 4-6 hours) | Water during spring growth; keep dry through summer dormancy, every 2-3 weeks at most if drought-stressed | Toxic to pets |
| Allium 'Hair' | Direct sun (at least 4-6 hours) | Water at planting then only in prolonged spring drought; keep dry once dormant | Toxic to pets |
| Allium 'Mount Everest' | Direct sun (at least 4-6 hours) | Water in spring growth; keep dry over summer dormancy, every 2-3 weeks at most if very dry | Toxic to pets |
| Allium 'Purple Sensation' | Direct sun (at least 4-6 hours) | Water during active spring growth only; otherwise minimal, every 2-3 weeks if dry | Toxic to pets |
| Alma Potschke aster | Direct sun (at least 4-6 hours) | Weekly during the growing season; reduce after flowering | Pet-safe |
| Aloe 'Blue Elf' | Direct sun (at least 4-6 hours) | When the soil is dry, roughly every 1-2 weeks in summer and every 3-4 weeks in winter | Toxic to pets |
| Aloe 'Doran Black' | Bright indirect light (just back from a sunny window) | When the soil is dry, roughly every 1-2 weeks in summer and every 3-4 weeks in winter | Toxic to pets |
| Aloe 'Firebird' | Bright indirect light (just back from a sunny window) | When the soil is dry, roughly every 1-2 weeks in summer and every 3-4 weeks in winter | Toxic to pets |
| Aloe 'Hercules' | Direct sun (at least 4-6 hours) | When the soil is dry, roughly every 1-2 weeks in summer and every 3-4 weeks in winter | Toxic to pets |
| Aloe Aculeata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | Toxic to pets |
| Aloe Burgersfortensis | Direct sun (at least 4-6 hours) | When the mix has dried out, roughly every 2 weeks in summer | Toxic to pets |
| Aloe Comosa | Direct sun (at least 4-6 hours) | Only when bone dry, roughly every 3 weeks in active growth | Toxic to pets |
| Aloe Dorotheae | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in growth | Toxic to pets |
| Aloe Erinacea | Direct sun (at least 4-6 hours) | When the soil is bone dry, every 2-3 weeks at most in growth | Toxic to pets |
| Aloe Ferox | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | Toxic to pets |
| Aloe Gariepensis | Direct sun (at least 4-6 hours) | Only when completely dry, roughly every 2-3 weeks in growth | Toxic to pets |
| Aloe Globuligemma | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer | Toxic to pets |
| Aloe Greatheadii | Direct sun (at least 4-6 hours) | When the mix is dry, roughly every 2 weeks in summer | Toxic to pets |
| Aloe Krapohliana | Direct sun (at least 4-6 hours) | Sparingly when soil is fully dry — roughly every 2-3 weeks in active growth, very little in summer dormancy | Toxic to pets |
| Aloe Linearifolia | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out — roughly every 1-2 weeks in summer, less in winter | Toxic to pets |
| Aloe Rauhii | Bright indirect light (just back from a sunny window) | When soil is dry, roughly every 2 weeks in growth | Toxic to pets |
| Aloe Reitzii | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and once a month or less in winter | Toxic to pets |
| Aloe Rubroviolacea | Direct sun (at least 4-6 hours) | When the soil is completely dry, about every 2-3 weeks in summer and monthly or less in winter | Toxic to pets |
| Aloe Secundiflora | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in summer and once a month in winter | Toxic to pets |
| Aloe Speciosa | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and monthly or less in winter | Toxic to pets |
| Aloe Thraskii | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in summer and monthly in winter | Toxic to pets |
| Aloe Tomentosa | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and monthly or less in winter | Toxic to pets |
| Aloe Vanbalenii | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in summer and monthly in winter | Toxic to pets |
| Aloe Wickensii | Direct sun (at least 4-6 hours) | When the soil is completely dry, about every 2-3 weeks in the growing season | Toxic to pets |
| Aloe-like Nananthus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer; once every 4-6 weeks in winter | Mildly toxic to pets |
| Aloinopsis luckhoffii | Direct sun (at least 4-6 hours) | During cool-season growth (autumn-spring); keep nearly dry in summer | Mildly toxic to pets |
| Aloinopsis malherbei | Direct sun (at least 4-6 hours) | Mainly autumn through spring; keep nearly dry in summer dormancy | Mildly toxic to pets |
| Aloinopsis rosulata | Direct sun (at least 4-6 hours) | Autumn through spring growth; keep nearly dry in summer | Mildly toxic to pets |
| Aloinopsis schooneesii | Direct sun (at least 4-6 hours) | Autumn through spring; reduce sharply in summer and keep dry in deep winter cold | Mildly toxic to pets |
| Aloinopsis setifera | Direct sun (at least 4-6 hours) | Autumn through spring growth; keep nearly dry in summer | Mildly toxic to pets |
| Alonso's Turbinicarpus | Direct sun (at least 4-6 hours) | When the soil is bone dry, roughly every 14-21 days in the growing season; withhold almost entirely in winter | Pet-safe |
| Alphonse Karr Bamboo | Direct sun (at least 4-6 hours) | Regularly during summer, approximately every 5–7 days; reduce in cooler months as growth slows | Pet-safe |
| Alpine Balsam | Direct sun (at least 4-6 hours) | Every 7–14 days during growth; reduce after setting seed | Mildly toxic to pets |
| Alpine Bartsia | Bright indirect light (just back from a sunny window) | Keep evenly moist; water regularly to prevent drying out | Mildly toxic to pets |
| Alpine bearberry | Direct sun (at least 4-6 hours) | Moderate; keep soil moist but well-drained; water regularly during dry periods | Pet-safe |
| Alpine Butterwort | Bright indirect light (just back from a sunny window) | Keep the medium constantly damp in growth via a shallow tray; reduce sharply when the winter resting bud forms | Mildly toxic to pets |
| Alpine Cinquefoil | Direct sun (at least 4-6 hours) | Every 10–14 days; very drought-tolerant once established | Pet-safe |
| Alpine Clematis | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days in the growing season | Toxic to pets |
| Alpine Heron's Bill | Direct sun (at least 4-6 hours) | Low to moderate — allow soil surface to dry between waterings | Mildly toxic to pets |
| Alpine Lady Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week; more frequently in warm weather | Pet-safe |
| Alpine Liverwort | Bright indirect light (just back from a sunny window) | Low to moderate — water when the top centimetre of soil dries | Mildly toxic to pets |
| Alpine Mouse-ear | Direct sun (at least 4-6 hours) | Sparingly — allow soil to dry between waterings; minimal winter moisture | Pet-safe |
| Alpine Pink | Direct sun (at least 4-6 hours) | Low to moderate; water when the top 2 cm of soil are dry | Mildly toxic to pets |
| Alpine Rock Cress | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Alpine Rock Jasmine | Direct sun (at least 4-6 hours) | Low — allow the top inch of soil to dry between waterings | Mildly toxic to pets |
| Alpine Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks when in growth (spring–summer); very sparingly in winter | Pet-safe |
| Alpine Sea Holly | Direct sun (at least 4-6 hours) | Water during establishment and in extended dry spells; otherwise infrequently | Mildly toxic to pets |
| Alpine Squill | Medium indirect light (a couple of metres from a window) | Water during growth; dry during summer dormancy | Toxic to pets |
| Alpine Toadflax | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; minimal in winter. | Mildly toxic to pets |
| Alpine Totara | Direct sun (at least 4-6 hours) | When the top few cm of soil dry out, roughly weekly while establishing | Toxic to pets |
| Alpine Water Fern | Medium indirect light (a couple of metres from a window) | When the top 1 cm of soil feels dry, roughly every 4-6 days in summer | Pet-safe |
| Alpine Woodsia | Medium indirect light (a couple of metres from a window) | every 1-2 weeks during the growing season | Mildly toxic to pets |
| Altissimo Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the first season; established plants when the top 5 cm of soil is dry | Pet-safe |
| Amazon Mist Sedge | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply once or twice weekly in heat, less in cool weather | Mildly toxic to pets |
| Amelanchier × grandiflora 'Robin Hill' | Direct sun (at least 4-6 hours) | Weekly deep watering through the first two seasons; established trees need water only in prolonged drought | Mildly toxic to pets |
| Amelanchier canadensis | Direct sun (at least 4-6 hours) | Weekly while establishing; prefers consistently moist soil | Mildly toxic to pets |
| America Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while establishing; mature plants when the top few centimetres of soil dry out | Pet-safe |
| American Beachgrass | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| American Climbing Fern | Medium indirect light (a couple of metres from a window) | Keep the soil consistently and evenly moist — never allow it to dry out between waterings | Mildly toxic to pets |
| American Dunegrass | Direct sun (at least 4-6 hours) | Low; drought-tolerant | Pet-safe |
| American Elm Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil begins to dry, frequently in summer | Mildly toxic to pets |
| American Holly | Bright indirect light (just back from a sunny window) | Weekly while establishing, then during dry spells | Toxic to pets |
| American Hornbeam | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil approaches dryness, often daily in summer | Mildly toxic to pets |
| American Lady Fern | Low light (north window or shaded room) | Every 2–3 days during active growth; less frequently in winter | Pet-safe |
| American Parsley Fern | Bright indirect light (just back from a sunny window) | Keep consistently moist; never allow to fully dry out | Mildly toxic to pets |
| American Royal Fern | Medium indirect light (a couple of metres from a window) | Twice weekly or more; keep consistently moist | Pet-safe |
| American Wall Fern | Medium indirect light (a couple of metres from a window) | Every 7–10 days when in growth; every 2–3 weeks in winter | Pet-safe |
| American White Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic — crown submerged 15–60 cm (6–24 in) below water surface | Pet-safe |
| American wisteria | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once mature | Toxic to pets |
| American Wood Anemone | Medium indirect light (a couple of metres from a window) | Weekly during active spring growth; none during summer dormancy | Toxic to pets |
| Anaga Monanthes | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; every 4–6 weeks in winter | Mildly toxic to pets |
| Andean Silver-Leaf Sage | Direct sun (at least 4-6 hours) | Allow soil to dry 2–3 cm between waterings | Mildly toxic to pets |
| Anderson's Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Anderson's Holly Fern | Medium indirect light (a couple of metres from a window) | Twice weekly in the growing season, weekly in winter | Pet-safe |
| Andorra Compact Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days in the first season, then sparingly | Mildly toxic to pets |
| Anemone × hybrida 'Honorine Jobert' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply weekly in dry spells, more in its first year | Toxic to pets |
| Anemone × hybrida 'Königin Charlotte' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply once a week in dry weather, more while establishing | Toxic to pets |
| Anemone × hybrida 'Pamina' | Bright indirect light (just back from a sunny window) | Keep evenly moist; deep weekly watering in dry weather, more while establishing | Toxic to pets |
| Anemone × hybrida 'September Charm' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry; keep evenly moist, especially while establishing | Toxic to pets |
| Anemone coronaria 'Hollandia' | Direct sun (at least 4-6 hours) | Keep soil evenly moist during active growth and flowering; every 5-7 days if no rain | Toxic to pets |
| Anemone coronaria 'Meron Violet' | Direct sun (at least 4-6 hours) | Keep soil evenly moist during active growth and flowering; reduce as foliage yellows toward dormancy | Toxic to pets |
| Anemone coronaria 'Mr. Fokker' | Direct sun (at least 4-6 hours) | Keep soil evenly moist through growth and flowering; reduce as foliage yellows toward dormancy | Toxic to pets |
| Anemone coronaria 'The Bride' | Direct sun (at least 4-6 hours) | Keep soil evenly moist through growth and flowering; reduce as foliage yellows toward dormancy | Toxic to pets |
| Anemone hupehensis 'Hadspen Abundance' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply weekly in dry spells and more during establishment | Toxic to pets |
| Angel Frost Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in hot weather; every 2–3 days in spring and autumn | Pet-safe |
| Angel's Fishing Rod | Direct sun (at least 4-6 hours) | Regular during spring and summer; reduced in winter | Mildly toxic to pets |
| Angel's Tears Daffodil | Direct sun (at least 4-6 hours) | Low; water during active growth, dry summer dormancy | Toxic to pets |
| Angel's Tears Daffodil | Direct sun (at least 4-6 hours) | Once per week during active spring growth; dry dormancy required in summer | Toxic to pets |
| Angel's Trumpet Hybrid | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (keep consistently moist) | Toxic to pets |
| Angelina Stonecrop | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in summer; little to none in winter | Pet-safe |
| Angelique Double Tulip | Direct sun (at least 4-6 hours) | Water at planting; minimal supplemental irrigation during growth; dry during dormancy | Toxic to pets |
| Anguloa clowesii | Bright indirect light (just back from a sunny window) | Every 5-7 days in active summer growth; taper to roughly every 2-3 weeks once leaves yellow and drop | Mildly toxic to pets |
| Anise-scented Sage | Bright indirect light (just back from a sunny window) | Regular throughout the growing season | Pet-safe |
| Annual baby's breath | Direct sun (at least 4-6 hours) | Once weekly; allow the soil to dry slightly between waterings | Mildly toxic to pets |
| Annual Phlox 'Sugar Stars' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 4-7 days | Pet-safe |
| Antimima dualis | Direct sun (at least 4-6 hours) | Thorough but infrequent autumn-spring; little or none in summer | Mildly toxic to pets |
| Antirrhinum majus 'Chantilly Bronze' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Antirrhinum majus 'Rocket Red' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Antirrhinum majus 'Sonnet Pink' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Antirrhinum majus 'Twinny Peach' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | Pet-safe |
| Apache beggarticks | Direct sun (at least 4-6 hours) | Every 3–5 days in containers; every 7–10 days in-ground once established | Mildly toxic to pets |
| Apennine Windflower | Medium indirect light (a couple of metres from a window) | Rainfall usually sufficient in woodland settings; water once per week only during dry springs | Toxic to pets |
| Aponogeton distachyos | Direct sun (at least 4-6 hours) | Permanently submerged; maintain a stable pond water level | Mildly toxic to pets |
| Apple Blossom flowering quince | Bright indirect light (just back from a sunny window) | Weekly when establishing; rainfall sufficient for established plants in temperate climates | Mildly toxic to pets |
| Aptos Blue Redwood | Direct sun (at least 4-6 hours) | Weekly when young; every 1–2 weeks when established | Pet-safe |
| Aptos Blue Redwood | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days in summer | Mildly toxic to pets |
| Arborvitae | Direct sun (at least 4-6 hours) | Deeply once or twice a week for the first 1-2 growing seasons, then mainly in droughts | Toxic to pets |
| Argyroderma delaetii | Direct sun (at least 4-6 hours) | During autumn-to-spring growth let the gritty mix dry fully between soaks; keep dry in summer dormancy | Mildly toxic to pets |
| Argyroderma fissum | Direct sun (at least 4-6 hours) | Let the gritty mix dry fully between soaks in autumn-to-spring growth; keep dry in summer | Mildly toxic to pets |
| Argyroderma pearsonii | Direct sun (at least 4-6 hours) | Let the gritty mix dry fully between soaks in autumn-to-spring growth; keep dry in summer | Mildly toxic to pets |
| Argyroderma testiculare | Direct sun (at least 4-6 hours) | Only during active growth (autumn through spring); keep bone-dry in summer dormancy | Mildly toxic to pets |
| Arid Mountain Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the cool growing season (autumn–spring); none in summer | Toxic to pets |
| Arisaema consanguineum | Medium indirect light (a couple of metres from a window) | Keep evenly moist during growth, about every 4-7 days; ease off as it dies back | Toxic to pets |
| Arisaema elephas | Medium indirect light (a couple of metres from a window) | Keep evenly moist during growth, about every 4-7 days; reduce as it dies back | Toxic to pets |
| Arisaema griffithii | Medium indirect light (a couple of metres from a window) | Keep evenly moist through growth, roughly every 4-7 days; reduce sharply once foliage yellows | Toxic to pets |
| Arisaema jacquemontii | Bright indirect light (just back from a sunny window) | Keep evenly moist in spring and summer growth; allow to dry as the leaf dies back in late summer | Toxic to pets |
| Arisaema nepenthoides | Bright indirect light (just back from a sunny window) | Keep evenly moist in spring and summer; let it dry as the leaf dies back in late summer | Toxic to pets |
| Arisaema ringens | Medium indirect light (a couple of metres from a window) | Keep evenly moist during growth, about every 4-7 days; reduce as it dies back | Toxic to pets |
| Arisaema serratum | Bright indirect light (just back from a sunny window) | Keep evenly moist through spring and summer; allow drying as the leaf dies back in autumn | Toxic to pets |
| Arisaema speciosum | Medium indirect light (a couple of metres from a window) | Keep evenly moist through growth, about every 4-7 days; reduce as it dies back | Toxic to pets |
| Arisaema tortuosum | Medium indirect light (a couple of metres from a window) | Keep moist through the growing season, about every 4-7 days; reduce as it dies back | Toxic to pets |
| Arizona Chalk Dudleya | Direct sun (at least 4-6 hours) | Every 3–4 weeks in winter and early spring; completely dry in summer dormancy | Mildly toxic to pets |
| Arizona Cypress | Direct sun (at least 4-6 hours) | Every 1-2 weeks while establishing, then rarely | Mildly toxic to pets |
| Arizona Cypress 'Blue Ice' | Direct sun (at least 4-6 hours) | Every 1-2 weeks while establishing, then rarely | Mildly toxic to pets |
| Arkansas Beardtongue | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Armand's Clematis | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days | Toxic to pets |
| Armenian Speedwell | Direct sun (at least 4-6 hours) | Every 10–14 days during the growing season; little to none in winter. | Pet-safe |
| Armored Frailea | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Aroanian Germander | Direct sun (at least 4-6 hours) | Minimal — once every 3 weeks in summer; dry in winter | Mildly toxic to pets |
| Aromatic Aster | Direct sun (at least 4-6 hours) | Water to establish, then rarely; very drought-tolerant | Pet-safe |
| Aromatic Aster 'Raydon's Favorite' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days once established | Mildly toxic to pets |
| Arrowwood Viburnum | Direct sun (at least 4-6 hours) | Weekly when young; established plants tolerate both moist and occasionally dry soil | Pet-safe |
| Arum italicum | Medium indirect light (a couple of metres from a window) | Keep evenly moist in active growth (autumn to spring); reduce sharply during summer dormancy | Toxic to pets |
| Ashton's Ice Plant | Direct sun (at least 4-6 hours) | When the top 2–3 cm of soil is dry, roughly every 7–14 days during the growing season; minimal in winter | Mildly toxic to pets |
| Ashy Broom | Direct sun (at least 4-6 hours) | Low — water sparingly once established | Toxic to pets |
| Asian Star Jasmine | Medium indirect light (a couple of metres from a window) | Water every 7-10 days during the first growing season; established plants are fairly drought-tolerant and need watering only during prolonged dry periods | Mildly toxic to pets |
| Asian Wonder Bamboo | Medium indirect light (a couple of metres from a window) | 2-3 times per week during active growth; once per week in cool or dormant periods | Pet-safe |
| Asphodel Cranesbill | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce in autumn | Pet-safe |
| Asplenium platyneuron | Low light (north window or shaded room) | Water when the top 2-3 cm is dry; tolerates short dry spells better than most ferns | Pet-safe |
| Aster 'Alma Potschke' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Aster 'Fellowship' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7 days | Mildly toxic to pets |
| Aster 'Harrington's Pink' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Aster 'Hella Lacy' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Aster 'Little Carlow' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Aster 'Monte Cassino' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during summer | Mildly toxic to pets |
| Aster 'Professor Kippenburg' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days in summer | Mildly toxic to pets |
| Aster 'Purple Dome' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Aster 'Vibrant Dome' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Aster 'Wood's Pink' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7 days | Mildly toxic to pets |
| Aster × frikartii 'Mönch' | Direct sun (at least 4-6 hours) | Water to establish, then moderately; water in prolonged dry spells | Pet-safe |
| Astilbe 'Bridal Veil' | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Astilbe 'Deutschland' | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water every 3-5 days or as needed to prevent the top 2 cm of soil drying out | Pet-safe |
| Astilbe 'Fanal' | Bright indirect light (just back from a sunny window) | Keep soil constantly moist; water every 2-4 days in summer, never letting it dry out | Mildly toxic to pets |
| Astilbe 'Fanal' | Medium indirect light (a couple of metres from a window) | Consistently moist — water whenever the top 2-3 cm of soil begins to dry, roughly every 3-5 days in summer | Pet-safe |
| Astilbe chinensis 'Pumila' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil begins to dry; keep evenly moist, often 2-3 times weekly in heat | Mildly toxic to pets |
| Astilbe simplicifolia 'Sprite' | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Astroloba Bullulata | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in growth; monthly or less in winter | Mildly toxic to pets |
| Astroloba Congesta | Bright indirect light (just back from a sunny window) | When soil is completely dry, about every 2-3 weeks in growth and monthly or less in winter | Mildly toxic to pets |
| Athyrium angustum f. rubellum 'Lady in Red' | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist, watering when the top 2-3 cm dries, roughly every 4-6 days | Mildly toxic to pets |
| Athyrium filix-femina 'Frizelliae' | Low light (north window or shaded room) | Keep evenly moist; water every 4-6 days, more in hot weather | Mildly toxic to pets |
| Athyrium filix-femina 'Minutissimum' | Low light (north window or shaded room) | Keep consistently moist; water every 4-6 days, more in heat | Mildly toxic to pets |
| Athyrium niponicum 'Red Beauty' | Low light (north window or shaded room) | Keep evenly moist; water every 4-6 days, more often in heat | Mildly toxic to pets |
| Athyrium niponicum 'Ursula's Red' | Low light (north window or shaded room) | Keep evenly moist; water every 4-6 days, increasing in hot weather | Mildly toxic to pets |
| Athyrium otophorum | Low light (north window or shaded room) | Keep evenly moist; water every 4-6 days, more in heat | Mildly toxic to pets |
| Atlantic Monanthes | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring and summer; once monthly in winter | Mildly toxic to pets |
| Atlantic Wild Indigo | Direct sun (at least 4-6 hours) | Low once established; water weekly in the first season | Toxic to pets |
| Atlas Cedar | Direct sun (at least 4-6 hours) | Weekly during establishment; very drought-tolerant once established | Mildly toxic to pets |
| Atlas Poppy | Direct sun (at least 4-6 hours) | Once a week in dry spells during active growth; largely drought-tolerant once established | Toxic to pets |
| Aucuba japonica Crotonifolia | Low light (north window or shaded room) | Water to establish, then every 7-14 days in dry spells; less in cool months | Mildly toxic to pets |
| Aucuba japonica Picturata | Low light (north window or shaded room) | When the top 3-5 cm of soil is dry, about weekly while establishing then less often | Mildly toxic to pets |
| Aucuba japonica Rozannie | Low light (north window or shaded room) | When the top 3-5 cm of soil is dry, roughly weekly in the first year then far less once established | Mildly toxic to pets |
| Augustine's rhododendron | Bright indirect light (just back from a sunny window) | Every 7–10 days in active growth; reduce in winter | Toxic to pets |
| Aunt Eliza Montbretia | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season; allow to dry back naturally in autumn | Mildly toxic to pets |
| Aureola Japanese Forest Grass | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil feels dry, roughly every 5-7 days in the growing season | Pet-safe |
| Auricula | Bright indirect light (just back from a sunny window) | Moderately in spring and summer; reduce significantly in autumn and winter | Toxic to pets |
| Auricula Primrose | Bright indirect light (just back from a sunny window) | Water when top 2 cm of soil is dry; more frequent in active growth, sparingly in summer | Mildly toxic to pets |
| Austral Bracken | Direct sun (at least 4-6 hours) | Once established, largely drought-tolerant; water deeply once a week in dry spells | Toxic to pets |
| Australian Bangalow Palm | Direct sun (at least 4-6 hours) | Weekly during establishment; every 10–14 days once established in-ground | Pet-safe |
| Australian Cabbage Palm | Bright indirect light (just back from a sunny window) | Every 5–7 days in summer, fortnightly in winter | Mildly toxic to pets |
| Australian Cabbage Palm | Direct sun (at least 4-6 hours) | Water when the top 4-5 cm of soil dries out, roughly every 10-14 days in active growth | Pet-safe |
| Australian Cycad | Bright indirect light (just back from a sunny window) | Every 14–21 days in summer; very sparingly in winter | Toxic to pets |
| Australian Tree Fern | Bright indirect light (just back from a sunny window) | 2-3 times per week; increase in heat and wind | Pet-safe |
| Autumn Arum | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil is dry during autumn-winter growing season; minimal in summer dormancy | Toxic to pets |
| Autumn Cascades Tupelo | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Autumn Crocus | Direct sun (at least 4-6 hours) | Low — naturally rainfall-dependent; needs dry summer dormancy | Mildly toxic to pets |
| Autumn Crocus | Bright indirect light (just back from a sunny window) | Relies on natural rainfall; rarely needs supplementary watering | Toxic to pets |
| Autumn Crocus Speciosus | Direct sun (at least 4-6 hours) | Rainfall usually sufficient outdoors; water sparingly once per week only if autumn is exceptionally dry | Mildly toxic to pets |
| Autumn Daffodil | Direct sun (at least 4-6 hours) | Moderate during autumn and spring growth; dry during summer dormancy | Toxic to pets |
| Autumn Fern 'Brilliance' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil is dry, roughly every 4-7 days | Mildly toxic to pets |
| Autumn Gentian | Direct sun (at least 4-6 hours) | Very low — rain-fed only | Mildly toxic to pets |
| Autumn Gold Maidenhair Tree | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days when young | Toxic to pets |
| Autumn heath | Direct sun (at least 4-6 hours) | Fortnightly during establishment; drought-tolerant once established | Pet-safe |
| Autumn Joy Stonecrop | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought — roughly every 10-14 days if newly planted | Mildly toxic to pets |
| Autumn Laelia | Bright indirect light (just back from a sunny window) | Every 5–7 days in spring and early summer; taper to every 2–3 weeks in late summer | Pet-safe |
| Autumn Moor Grass | Direct sun (at least 4-6 hours) | Weekly during the first season; established plants only in prolonged drought | Mildly toxic to pets |
| Autumn Moor Grass | Medium indirect light (a couple of metres from a window) | Every 10-14 days during establishment; drought-tolerant once established | Pet-safe |
| Autumn Pineapple Lily | Direct sun (at least 4-6 hours) | Moderate during growth; reduce after foliage dies back | Toxic to pets |
| Autumn Pineapple Lily | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days during the growing season | Toxic to pets |
| Autumn Sage | Direct sun (at least 4-6 hours) | Occasional once established; regular for first season | Pet-safe |
| Autumn Squill | Direct sun (at least 4-6 hours) | Very sparingly; allow soil to dry completely between waterings, roughly every 14-21 days in active season | Toxic to pets |
| Avalanche Feather Reed Grass | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, around weekly; tolerant of occasional wet ground | Pet-safe |
| Avalanche Reed Grass | Bright indirect light (just back from a sunny window) | Every 7-14 days; keep moderately moist in the growing season | Pet-safe |
| Azalea 'Firefly' | Bright indirect light (just back from a sunny window) | When the top 3 cm of soil is dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Azalea 'Gibraltar' | Bright indirect light (just back from a sunny window) | Deeply once or twice a week in dry weather; keep consistently moist year-round | Toxic to pets |
| Azalea 'Hino-Crimson' | Bright indirect light (just back from a sunny window) | Deeply once a week; increase in hot, dry spells | Toxic to pets |
| Azalea 'Weston's Flamingo' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil feels dry, roughly every 5-7 days in summer; reduce in winter | Toxic to pets |
| Azolla filiculoides | Direct sun (at least 4-6 hours) | Floats permanently on still water; no separate watering | Mildly toxic to pets |
| Azores Jasmine | Direct sun (at least 4-6 hours) | Every 5–7 days in summer; every 10–14 days in winter | Pet-safe |
| Aztec Cactus | Bright indirect light (just back from a sunny window) | When the potting mix is almost completely dry, roughly every 14-28 days in the growing season; very sparingly in winter | Pet-safe |
| Aztec Lily | Direct sun (at least 4-6 hours) | Regular watering while in active growth; keep dry during autumn–winter dormancy | Toxic to pets |
| Azure Grape Hyacinth | Direct sun (at least 4-6 hours) | Water during active growth; allow to dry out completely in summer | Mildly toxic to pets |
| Baby Love Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season, more in heat or in pots | Pet-safe |
| Baby Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Pet-safe |
| Baby Tears Plant | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist, watering every 3-5 days | Pet-safe |
| Baby Toes | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer active season; very rarely in winter | Pet-safe |
| Baby's breath | Direct sun (at least 4-6 hours) | Every 10–14 days when established; weekly when young | Mildly toxic to pets |
| Bachelor's button | Direct sun (at least 4-6 hours) | Every 7–10 days | Pet-safe |
| Bacopa | Bright indirect light (just back from a sunny window) | Every 2–3 days in containers during warm weather; reduce in cooler conditions | Pet-safe |
| Bacopa 'Scopia Gulliver Purple' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost starts to dry, often daily in warm weather | Pet-safe |
| Bacopa 'Snowtopia' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost begins to dry, often daily in warm weather | Pet-safe |
| Bahian Neoregelia | Direct sun (at least 4-6 hours) | Water sparingly; allow potting medium to dry between waterings and keep a small amount of water in the central cup | Pet-safe |
| Bailey Palm | Direct sun (at least 4-6 hours) | When the top 6-10 cm of soil is dry, roughly every 10-14 days in the growing season; every 4-6 weeks in winter | Pet-safe |
| Baines' Cyphostemma | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; once a month or less in winter | Toxic to pets |
| Bald Cypress | Direct sun (at least 4-6 hours) | Daily in summer; can stand in a water tray during heat | Mildly toxic to pets |
| Bald Cypress Bonsai 'Cascade' | Direct sun (at least 4-6 hours) | Keep consistently moist; in summer often daily, and it can stand in a shallow water tray | Mildly toxic to pets |
| Balkan Pink | Direct sun (at least 4-6 hours) | Low; water sparingly, allowing soil to dry fully between waterings | Mildly toxic to pets |
| Balkan Rock Pink | Direct sun (at least 4-6 hours) | Very infrequent; drought-tolerant | Mildly toxic to pets |
| Balkan Sage | Medium indirect light (a couple of metres from a window) | Weekly during dry spells | Pet-safe |
| Ball Moss | Medium indirect light (a couple of metres from a window) | Mist or briefly submerge 2–3 times a week in summer; 1–2 times a week in winter | Pet-safe |
| Ballerina Rose | Direct sun (at least 4-6 hours) | Deep watering once or twice weekly | Pet-safe |
| Balsam Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; naturally rainfall-sustained thereafter | Pet-safe |
| Balsam Gourd | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; monthly or less in winter | Mildly toxic to pets |
| Banana Passion Fruit | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-6 days in active growth | Mildly toxic to pets |
| Banana passionflower | Bright indirect light (just back from a sunny window) | Weekly in growing season, reduce in winter | Mildly toxic to pets |
| Banana passionfruit | Bright indirect light (just back from a sunny window) | Every 7–10 days; keep evenly moist | Mildly toxic to pets |
| Baptisia 'Purple Smoke' | Direct sun (at least 4-6 hours) | Weekly the first season; minimal once established | Toxic to pets |
| Barbara Karst Bougainvillea | Direct sun (at least 4-6 hours) | Deeply every 7–10 days when established; more often for container plants | Mildly toxic to pets |
| Barla's Masdevallia | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; roots should never dry out completely | Pet-safe |
| Barrelier's Sage | Direct sun (at least 4-6 hours) | Weekly to establish, then fortnightly | Pet-safe |
| Bartram's Air Plant | Bright indirect light (just back from a sunny window) | Mist lightly 3–4 times a week or soak briefly once a week | Pet-safe |
| Basil-Leaved Sun Rose | Direct sun (at least 4-6 hours) | Very low — minimal supplemental irrigation needed once established | Mildly toxic to pets |
| Basketgrass | Bright indirect light (just back from a sunny window) | Every 5–7 days in growing season; every 10–14 days in winter | Pet-safe |
| Bastard Cobas | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once every 4–6 weeks or less in winter | Toxic to pets |
| Bear Tupelo | Bright indirect light (just back from a sunny window) | Regularly; keep consistently moist | Pet-safe |
| Bearberry Cotoneaster | Direct sun (at least 4-6 hours) | Fortnightly once established; more frequent for the first growing season | Mildly toxic to pets |
| Bearded Huernia | Bright indirect light (just back from a sunny window) | Every 14–21 days when actively growing (spring–autumn); minimal in winter (once a month or less) | Pet-safe |
| Bearded Trichodiadema | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in the growing season (winter-spring); reduce in summer when the plant is semi-dormant | Pet-safe |
| Beardtongue 'Husker Red' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days during the growing season | Mildly toxic to pets |
| Beaugleholes Bladderwort | Bright indirect light (just back from a sunny window) | Keep substrate constantly moist year-round | Mildly toxic to pets |
| beautiful feather grass | Direct sun (at least 4-6 hours) | Weekly in the first season; minimal once established | Pet-safe |
| Beautiful Fuchsia | Bright indirect light (just back from a sunny window) | Water freely in growth; reduce in winter | Pet-safe |
| Beautiful Graptopetalum | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; monthly or less in winter | Pet-safe |
| Beautiful Living Stones | Direct sun (at least 4-6 hours) | Seasonally — water only during active growth (late summer through autumn and again briefly in spring); keep dry the rest of the year | Pet-safe |
| Becky Shasta daisy | Direct sun (at least 4-6 hours) | Every 5–7 days in the growing season; less in cool or wet weather | Mildly toxic to pets |
| Bee Balm 'Cambridge Scarlet' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Pet-safe |
| Bee Orchid | Bright indirect light (just back from a sunny window) | Low; drought-tolerant once established | Pet-safe |
| Belize Sage | Bright indirect light (just back from a sunny window) | Twice weekly during active growth | Pet-safe |
| Bell Cotyledon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; every 5–6 weeks in winter | Toxic to pets |
| Belladonna larkspur | Direct sun (at least 4-6 hours) | Regular — deep water 2–3 times per week during growth; ease off in wet periods | Toxic to pets |
| Belladonna Lily | Direct sun (at least 4-6 hours) | Minimal or none in summer dormancy; regular from flower emergence through winter while foliage is active; reduce in late spring | Toxic to pets |
| Belle Etoile Mock Orange | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days | Mildly toxic to pets |
| Bellflower Codonopsis | Medium indirect light (a couple of metres from a window) | Water when the top 2–3 cm of soil is dry during the growing season; reduce significantly in winter | Mildly toxic to pets |
| Beni-kaze Hakone Grass | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Bent Enkianthus | Bright indirect light (just back from a sunny window) | Regular — keep consistently moist | Toxic to pets |
| Bent Masdevallia | Bright indirect light (just back from a sunny window) | Every 2-3 days in warm weather, every 3-4 days in winter | Pet-safe |
| Bent Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist through spring; tolerates slightly drier conditions during summer dormancy | Mildly toxic to pets |
| Bergeranthus multiceps | Direct sun (at least 4-6 hours) | When the top of the soil is dry, roughly every 7-10 days in active growth; reduce in peak summer and winter | Mildly toxic to pets |
| Berlandier's Jatropha | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly or less in winter | Toxic to pets |
| Berry Smoothie Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly | Pet-safe |
| Besom heath | Direct sun (at least 4-6 hours) | Weekly during establishment; largely self-sufficient once established | Pet-safe |
| Bethencourt's Aichryson | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season (spring and autumn); sparingly in summer heat and winter rest | Mildly toxic to pets |
| Betula nigra | Direct sun (at least 4-6 hours) | Keep consistently moist; tolerates wet soil | Mildly toxic to pets |
| Betula pendula | Direct sun (at least 4-6 hours) | Weekly while establishing; water in drought | Mildly toxic to pets |
| Betula pendula 'Youngii' | Direct sun (at least 4-6 hours) | Weekly while young; deep-water in dry spells | Mildly toxic to pets |
| Betula utilis var. jacquemontii | Direct sun (at least 4-6 hours) | Weekly while young; water deeply in dry summers | Mildly toxic to pets |
| Bicolor Barrenwort | Low light (north window or shaded room) | Regularly in the first season; once established, once every 2–3 weeks or rely on rainfall | Mildly toxic to pets |
| Bicolor St Dabeoc's heath | Direct sun (at least 4-6 hours) | Moderate; water regularly to keep soil moist, particularly in dry spells | Pet-safe |
| Big Blue Lilyturf | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Big Kiss Yellow Flame Gazania | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days | Pet-safe |
| Big Red Sage | Bright indirect light (just back from a sunny window) | Moderate; keep evenly moist, especially during establishment | Pet-safe |
| Bigcone Douglas Fir | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established | Pet-safe |
| Bigleaf Hydrangea 'Nikko Blue' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, often every 2-4 days in summer | Toxic to pets |
| Bigleaf Magnolia | Bright indirect light (just back from a sunny window) | Deeply twice weekly during establishment; weekly once established in dry periods | Pet-safe |
| Billy buttons | Direct sun (at least 4-6 hours) | Every 10–14 days; drought-tolerant once established | Mildly toxic to pets |
| Birchleaf Spirea | Direct sun (at least 4-6 hours) | Weekly until established; occasional watering in drought once mature | Pet-safe |
| Bird-in-a-bush | Medium indirect light (a couple of metres from a window) | Moderate in spring during active growth; dry during summer dormancy | Toxic to pets |
| Bird's Foot Fern | Bright indirect light (just back from a sunny window) | every 2-4 weeks (very drought-tolerant once established) | Mildly toxic to pets |
| Bird's Foot Fern | Bright indirect light (just back from a sunny window) | Allow the top half of soil to dry out between waterings, roughly every 10-14 days | Mildly toxic to pets |
| Bird's Nest Cactus | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, every 7-14 days in summer | Pet-safe |
| Bird's Nest Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing; deep watering when the top 5 cm of soil is dry | Pet-safe |
| Bird's-nest Orchid | Low light (north window or shaded room) | Not applicable for cultivation; in nature, reliant on consistently moist woodland humus | Mildly toxic to pets |
| Bishop of Llandaff Dahlia | Direct sun (at least 4-6 hours) | 2–3 times per week in summer | Mildly toxic to pets |
| Bishop's flower | Direct sun (at least 4-6 hours) | Every 5–7 days; less once established | Mildly toxic to pets |
| Bismarck Palm | Direct sun (at least 4-6 hours) | Regular while young; deep and infrequent once established | Mildly toxic to pets |
| Bisset's Bamboo | Direct sun (at least 4-6 hours) | Weekly during the growing season; every 2–3 weeks when dormant | Pet-safe |
| Biting Porroglossum | Medium indirect light (a couple of metres from a window) | Daily or every other day; medium must not dry out | Pet-safe |
| Bitterroot | Direct sun (at least 4-6 hours) | Winter rains / early spring only; bone dry from June to October | Pet-safe |
| Bitterroot Lewisia | Bright indirect light (just back from a sunny window) | Weekly in spring; monthly or less in summer dormancy | Pet-safe |
| Black Ash | Direct sun (at least 4-6 hours) | High; requires consistently moist to wet soil | Pet-safe |
| Black Ball cornflower | Direct sun (at least 4-6 hours) | Every 7–10 days | Pet-safe |
| Black Bamboo | Direct sun (at least 4-6 hours) | Weekly when establishing; reduce once established | Pet-safe |
| Black Beauty Elderberry | Direct sun (at least 4-6 hours) | Weekly in the first two seasons; established plants tolerate short dry spells | Mildly toxic to pets |
| Black Calla Lily | Bright indirect light (just back from a sunny window) | Generously during active growth; taper off as foliage dies back; bone dry in dormancy | Toxic to pets |
| Black Flowering Sedge | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist to wet; water whenever the surface begins to dry | Pet-safe |
| Black Knight Butterfly Bush | Direct sun (at least 4-6 hours) | Every 7-10 days during the first growing season; established plants are drought-tolerant and require supplemental watering only during extended dry spells | Toxic to pets |
| Black Knight scabiosa | Direct sun (at least 4-6 hours) | Once or twice weekly | Pet-safe |
| Black Lily Magnolia | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce in winter | Pet-safe |
| Black Medick | Direct sun (at least 4-6 hours) | Low to moderate | Pet-safe |
| Black Mondo Grass | Medium indirect light (a couple of metres from a window) | Once a week during the growing season; reduce in winter | Mildly toxic to pets |
| Black Prince snapdragon | Direct sun (at least 4-6 hours) | Every 5–7 days; keep soil consistently moist | Pet-safe |
| Black Rose Aeonium | Direct sun (at least 4-6 hours) | When the soil is dry in winter growth, sparingly during summer dormancy | Mildly toxic to pets |
| Black Spleenwort | Medium indirect light (a couple of metres from a window) | Weekly in the growing season; sparingly in winter | Mildly toxic to pets |
| Black Tree Fern | Bright indirect light (just back from a sunny window) | Daily in warm/windy conditions; 3 times per week in cool seasons | Pet-safe |
| Black-Eyed Susan | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly until established | Mildly toxic to pets |
| Black-eyed Susan 'Goldsturm' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; moderately drought-tolerant once established after the first full season | Mildly toxic to pets |
| Black-Headed Fountain Grass | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2 weeks once established | Pet-safe |
| Black-Seeded Melic | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water in dry spells, especially in lighter shade | Mildly toxic to pets |
| Black-stemmed Spleenwort | Medium indirect light (a couple of metres from a window) | When the top centimetre of substrate feels dry | Pet-safe |
| Blackhaw Viburnum | Direct sun (at least 4-6 hours) | Weekly while establishing; established plants need water only in extended drought | Pet-safe |
| Bladder Campion | Bright indirect light (just back from a sunny window) | Low; drought-tolerant | Mildly toxic to pets |
| Bladder Cherry | Direct sun (at least 4-6 hours) | Weekly in the first season; established plants tolerate moderate drought | Toxic to pets |
| Bladder Cyphostemma | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; withhold almost completely in winter dormancy | Mildly toxic to pets |
| Blanc Double de Coubert Rose | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant thereafter | Pet-safe |
| Blanket flower | Direct sun (at least 4-6 hours) | Every 7–14 days once established; water young plants more frequently | Pet-safe |
| Blanket Flower | Direct sun (at least 4-6 hours) | Water to establish, then sparingly; drought-tolerant | Mildly toxic to pets |
| Blanket Flower 'Goblin' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is fully dry, roughly every 10-14 days; minimal once established | Mildly toxic to pets |
| Blaze Improved Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, more during heat | Pet-safe |
| Blechnum chilense | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 4-6 days | Mildly toxic to pets |
| Bleeding Heart | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry; roughly weekly, keeping soil consistently moist in spring | Toxic to pets |
| Bleeding Heart | Medium indirect light (a couple of metres from a window) | Every 5–7 days in spring; taper off as foliage yellows; minimal when dormant | Toxic to pets |
| Blochman's Liveforever | Direct sun (at least 4-6 hours) | Every 10–14 days in the cool growing season (October–April); virtually none in summer | Pet-safe |
| Blonde Sedge | Bright indirect light (just back from a sunny window) | Moderate; drought-tolerant once established | Pet-safe |
| Blood-Cupped Pink | Direct sun (at least 4-6 hours) | Infrequent; highly drought-tolerant once established | Mildly toxic to pets |
| Blood-red Restrepia | Medium indirect light (a couple of metres from a window) | Every 2–4 days; keep medium consistently lightly moist | Pet-safe |
| Blood-red trumpet vine | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established. | Mildly toxic to pets |
| Bloodroot | Medium indirect light (a couple of metres from a window) | Every 5–7 days during spring growth; minimal or none during summer dormancy | Toxic to pets |
| Blue Anise Sage | Bright indirect light (just back from a sunny window) | Weekly | Pet-safe |
| Blue Arrow Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then deep occasional watering | Mildly toxic to pets |
| Blue Ash | Direct sun (at least 4-6 hours) | Regular in first 2 years; infrequent once established | Mildly toxic to pets |
| Blue Atlas Cedar | Direct sun (at least 4-6 hours) | Every 1-2 weeks while establishing, then rarely | Mildly toxic to pets |
| Blue Atlas Cedar | Direct sun (at least 4-6 hours) | Infrequently once established; moderate during first 2 years | Mildly toxic to pets |
| Blue blossom | Direct sun (at least 4-6 hours) | Weekly during establishment; minimal irrigation once established (drought-tolerant) | Mildly toxic to pets |
| Blue Boy cornflower | Direct sun (at least 4-6 hours) | Every 7–10 days | Pet-safe |
| Blue Carpet Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days for the first season, then only in extended drought | Mildly toxic to pets |
| Blue Cereus | Direct sun (at least 4-6 hours) | Every 14–21 days in summer; every 4–6 weeks in winter | Pet-safe |
| Blue Chalk Sticks | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; every 4–6 weeks in winter | Toxic to pets |
| Blue Chalk Sticks | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 12-18 days in growth | Toxic to pets |
| Blue Chalksticks | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; every 4–6 weeks in winter | Toxic to pets |
| Blue China Fir | Direct sun (at least 4-6 hours) | Deeply once per week during the first two growing seasons; established plants are fairly drought-tolerant | Mildly toxic to pets |
| Blue Cohosh | Low light (north window or shaded room) | Every 5–7 days; maintain consistently moist soil | Toxic to pets |
| Blue Columbine | Medium indirect light (a couple of metres from a window) | Water when the top 3 cm of soil dries, about weekly | Mildly toxic to pets |
| Blue Columnar Cactus | Direct sun (at least 4-6 hours) | When the top half of soil is dry, roughly every 10-14 days in summer; every 4-6 weeks in winter | Pet-safe |
| Blue Creeping Speedwell | Direct sun (at least 4-6 hours) | Moderate; allow the top few centimetres to dry between waterings | Pet-safe |
| Blue Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks | Toxic to pets |
| Blue Dendrobium | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce to every 2–3 weeks in winter | Pet-safe |
| Blue Douglas Fir | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days when young | Mildly toxic to pets |
| Blue Fescue | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; sparingly once established | Mildly toxic to pets |
| Blue Giant Sequoia | Direct sun (at least 4-6 hours) | Deeply weekly for 3–5 years during establishment | Pet-safe |
| Blue Heaven Little Bluestem | Direct sun (at least 4-6 hours) | Every 14-21 days once established; very drought-tolerant | Pet-safe |
| Blue Holly 'Blue Princess' | Bright indirect light (just back from a sunny window) | Weekly while establishing, then during dry spells | Toxic to pets |
| Blue Hosta 'Halcyon' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, about every 5-7 days | Toxic to pets |
| Blue Ice Arizona Cypress | Direct sun (at least 4-6 hours) | Every 10-14 days while establishing; drought-tolerant once established | Mildly toxic to pets |
| Blue Lyme Grass | Direct sun (at least 4-6 hours) | Drought-tolerant; water only in prolonged dry spells once established | Mildly toxic to pets |
| Blue Mistflower | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water weekly, more in heat or sandy soil | Mildly toxic to pets |
| Blue Moor Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; rarely thereafter except in extended drought | Mildly toxic to pets |
| Blue Mouse Ears Hosta | Low light (north window or shaded room) | Keep soil consistently moist, watering when the top 2-3 cm begins to dry, often weekly or more in summer | Toxic to pets |
| Blue Oat Grass | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then occasionally | Mildly toxic to pets |
| Blue Passion Flower | Direct sun (at least 4-6 hours) | Water thoroughly when the top 3-5 cm of soil is dry, roughly every 7-10 days; more frequently in hot summers, reduce significantly in winter | Toxic to pets |
| Blue Pickerelweed | Direct sun (at least 4-6 hours) | Rooted marginal — grow in wet soil or water up to 15 cm (6 in) deep | Pet-safe |
| Blue Potato Bush | Direct sun (at least 4-6 hours) | Every 4-6 days in summer, every 10-14 days in cooler months | Toxic to pets |
| Blue Prince Holly | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 7-10 days in dry spells | Toxic to pets |
| Blue Princess Holly | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 7-10 days in dry spells | Toxic to pets |
| Blue Puya | Direct sun (at least 4-6 hours) | When the soil is dry to at least 5 cm depth, roughly every 14-21 days in summer; sparingly in winter | Mildly toxic to pets |
| Blue Spruce Sedum | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer, less in winter | Pet-safe |
| Blue Spruce Stonecrop | Direct sun (at least 4-6 hours) | Every 14-21 days in spring and summer; monthly or less in winter | Pet-safe |
| Blue Spurflower | Medium indirect light (a couple of metres from a window) | Moderate — water once or twice weekly in summer; reduce significantly in winter | Mildly toxic to pets |
| Blue Star Juniper | Direct sun (at least 4-6 hours) | Water through the first season; afterward only in prolonged dry spells | Toxic to pets |
| Blue Surprise Cypress | Direct sun (at least 4-6 hours) | Keep evenly moist; deep weekly watering while establishing, then in dry periods | Toxic to pets |
| Blue Tulp | Direct sun (at least 4-6 hours) | Water sparingly in autumn and winter when growing; completely dry in summer | Toxic to pets |
| Blue Violet Iochroma | Direct sun (at least 4-6 hours) | Every 4-6 days in summer, every 10-14 days in winter | Toxic to pets |
| Blue Wild Indigo | Direct sun (at least 4-6 hours) | Water the first year; established plants rarely need watering | Mildly toxic to pets |
| Blue Wild Rye | Direct sun (at least 4-6 hours) | Water moderately when the top few cm of soil dry; avoid soggy conditions | Mildly toxic to pets |
| Blue Zinger Sedge | Direct sun (at least 4-6 hours) | Water to establish, then drought-tolerant; occasional watering in long dry spells | Mildly toxic to pets |
| Blue-Flowered Air Plant | Bright indirect light (just back from a sunny window) | Once or twice weekly | Pet-safe |
| Bluebird Mountain Hydrangea | Bright indirect light (just back from a sunny window) | Deeply once or twice a week during the growing season; reduce in autumn and winter | Mildly toxic to pets |
| bluejoint reedgrass | Direct sun (at least 4-6 hours) | Keep consistently moist to wet; suited to boggy and seasonally flooded ground | Pet-safe |
| Bluff Lettuce | Direct sun (at least 4-6 hours) | Every 3–4 weeks in winter/spring; very little to none in summer | Pet-safe |
| Bluish Sage | Direct sun (at least 4-6 hours) | Low — water when soil is dry 5–7 cm deep | Mildly toxic to pets |
| Blunt Greenhood | Medium indirect light (a couple of metres from a window) | Keep lightly moist during active growth (autumn–spring), roughly every 5-7 days | Pet-safe |
| Blushing Arisaema | Medium indirect light (a couple of metres from a window) | Regularly during growing season; minimal in dormancy | Toxic to pets |
| Blushing Dunce Cap | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; very sparingly in autumn; almost none in winter | Pet-safe |
| Boat Orchid | Bright indirect light (just back from a sunny window) | Spring-summer: keep evenly moist, roughly weekly; autumn-winter: reduce to weekly or fortnightly when barely damp | Mildly toxic to pets |
| Boat-Shaped Orthophytum | Direct sun (at least 4-6 hours) | Moderate; water every 7–10 days, allowing the medium to dry between waterings | Pet-safe |
| Bodinier's beautyberry | Direct sun (at least 4-6 hours) | Weekly during the first two growing seasons; every 2–3 weeks once established | Mildly toxic to pets |
| Boehmer's Dunce Cap | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring and summer (active growing season); once monthly or less in winter | Mildly toxic to pets |
| Bog Arum | Medium indirect light (a couple of metres from a window) | Saturated soil or up to 15 cm of standing water | Toxic to pets |
| Boke's Button Cactus | Direct sun (at least 4-6 hours) | When the mix has been dry for several days; roughly every 14-28 days in the growing season and once every 6-8 weeks in winter | Pet-safe |
| Bokhara Iris | Direct sun (at least 4-6 hours) | Moderate in spring; completely dry from midsummer to autumn | Toxic to pets |
| Bolero Painted Tongue | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Bolivian Fuchsia | Bright indirect light (just back from a sunny window) | Every 5-7 days in the growing season; every 14 days in winter | Pet-safe |
| Bolivian Torch Cactus | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; once a month or less in winter | Mildly toxic to pets |
| Bolus' Stomatium | Bright indirect light (just back from a sunny window) | Very sparingly in summer; every 2–3 weeks in autumn–spring | Pet-safe |
| Bon Bon Mix Pot Marigold | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Bonica Rose | Direct sun (at least 4-6 hours) | Deep watering once or twice weekly | Pet-safe |
| Boojum Tree | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer; monthly or less in winter | Mildly toxic to pets |
| Borchers' Oroya | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, every 10-14 days in summer | Pet-safe |
| Borchers' Schwantesia | Direct sun (at least 4-6 hours) | Every 10-14 days in the autumn-winter growing season; taper to monthly in spring; almost none in summer | Mildly toxic to pets |
| Border Forsythia | Direct sun (at least 4-6 hours) | Weekly during the first year, then only in prolonged drought | Pet-safe |
| Boscobel Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat or sandy soil | Pet-safe |
| Bosnian Pine | Direct sun (at least 4-6 hours) | Water young trees weekly in dry spells; established trees rarely need it | Mildly toxic to pets |
| Bosnian Pine 'Compact Gem' | Direct sun (at least 4-6 hours) | Water weekly in dry spells while establishing; little needed thereafter | Mildly toxic to pets |
| Botterboom | Direct sun (at least 4-6 hours) | Every 2–3 weeks in winter–spring (active), essentially none in summer (dormant) | Toxic to pets |
| Bottle Gentian | Medium indirect light (a couple of metres from a window) | Regular — keep soil consistently moist | Pet-safe |
| Bottle Palm | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Bougainvillea 'Miss Alice' | Direct sun (at least 4-6 hours) | Allow the top few centimetres of compost to dry between waterings; keeping it slightly dry encourages flowering | Mildly toxic to pets |
| Bougainvillea spectabilis | Direct sun (at least 4-6 hours) | Let the top few centimetres of soil dry between waterings; deliberately keep it on the dry side to trigger bracts | Mildly toxic to pets |
| Boulder Blue Fescue | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; sparingly once established | Mildly toxic to pets |
| Boulevard Cypress | Direct sun (at least 4-6 hours) | Every 4-7 days while establishing, then when the top few cm of soil dry | Mildly toxic to pets |
| Bove's Jerusalem Sage | Direct sun (at least 4-6 hours) | Low — once every 2–3 weeks during active growth; essentially none from late autumn to early spring | Mildly toxic to pets |
| Bowden Lily | Direct sun (at least 4-6 hours) | Minimal in summer; moderate from flowering through winter and spring while foliage is present; none once foliage dies back | Toxic to pets |
| Bower Vine | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce to every 10–14 days in cool or dry winter rest | Mildly toxic to pets |
| Bowles Golden Sedge | Direct sun (at least 4-6 hours) | Keep wet to constantly moist; never allow to dry out | Mildly toxic to pets |
| box honeysuckle | Bright indirect light (just back from a sunny window) | Regularly during the first season; drought-tolerant once established | Mildly toxic to pets |
| Bracken's Brown Beauty Magnolia | Direct sun (at least 4-6 hours) | Deeply weekly during the first 2–3 years; every 2–3 weeks once established | Mildly toxic to pets |
| Bracteate Rhinephyllum | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring–summer; minimal in winter | Pet-safe |
| Bracted Begonia | Bright indirect light (just back from a sunny window) | When the top 2–3 cm of soil is dry | Toxic to pets |
| Bradley's Spleenwort | Medium indirect light (a couple of metres from a window) | When the top 1–2 cm of substrate dries out | Pet-safe |
| Brahea Edulis | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-14 days in growth | Mildly toxic to pets |
| Brain Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in spring and summer; nearly dry through winter | Pet-safe |
| Braun's Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days; keep evenly moist | Pet-safe |
| Brazilian Waterweed | Bright indirect light (just back from a sunny window) | Permanently submerged | Pet-safe |
| Breadtree | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; every 4–6 weeks in winter | Toxic to pets |
| Brewster Lychee | Direct sun (at least 4-6 hours) | 2–3 times per week in active growth; withhold irrigation for 4–6 weeks before expected bloom | Mildly toxic to pets |
| Bridal Wreath Spirea | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil is dry, about weekly while establishing | Pet-safe |
| Bridal Wreath Spirea | Direct sun (at least 4-6 hours) | Every 7-10 days during dry spells; established plants are drought-tolerant | Pet-safe |
| Bristle-Leaved Air Plant | Bright indirect light (just back from a sunny window) | Soak weekly; mist 2–3 times per week in dry conditions | Pet-safe |
| Bristlecone Pine | Direct sun (at least 4-6 hours) | Infrequent deep watering, roughly every 2-3 weeks; allow thorough drying | Mildly toxic to pets |
| Bristly Lepanthes | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; medium kept consistently moist | Pet-safe |
| Bristol Ruby Weigela | Direct sun (at least 4-6 hours) | Every 7-10 days during dry spells; established plants cope with moderate drought | Pet-safe |
| British Yellowhead | Direct sun (at least 4-6 hours) | Once or twice per week; drought-tolerant once established | Pet-safe |
| Britt-Marie Crawford Ligularia | Medium indirect light (a couple of metres from a window) | Constantly moist to wet; never allow to dry out — water generously in any dry spell, sometimes daily in heat | Mildly toxic to pets |
| Britten's Tiger Jaws | Direct sun (at least 4-6 hours) | Every 2–4 weeks during the growing season (late summer–autumn); minimal in winter and spring | Pet-safe |
| Britten's Tiger Jaws | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season (autumn to spring); once a month or less in summer | Pet-safe |
| Broad-leaf Horncone | Bright indirect light (just back from a sunny window) | Every 1–2 weeks in the growing season; every 3–4 weeks in winter | Toxic to pets |
| Broad-leaved Grape Hyacinth | Direct sun (at least 4-6 hours) | Once per week during active spring growth; allow to dry out during summer dormancy | Toxic to pets |
| Broad-Leaved Grape Hyacinth | Bright indirect light (just back from a sunny window) | Low once established; moderate during active growth | Toxic to pets |
| Broad-leaved Pondweed | Direct sun (at least 4-6 hours) | Fully submerged aquatic; grows in 30 cm to 150 cm of water | Pet-safe |
| Broad-Leaved Primrose | Medium indirect light (a couple of metres from a window) | Regularly throughout the growing season; reduced in winter | Toxic to pets |
| Broad-Petalled Cranesbill | Bright indirect light (just back from a sunny window) | Once or twice a week in the growing season; less in winter | Pet-safe |
| Broadleaf Bamboo | Medium indirect light (a couple of metres from a window) | 2–3 times per week in summer, once per week in winter | Pet-safe |
| Broadleaf Stonecrop | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month or less in winter | Pet-safe |
| Bronze Sedge | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Mildly toxic to pets |
| Broom Palm | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-14 days in the growing season | Pet-safe |
| Brown-eyed Susan | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly weekly, more during drought | Mildly toxic to pets |
| Browning Coelogyne | Medium indirect light (a couple of metres from a window) | Evenly moist in the growing season (mid-spring to early autumn); water every 3–4 weeks in winter rest | Pet-safe |
| Bruch's Chin Cactus | Bright indirect light (just back from a sunny window) | When soil is completely dry, roughly every 10-14 days in summer; very sparingly in winter | Pet-safe |
| Brunnera macrophylla | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7 days | Mildly toxic to pets |
| Brunnera macrophylla 'Jack Frost' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Brunnera macrophylla 'Looking Glass' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Brunthal's Ice Plant | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in the growing season; every 3-4 weeks in winter | Mildly toxic to pets |
| Brush Cherry | Bright indirect light (just back from a sunny window) | Weekly when young; every 10–14 days once established | Pet-safe |
| Buccaneer Palm | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Buchanan's Sage | Bright indirect light (just back from a sunny window) | Every 5-7 days during the growing season | Pet-safe |
| Buchholz's Tylecodon | Bright indirect light (just back from a sunny window) | Every 10–14 days when actively growing (autumn–spring); once per month or less in summer | Toxic to pets |
| Bud-bearing Trisetella | Medium indirect light (a couple of metres from a window) | When the medium surface is just barely drying, roughly every 3-5 days | Pet-safe |
| Buddha's Belly Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week in warm seasons; reduce in winter | Pet-safe |
| Buddha's Temple | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in growth; minimal in winter | Toxic to pets |
| Buddleja 'Lo and Behold Blue Chip' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in dry spells | Mildly toxic to pets |
| Buddleja 'Miss Ruby' | Direct sun (at least 4-6 hours) | Weekly during establishment, then only in drought | Mildly toxic to pets |
| Buddleja alternifolia | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in drought | Mildly toxic to pets |
| Buddleja davidii 'White Profusion' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in dry spells | Mildly toxic to pets |
| Buddleja globosa | Direct sun (at least 4-6 hours) | Weekly while establishing; occasional deep watering in summer droughts once mature | Mildly toxic to pets |
| Bueck's Thelocactus | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in summer; once a month or less in winter | Pet-safe |
| Buff Beauty Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season; more in heat or against a warm wall | Pet-safe |
| Buffalo Cow Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, approximately every 14-21 days in summer | Pet-safe |
| Bugle | Medium indirect light (a couple of metres from a window) | Moderate; keep evenly moist but never waterlogged | Pet-safe |
| Bulb Sparaxis | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 10-14 days in spring | Mildly toxic to pets |
| Bulbil Bugle Lily | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days during active growth | Mildly toxic to pets |
| Bulbous Corydalis | Medium indirect light (a couple of metres from a window) | Rely on natural rainfall during spring growth; no irrigation needed once dormant in summer | Toxic to pets |
| Bunch-flowered Narcissus | Bright indirect light (just back from a sunny window) | Moderate and consistent during active growth; reduce sharply as foliage yellows; dormant dry | Toxic to pets |
| Bunny Ear Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 10-14 days in summer; every 4-6 weeks in autumn; once a month or less in winter | Mildly toxic to pets |
| Burchard's Caralluma | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and autumn; very sparingly in summer and winter | Mildly toxic to pets |
| Burgundy Glow Bugle | Medium indirect light (a couple of metres from a window) | Moderate; consistently moist but not waterlogged | Mildly toxic to pets |
| Burgundy Lace Japanese Painted Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season, reduce significantly in winter dormancy | Pet-safe |
| Burkwood Viburnum | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil dries, roughly weekly during establishment | Pet-safe |
| Burnet Rose | Direct sun (at least 4-6 hours) | Weekly during establishment; rarely once mature | Pet-safe |
| Burrawang | Medium indirect light (a couple of metres from a window) | Water every 2–3 weeks in growing season, monthly or less in winter | Toxic to pets |
| Burrawang Palm | Bright indirect light (just back from a sunny window) | Every 2–3 weeks | Toxic to pets |
| Burser's Saxifrage | Bright indirect light (just back from a sunny window) | Every 7–10 days during growth; minimal in winter | Pet-safe |
| Bush Cycad | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season; monthly or less in winter | Toxic to pets |
| Bush Muhly | Direct sun (at least 4-6 hours) | Every 14-21 days during establishment; essentially rainfall-dependent once established in suitable climates | Pet-safe |
| Bush Vetch | Bright indirect light (just back from a sunny window) | Low to moderate — maintain moderate soil moisture | Mildly toxic to pets |
| Bushgrass | Medium indirect light (a couple of metres from a window) | Moderate — water regularly to establish, then largely drought-tolerant | Pet-safe |
| Bushy Aichryson | Bright indirect light (just back from a sunny window) | Every 10–15 days in summer (growing season); once monthly in winter | Mildly toxic to pets |
| Bushy Bluestem | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Butomus umbellatus | Direct sun (at least 4-6 hours) | Constantly wet; shallow margin | Mildly toxic to pets |
| Butterfield Holly Fern | Low light (north window or shaded room) | Every 7–14 days; much less in winter | Pet-safe |
| Butterfly bush | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; drought-tolerant once established | Mildly toxic to pets |
| Butterfly Bush 'Black Knight' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry; weekly in the first season, then only in prolonged drought | Mildly toxic to pets |
| Butterfly Bush 'Pink Delight' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry; weekly through the first year, then sparingly | Mildly toxic to pets |
| Butterfly Weed | Direct sun (at least 4-6 hours) | Water to establish, then only during prolonged drought; mature plants rarely need watering | Toxic to pets |
| Button Cactus | Direct sun (at least 4-6 hours) | When fully dry, about every 10-14 days in summer; keep nearly dry in winter | Pet-safe |
| Button Cactus | Direct sun (at least 4-6 hours) | When the mix is completely dry, roughly every 14-21 days in summer; once a month or less in winter | Pet-safe |
| Byzantine Colchicum | Bright indirect light (just back from a sunny window) | Relies on natural rainfall; do not water during summer dormancy | Toxic to pets |
| Byzantine Gladiolus | Direct sun (at least 4-6 hours) | Moderate during spring growth; minimal in summer after dormancy | Toxic to pets |
| Byzantine Meadow Saffron | Bright indirect light (just back from a sunny window) | Relies on natural rainfall; needs no supplementary watering once established | Toxic to pets |
| Café au Lait Dahlia | Direct sun (at least 4-6 hours) | 2–3 times per week | Mildly toxic to pets |
| Calceolaria Herbeohybrida | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feels dry, roughly every 2-4 days while in flower | Mildly toxic to pets |
| Calendula | Direct sun (at least 4-6 hours) | Moderate — roughly weekly once established | Pet-safe |
| Calendula 'Indian Prince' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil is dry, roughly weekly | Pet-safe |
| Calendula 'Radio' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil is dry, roughly weekly | Pet-safe |
| Calico Aster | Bright indirect light (just back from a sunny window) | Water to establish, then occasionally; tolerates dry soil | Pet-safe |
| Calico flower | Medium indirect light (a couple of metres from a window) | Once or twice a week during the growing season; once a week or less in winter. | Toxic to pets |
| Califano's Dioon | Direct sun (at least 4-6 hours) | Every 3–5 weeks in summer; once every 6–8 weeks in winter | Toxic to pets |
| California Fescue | Bright indirect light (just back from a sunny window) | Water every 10-14 days during the first growing season; established plants are summer-dormant and very drought-tolerant, needing little or no supplemental water | Pet-safe |
| California Giant Chain Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days; keep soil consistently moist but not waterlogged | Pet-safe |
| California Juniper | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, often every 3-5 days in heat | Mildly toxic to pets |
| California Maidenhair Fern | Medium indirect light (a couple of metres from a window) | Every 3–5 days in the growing season; every 7–10 days in winter (dormant period) | Pet-safe |
| California Polypody | Medium indirect light (a couple of metres from a window) | Weekly in autumn to spring; reduce to monthly or suspend in summer | Mildly toxic to pets |
| California poppy | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; more frequent during germination | Mildly toxic to pets |
| California Shield Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days in growing season; reduce in winter | Pet-safe |
| California Sunset | Direct sun (at least 4-6 hours) | Every 10–14 days in spring/summer; every 3–4 weeks in autumn/winter | Pet-safe |
| Callicarpa 'Pearl Glam' | Direct sun (at least 4-6 hours) | Water weekly during the first season; established plants are fairly drought-tolerant and need water mainly in dry spells | Pet-safe |
| Callicarpa americana | Bright indirect light (just back from a sunny window) | Water weekly while establishing; once established, only during prolonged drought | Mildly toxic to pets |
| Callicarpa bodinieri var. giraldii 'Profusion' | Bright indirect light (just back from a sunny window) | Water weekly during establishment and in dry spells; established plants are moderately drought-tolerant | Mildly toxic to pets |
| Callicarpa dichotoma | Bright indirect light (just back from a sunny window) | Water weekly during establishment and dry periods; moderately drought-tolerant once established | Mildly toxic to pets |
| Callicarpa japonica | Bright indirect light (just back from a sunny window) | Water weekly while establishing and during droughts; moderately drought-tolerant once settled | Mildly toxic to pets |
| Caltha palustris | Direct sun (at least 4-6 hours) | Keep wet at all times; saturated soil or shallow water | Toxic to pets |
| Caltha palustris 'Flore Pleno' | Direct sun (at least 4-6 hours) | Keep wet at all times; saturated soil or shallow water | Toxic to pets |
| Camassia leichtlinii | Direct sun (at least 4-6 hours) | Keep soil consistently moist in spring during active growth; tolerates dry dormancy in summer | Mildly toxic to pets |
| Cambuci | Direct sun (at least 4-6 hours) | Weekly; more frequent during fruit development | Mildly toxic to pets |
| Camellia 'Alba Plena' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, every 7-10 days during active growth | Pet-safe |
| Camellia 'Anticipation' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days during the growing season | Pet-safe |
| Camellia 'Bob Hope' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during the growing season | Pet-safe |
| Camellia 'Brushfield's Yellow' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost or soil is dry, roughly every 5-7 days during active growth | Pet-safe |
| Camellia 'Debbie' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Camellia 'Dixie Knight' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil or compost is dry, roughly every 5-7 days in the growing season | Pet-safe |
| Camellia 'Donation' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist in late summer | Pet-safe |
| Camellia 'Elegans' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during growth | Pet-safe |
| Camellia 'Hagoromo' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost or soil is dry, roughly every 5-7 days during active growth | Pet-safe |
| Camellia 'J.C. Williams' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days during the growing season | Pet-safe |
| Camellia 'Jury's Yellow' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply once or twice weekly in summer, especially during bud set | Pet-safe |
| Camellia 'Jury's Yellow' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days during active growth | Pet-safe |
| Camellia 'Kramer's Supreme' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during active growth | Pet-safe |
| Camellia 'Midnight Magic' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, roughly every 7-10 days during active growth | Pet-safe |
| Camellia 'Mine-no-Yuki' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days through the growing season | Pet-safe |
| Camellia 'Nuccio's Gem' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, roughly every 7-10 days in active growth | Pet-safe |
| Camellia 'Spring Festival' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Pet-safe |
| Camellia 'Water Lily' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil or compost is dry, roughly every 5-7 days during the growing season | Pet-safe |
| Camellia 'Yuletide' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during active growth | Pet-safe |
| Cameroon Cycad | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season; monthly in winter | Toxic to pets |
| Campanula glomerata 'Superba' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, about weekly in dry spells | Pet-safe |
| Campanula lactiflora 'Loddon Anna' | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply in dry spells, roughly weekly once established | Mildly toxic to pets |
| Campanula persicifolia | Direct sun (at least 4-6 hours) | Water during establishment and dry spells; roughly weekly in summer drought once settled | Mildly toxic to pets |
| Campanula portenschlagiana | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly weekly in summer | Mildly toxic to pets |
| Campanula poscharskyana | Bright indirect light (just back from a sunny window) | When the top few centimetres of soil dry out, weekly in hot spells | Mildly toxic to pets |
| Campanula punctata | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry; keep consistently moist in summer | Mildly toxic to pets |
| Campbell's Lycaste | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; reduce sharply after leaf drop | Pet-safe |
| Campbell's Magnolia | Direct sun (at least 4-6 hours) | Every 7-10 days during the first three growing seasons; established trees need watering only during prolonged summer drought | Pet-safe |
| Campos Porto Fuchsia | Bright indirect light (just back from a sunny window) | Regular during growth; reduce in winter | Pet-safe |
| Campsis grandiflora | Direct sun (at least 4-6 hours) | When the top 5 cm of soil dries, about every 7-10 days while establishing | Mildly toxic to pets |
| Campsis radicans | Direct sun (at least 4-6 hours) | When the top 5 cm of soil dries, about every 7-14 days for young plants | Mildly toxic to pets |
| Campsis x tagliabuana 'Madame Galen' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil dries, about every 7-14 days while establishing | Mildly toxic to pets |
| Can Can Heuchera | Bright indirect light (just back from a sunny window) | Keep evenly moist; water when the top 2-3 cm is dry, about every 5-7 days in summer | Pet-safe |
| Canada Mayflower | Low light (north window or shaded room) | 2–3 times per week during the growing season; minimal in dormancy | Mildly toxic to pets |
| Canada Violet | Medium indirect light (a couple of metres from a window) | Weekly; more frequently in warm or dry periods | Mildly toxic to pets |
| Canadian Lousewort | Medium indirect light (a couple of metres from a window) | Regularly; keep soil evenly moist | Mildly toxic to pets |
| Canadian Waterweed | Medium indirect light (a couple of metres from a window) | Permanently submerged | Pet-safe |
| Canary creeper | Bright indirect light (just back from a sunny window) | Water regularly to keep soil evenly moist, roughly every 5–7 days | Pet-safe |
| Canary Island Monanthes | Bright indirect light (just back from a sunny window) | Every 3–4 weeks in spring and summer; once monthly or less in autumn and winter | Mildly toxic to pets |
| Canary Island Sage | Direct sun (at least 4-6 hours) | Every 10-14 days; minimal in cool or wet periods | Pet-safe |
| Canary Reed Grass | Bright indirect light (just back from a sunny window) | Keep consistently moist to wet; tolerates standing water | Mildly toxic to pets |
| Candelabra Lily | Direct sun (at least 4-6 hours) | Water moderately from first autumn rains (flower emergence) through winter-spring leaf period; keep bone dry all summer | Toxic to pets |
| Candelabra Sage | Direct sun (at least 4-6 hours) | Every 10-14 days in the growing season | Pet-safe |
| Candelabra Tylecodon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn–spring (active), near-zero in summer (dormant) | Toxic to pets |
| Candelabrum Liveforever | Direct sun (at least 4-6 hours) | Every 1–2 weeks in autumn and winter; minimal in spring; none in summer | Pet-safe |
| Candia Sulcorebutia | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; virtually none from October to March | Pet-safe |
| Candle larkspur | Direct sun (at least 4-6 hours) | Regular — deep watering 2–3 times per week during active growth; reduce in dormancy | Toxic to pets |
| Candle Larkspur 'Guardian Blue' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Candle plant | Bright indirect light (just back from a sunny window) | When the soil is fully dry; roughly every 2-3 weeks in growth, far less in summer dormancy | Toxic to pets |
| Candle Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks during autumn and spring active growth; once a month or less in summer dormancy | Toxic to pets |
| Candy Cane Sorrel | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during active growth | Mildly toxic to pets |
| Candy Stripe Creeping Phlox | Direct sun (at least 4-6 hours) | Every 7–10 days during the establishment year; drought-tolerant thereafter | Pet-safe |
| Canigueral's Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; once a month during winter dormancy | Pet-safe |
| Cantabrian Draba | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Canton Fishtail Palm | Bright indirect light (just back from a sunny window) | Regularly; keep soil consistently moist | Mildly toxic to pets |
| Canyon Liveforever | Direct sun (at least 4-6 hours) | Every 2–3 weeks in winter/spring; minimal to none in summer | Pet-safe |
| Canyon Sage | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established | Pet-safe |
| Cape Bugle Lily | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during active growth | Mildly toxic to pets |
| Cape daisy | Direct sun (at least 4-6 hours) | Every 4–6 days once established; more frequently in containers during warm weather | Mildly toxic to pets |
| Cape Fockea | Bright indirect light (just back from a sunny window) | Every 10–14 days during spring and summer growing season; once a month or less in winter | Mildly toxic to pets |
| Cape honeysuckle | Direct sun (at least 4-6 hours) | Weekly when young; every 2–4 weeks once established. | Mildly toxic to pets |
| Cape jewels | Direct sun (at least 4-6 hours) | Every 3–5 days in containers; every 5–7 days in borders | Pet-safe |
| Cape Leadwort (Blue Plumbago) | Direct sun (at least 4-6 hours) | Weekly in active growth; let the top of the soil dry between waterings | Mildly toxic to pets |
| Cape Mallow | Direct sun (at least 4-6 hours) | Water when the top 2–3 cm of soil is dry | Mildly toxic to pets |
| Cape Sundew | Bright indirect light (just back from a sunny window) | Keep substrate continuously moist via the tray method — sit pot in 1–2 cm of water at all times | Mildly toxic to pets |
| Caradonna Salvia | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly until established | Pet-safe |
| Caranday Palm | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in summer; every 3-4 weeks in dry season / winter | Pet-safe |
| Cardinal Royal rowan | Direct sun (at least 4-6 hours) | Regular during the first season; drought-tolerant once established | Mildly toxic to pets |
| Cardinal Sage | Bright indirect light (just back from a sunny window) | Freely during active growth; sparingly in winter | Pet-safe |
| Carding Mill Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week through the growing season, more in heat | Pet-safe |
| Carefree Wonder Rose | Direct sun (at least 4-6 hours) | Deep soak once or twice a week depending on heat | Pet-safe |
| Carex pendula | Medium indirect light (a couple of metres from a window) | Keep soil moist; water in dry spells | Mildly toxic to pets |
| Carex riparia 'Variegata' | Direct sun (at least 4-6 hours) | Keep wet to shallowly submerged at all times | Mildly toxic to pets |
| Carmen's Pincushion | Direct sun (at least 4-6 hours) | Every 10-14 days in the spring-summer growing season when the top 2-3 cm of soil is dry; every 4-6 weeks or less in winter | Pet-safe |
| Carnarvon Fan Palm | Direct sun (at least 4-6 hours) | Weekly during active growth; every 2–3 weeks when established | Pet-safe |
| Carnauba Wax Palm | Direct sun (at least 4-6 hours) | When the top 5-10 cm of soil is dry, roughly every 10-14 days in the growing season; every 3-5 weeks in winter | Pet-safe |
| Carnivorous Bromeliad | Direct sun (at least 4-6 hours) | Keep the central tank filled with distilled or rainwater; water the substrate when the surface begins to dry, roughly every 5-7 days | Pet-safe |
| Carol's Ruschia | Direct sun (at least 4-6 hours) | When soil is completely dry, approximately every 10-14 days in spring-summer; once monthly or less in winter | Pet-safe |
| Carolina Hemlock | Bright indirect light (just back from a sunny window) | Weekly during establishment; monthly deep watering once established in cool climates | Pet-safe |
| Carousel Little Bluestem | Direct sun (at least 4-6 hours) | Every 14-21 days during establishment; minimal once established | Pet-safe |
| Carpathian bellflower | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; moderate moisture needs | Pet-safe |
| Carrot-leaved Pelargonium | Direct sun (at least 4-6 hours) | Water when the top 2–3 cm of compost is dry during growth (autumn–spring); completely dry in summer dormancy | Toxic to pets |
| Caryopteris incana | Direct sun (at least 4-6 hours) | Weekly while establishing, then only during drought | Mildly toxic to pets |
| Caryopteris x clandonensis 'Dark Knight' | Direct sun (at least 4-6 hours) | Weekly during establishment, then sparingly in dry spells | Mildly toxic to pets |
| Caryopteris x clandonensis 'Heavenly Blue' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only during prolonged drought | Mildly toxic to pets |
| Caryopteris x clandonensis 'Worcester Gold' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in drought | Mildly toxic to pets |
| Cascade Purple Aubrieta | Direct sun (at least 4-6 hours) | Weekly during active growth; minimal in summer dormancy | Pet-safe |
| Cascade White Trailing Lobelia | Bright indirect light (just back from a sunny window) | When the top 2 cm of compost is dry, roughly every 2-4 days (more frequent in hot weather) | Toxic to pets |
| Cascadia trailing petunia | Direct sun (at least 4-6 hours) | Every 2-3 days in warm weather; check daily in summer heat | Pet-safe |
| Cast iron plant | Low light (north window or shaded room) | When the top 3 cm of soil is dry, every 10-14 days | Pet-safe |
| Cast Iron Plant | Low light (north window or shaded room) | When the top half of the soil is dry, roughly every 10-14 days | Toxic to pets |
| Castilian Heron's Bill | Direct sun (at least 4-6 hours) | Water sparingly every 10-14 days in the growing season; almost none from late autumn to spring | Mildly toxic to pets |
| Castlewellan Cypress | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days for young plants | Mildly toxic to pets |
| Cat's Claw Creeper | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant when established | Mildly toxic to pets |
| Cat's Claw Vine | Direct sun (at least 4-6 hours) | Every 7–14 days; highly drought-tolerant once established | Mildly toxic to pets |
| Cat's Claw Vine | Direct sun (at least 4-6 hours) | Water every 7-14 days during establishment; extremely drought-tolerant once established and rarely needs supplemental watering | Mildly toxic to pets |
| Cat's Jaws | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in growth and much less in summer rest | Mildly toxic to pets |
| Cat's Jaws | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10–14 days in spring and summer; reduce to once a month or less in winter | Mildly toxic to pets |
| Cat's-ear | Direct sun (at least 4-6 hours) | Low — very drought-tolerant once established | Mildly toxic to pets |
| Catalpa bignonioides | Direct sun (at least 4-6 hours) | Weekly while young; established trees are fairly drought-tolerant | Mildly toxic to pets |
| Catalpa bignonioides 'Aurea' | Direct sun (at least 4-6 hours) | Weekly while establishing; moderate drought tolerance when mature | Mildly toxic to pets |
| Catalpa speciosa | Direct sun (at least 4-6 hours) | Weekly when young; notably drought-tolerant once established | Mildly toxic to pets |
| Catawba rhododendron | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 7–14 days once established | Toxic to pets |
| Catawba Rhododendron 'Roseum Elegans' | Bright indirect light (just back from a sunny window) | About weekly, deeper in heat and drought; water when the top 3-5 cm of soil is dry | Toxic to pets |
| Catesby's Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method with seasonal reduction | Pet-safe |
| Catesby's Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist in spring; reduce after summer dormancy | Mildly toxic to pets |
| Cathaya argyrophylla | Bright indirect light (just back from a sunny window) | When the top few cm of soil begins to dry, roughly every 5-7 days for young plants in growth | Mildly toxic to pets |
| Catmint 'Walker's Low' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days during the growing season | Mildly toxic to pets |
| Caucasian Comfrey | Medium indirect light (a couple of metres from a window) | Every 5–7 days during dry spells; self-sufficient in rainy climates | Mildly toxic to pets |
| Caucasian Draba | Direct sun (at least 4-6 hours) | Low — water only when soil is dry | Mildly toxic to pets |
| Caucasian Rock Cress | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Caucasian Scabious | Direct sun (at least 4-6 hours) | Water regularly while establishing and during dry spells, otherwise when the top few centimetres of soil are dry | Mildly toxic to pets |
| Cautley Roscoea | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry during the growing season, approximately every 7-14 days; reduce to very low or none in winter dormancy | Mildly toxic to pets |
| Cavatine pieris | Bright indirect light (just back from a sunny window) | Weekly; keep consistently moist | Toxic to pets |
| Ceanothus 'Concha' | Direct sun (at least 4-6 hours) | Water to establish, then little to no summer water once mature | Mildly toxic to pets |
| Ceanothus 'Puget Blue' | Direct sun (at least 4-6 hours) | Water to establish, then little to no summer water once mature | Mildly toxic to pets |
| Ceanothus 'Victoria' | Direct sun (at least 4-6 hours) | Water to establish in year one, then little to no summer water once settled | Mildly toxic to pets |
| Ceanothus americanus | Direct sun (at least 4-6 hours) | Weekly during the first season; rarely thereafter once established | Mildly toxic to pets |
| Ceanothus thyrsiflorus 'Skylark' | Direct sun (at least 4-6 hours) | Water to establish, then only occasional water; more summer-water tolerant than most ceanothus | Mildly toxic to pets |
| Cecile Brunner Climbing Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while young; established plants are fairly drought-tolerant and need water mainly in dry spells | Pet-safe |
| Cedar of Lebanon | Direct sun (at least 4-6 hours) | Weekly during first 3 years; very drought-tolerant once established | Mildly toxic to pets |
| Cedros Island Liveforever | Direct sun (at least 4-6 hours) | Every 4–6 weeks in summer (dormant), every 2–3 weeks in winter–spring (active) | Pet-safe |
| Celandine Poppy | Medium indirect light (a couple of metres from a window) | 2 times per week during spring and early summer; reduce as plant self-senesces | Mildly toxic to pets |
| Centaurea 'Amethyst in Snow' | Direct sun (at least 4-6 hours) | Weekly through the first season; established clumps are drought-tolerant | Pet-safe |
| Central Australian Cabbage Palm | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry between waterings | Pet-safe |
| Central Australian Cabbage Palm | Direct sun (at least 4-6 hours) | Water deeply every 14-21 days; highly drought-tolerant once established | Pet-safe |
| Cephalophyllum tricolorum | Direct sun (at least 4-6 hours) | Only when the soil is fully dry, roughly every 10-14 days in growth; keep nearly dry when dormant | Mildly toxic to pets |
| Cephalotaxus 'Fastigiata' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, roughly weekly while establishing | Mildly toxic to pets |
| Cephalotus follicularis 'Eden Black' | Bright indirect light (just back from a sunny window) | Keep lightly moist; let the surface just begin to dry between waterings | Mildly toxic to pets |
| Cercidiphyllum japonicum | Bright indirect light (just back from a sunny window) | Weekly, keeping the soil consistently moist, especially in summer | Mildly toxic to pets |
| Cercidiphyllum japonicum 'Pendulum' | Bright indirect light (just back from a sunny window) | Weekly, keeping soil consistently moist, particularly in summer | Mildly toxic to pets |
| Cercis canadensis 'Forest Pansy' | Direct sun (at least 4-6 hours) | Weekly while establishing; deep soak during dry spells | Mildly toxic to pets |
| Cercis canadensis 'Lavender Twist' | Direct sun (at least 4-6 hours) | Weekly while establishing; supplement in drought | Mildly toxic to pets |
| Cercis siliquastrum | Direct sun (at least 4-6 hours) | Water regularly while young; rarely once established | Mildly toxic to pets |
| Ceylon Date Palm | Direct sun (at least 4-6 hours) | Weekly during active growth; every 2–3 weeks in cooler or drier periods | Mildly toxic to pets |
| Chagual | Direct sun (at least 4-6 hours) | every 7–14 days in summer, rarely in winter | Pet-safe |
| Chain Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 4-6 days | Mildly toxic to pets |
| Chain Pleurothallis | Bright indirect light (just back from a sunny window) | Every 2-3 days; do not allow to dry completely | Pet-safe |
| Chalk Liveforever | Direct sun (at least 4-6 hours) | Every 3–5 weeks in winter/spring; suspend in summer | Pet-safe |
| Chalk Milkwort | Direct sun (at least 4-6 hours) | Infrequently; drought-tolerant once established | Mildly toxic to pets |
| Chamaedorea Microspadix | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Chamaerops Humilis 'Vulcano' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, every 7-14 days in summer | Pet-safe |
| Chamaerops Humilis Cerifera | Direct sun (at least 4-6 hours) | When the top few cm of soil are dry; drought-tolerant once established | Pet-safe |
| Chandelier Plant | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in summer | Toxic to pets |
| Chanet's Dunce Cap | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; monthly or less in winter | Pet-safe |
| Changing Tibouchina | Direct sun (at least 4-6 hours) | Water regularly to maintain evenly moist soil during the growing season; reduce slightly in winter. | Mildly toxic to pets |
| Chanticleer ornamental pear | Direct sun (at least 4-6 hours) | Weekly for first 2 years; drought-tolerant once established | Mildly toxic to pets |
| Chantilly Peach snapdragon | Direct sun (at least 4-6 hours) | Every 5–7 days; keep soil evenly moist but not waterlogged | Pet-safe |
| Chaparensis Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in hot weather; every 2–3 days in cooler seasons | Pet-safe |
| Charles Joly Lilac | Direct sun (at least 4-6 hours) | Every 7-10 days during dry periods; drought-tolerant once established | Mildly toxic to pets |
| Charlotte Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; more in heat | Pet-safe |
| Cheddar Pink | Direct sun (at least 4-6 hours) | Sparingly — every 1–2 weeks in summer | Mildly toxic to pets |
| Cheiridopsis candidissima | Direct sun (at least 4-6 hours) | Autumn through spring; keep dry during summer dormancy | Mildly toxic to pets |
| Cheiridopsis denticulata | Direct sun (at least 4-6 hours) | Autumn through spring; keep dry through summer dormancy | Mildly toxic to pets |
| Cheiridopsis pillansii | Direct sun (at least 4-6 hours) | Only during autumn-to-spring growth when soil is fully dry; near-zero in summer dormancy | Mildly toxic to pets |
| Cheiridopsis robusta | Direct sun (at least 4-6 hours) | During autumn-spring growth when soil is bone dry; withhold through summer | Mildly toxic to pets |
| Cheiridopsis turbinata | Direct sun (at least 4-6 hours) | In autumn-spring growth once soil is fully dry; minimal in summer dormancy | Mildly toxic to pets |
| Cherokee Chief Dogwood | Bright indirect light (just back from a sunny window) | Weekly deep watering; more in summer drought | Pet-safe |
| Cherry of the Rio Grande | Direct sun (at least 4-6 hours) | Water 2–3 times per week during warm months; once weekly in cooler, dormant periods. | Pet-safe |
| Cheshunt Pine | Bright indirect light (just back from a sunny window) | Water regularly to keep soil evenly moist; once or twice weekly in summer | Mildly toxic to pets |
| Chestnut Dioon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month or less in winter | Toxic to pets |
| Chestnut-Flowered Sage | Medium indirect light (a couple of metres from a window) | Regular — keep soil evenly moist through the growing season | Mildly toxic to pets |
| Chiapas Sage | Medium indirect light (a couple of metres from a window) | Moderate — water when the top 2 cm of soil is dry | Pet-safe |
| Chilean Blue Crocus | Direct sun (at least 4-6 hours) | Regular watering during the spring growing season; completely dry from late spring through late autumn | Mildly toxic to pets |
| Chilean Bromeliad | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | Mildly toxic to pets |
| Chilean Butterwort | Bright indirect light (just back from a sunny window) | Water from below by brief tray sitting every 5-10 days when the soil surface begins to dry; dry out slightly between waterings in winter | Pet-safe |
| Chilean Hard Fern | Medium indirect light (a couple of metres from a window) | Keep consistently moist — water when the top 1-2 cm of soil is dry, typically every 5-7 days indoors | Pet-safe |
| Chilean Wine Palm | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 10-14 days while establishing, infrequently once mature | Mildly toxic to pets |
| Chiltern Gentian | Direct sun (at least 4-6 hours) | Minimal supplementary watering needed; moderate natural rainfall is adequate | Mildly toxic to pets |
| Chin Cactus | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring/summer; every 3–4 weeks in autumn; withhold in winter | Pet-safe |
| China Fir | Direct sun (at least 4-6 hours) | Keep soil moist; water regularly while young, then deeply during dry spells once established | Mildly toxic to pets |
| China Girl dogwood | Bright indirect light (just back from a sunny window) | Weekly in first 2–3 years; every 1–2 weeks in dry periods once established | Mildly toxic to pets |
| China pink | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; reduce in cool weather | Mildly toxic to pets |
| Chinese Astilbe 'Visions' | Bright indirect light (just back from a sunny window) | Keep soil reliably moist; water every 3-5 days in summer | Mildly toxic to pets |
| Chinese Astilbe 'Visions' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer; more drought-tolerant than most astilbes | Mildly toxic to pets |
| Chinese Brake Fern | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil is dry, roughly every 5-7 days in spring and summer | Mildly toxic to pets |
| Chinese Douglas Fir | Direct sun (at least 4-6 hours) | Weekly when young; every 2 weeks once established | Pet-safe |
| Chinese Dunce Cap | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season (spring–summer); sparingly in winter | Pet-safe |
| Chinese Dwarf Bamboo | Medium indirect light (a couple of metres from a window) | Once or twice per week during the growing season; reduce in winter | Pet-safe |
| Chinese Enkianthus | Bright indirect light (just back from a sunny window) | Regularly throughout the growing season | Mildly toxic to pets |
| Chinese Fan Palm | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil dries out, roughly every 7-14 days | Pet-safe |
| Chinese Flowering Quince | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil approaches dry, often daily in summer heat | Mildly toxic to pets |
| Chinese Gentian | Direct sun (at least 4-6 hours) | Regular, keeping soil evenly moist throughout the growing season; reduce in winter | Mildly toxic to pets |
| Chinese Ground Orchid | Bright indirect light (just back from a sunny window) | Keep evenly moist during active growth (spring and summer), watering every 5-7 days; allow to dry out naturally in autumn as the plant goes dormant | Pet-safe |
| Chinese Hackberry | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil dries, often daily in summer | Mildly toxic to pets |
| Chinese Hemlock | Bright indirect light (just back from a sunny window) | Every 1–2 weeks when young; every 2–3 weeks once established | Pet-safe |
| Chinese Holly Fern | Low light (north window or shaded room) | Every 6–10 days in summer, every 12–16 days in winter | Pet-safe |
| Chinese Incense Cedar | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days for young plants | Mildly toxic to pets |
| Chinese Jade | Bright indirect light (just back from a sunny window) | Every 2–4 weeks (allow soil to dry completely between waterings) | Mildly toxic to pets |
| Chinese Juniper 'Itoigawa' | Direct sun (at least 4-6 hours) | When the soil surface is approaching dry, then water thoroughly | Mildly toxic to pets |
| Chinese Lantern Plant | Direct sun (at least 4-6 hours) | Weekly during growing season; drought-tolerant once established | Toxic to pets |
| Chinese Larch | Direct sun (at least 4-6 hours) | Regular during establishment and growing season; reduced in dormancy | Pet-safe |
| Chinese peony | Direct sun (at least 4-6 hours) | Moderate — once or twice weekly during active growth; reduce significantly after foliage dies back in autumn | Mildly toxic to pets |
| Chinese Plum Yew | Medium indirect light (a couple of metres from a window) | Keep evenly moist; weekly in dry spells, more while establishing | Mildly toxic to pets |
| Chinese Premna | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil dries, often daily in warm growth | Mildly toxic to pets |
| Chinese Redbud | Direct sun (at least 4-6 hours) | Every 7-10 days during the first two growing seasons; established plants roughly every 14 days in dry spells | Toxic to pets |
| Chinese Swamp Cypress | Direct sun (at least 4-6 hours) | Keep consistently moist to wet; tolerates prolonged inundation | Mildly toxic to pets |
| Chinese Sweetgum | Direct sun (at least 4-6 hours) | Weekly during the growing season; reduce in winter | Mildly toxic to pets |
| Chinese Timber Bamboo | Direct sun (at least 4-6 hours) | 2–3 times per week in the shooting season (spring); weekly otherwise | Pet-safe |
| Chinese Trumpet Creeper | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days once established | Toxic to pets |
| Chinese Tupelo | Bright indirect light (just back from a sunny window) | Regularly during establishment; once or twice a week in dry spells | Pet-safe |
| Chinese Tylecodon | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (autumn–spring); minimal or none in summer | Toxic to pets |
| Chinese Weeping Cypress | Direct sun (at least 4-6 hours) | Regular during establishment; drought-tolerant once mature | Pet-safe |
| Chinese White Pine | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry; allow slight drying between waterings | Mildly toxic to pets |
| Chinese Windmill Palm 'Bulgaria' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly weekly in summer | Toxic to pets |
| Chinese witch hazel | Bright indirect light (just back from a sunny window) | Regularly during establishment (first 2–3 years); once established, during dry periods in summer | Mildly toxic to pets |
| Chinese Witch Hazel | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in the growing season | Mildly toxic to pets |
| Chinese woodbine | Medium indirect light (a couple of metres from a window) | Weekly; do not allow the root zone to dry out | Mildly toxic to pets |
| Chionodoxa luciliae | Direct sun (at least 4-6 hours) | Rainfall in most settings; rarely needs watering | Mildly toxic to pets |
| Chocolate orchid | Bright indirect light (just back from a sunny window) | When the mix is nearly dry, roughly every 5-9 days | Pet-safe |
| Choisya 'Sundance' | Direct sun (at least 4-6 hours) | Water weekly while establishing, then only during extended dry periods | Mildly toxic to pets |
| Choisya 'White Dazzler' | Bright indirect light (just back from a sunny window) | Water weekly while establishing; mature plants need water only in dry spells | Mildly toxic to pets |
| Choisya ternata | Direct sun (at least 4-6 hours) | Water deeply once a week through the first two seasons, then only in prolonged dry spells | Mildly toxic to pets |
| Choisya x dewitteana 'Aztec Pearl' | Direct sun (at least 4-6 hours) | Water weekly through the first two years, then only in dry spells | Mildly toxic to pets |
| Christmas Carol Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 1-2 weeks in summer | Toxic to pets |
| Christmas Fern | Low light (north window or shaded room) | When the top 3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Christmas Rose | Medium indirect light (a couple of metres from a window) | Keep evenly moist while establishing and during summer drought; established plants tolerate moderate dryness | Toxic to pets |
| Christmas Tree Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 14-21 days in the growing season and once a month or less in winter | Pet-safe |
| Chrysanthemum 'Anastasia' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Chrysanthemum 'Bronze Elegance' | Direct sun (at least 4-6 hours) | Every 5-7 days when the top 2-3 cm of soil is dry; more frequently in hot weather | Toxic to pets |
| Chrysanthemum 'Cheryl Pride' | Direct sun (at least 4-6 hours) | Every 4-6 days, allowing the top 2-3 cm of soil to dry | Toxic to pets |
| Chrysanthemum 'Cottage Apricot' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chrysanthemum 'Country Girl' | Direct sun (at least 4-6 hours) | Every 5-7 days in summer; reduce in autumn as growth slows | Toxic to pets |
| Chrysanthemum 'Emperor of China' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7 days | Toxic to pets |
| Chrysanthemum 'Golden Cascade' | Direct sun (at least 4-6 hours) | Every 3-5 days for container-grown plants; every 5-7 days in the ground when the top 2-3 cm of soil is dry | Toxic to pets |
| Chrysanthemum 'Hillside Pink Sheffield' | Direct sun (at least 4-6 hours) | Every 5-7 days when the top 2-3 cm of soil is dry | Toxic to pets |
| Chrysanthemum 'Innocence' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chrysanthemum 'Mei-kyo' | Direct sun (at least 4-6 hours) | Every 5-7 days when the top 2-3 cm of soil is dry | Toxic to pets |
| Chrysanthemum 'Pennine Alfie' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, every 5-7 days in the growing season | Toxic to pets |
| Chrysanthemum 'Ruby Mound' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Chrysanthemum 'Rumpelstiltskin' | Direct sun (at least 4-6 hours) | Every 5-7 days, allowing the top 2 cm to dry between waterings | Toxic to pets |
| Chrysanthemum 'Ryan's Daisy' | Direct sun (at least 4-6 hours) | Every 5-7 days; increase to every 3-4 days in containers during hot spells | Toxic to pets |
| Chrysanthemum 'Salmon Allouise' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chrysanthemum 'Snowdon' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Chrysanthemum 'Time Piece' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chrysanthemum 'Will's Wonderful' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, approximately every 5-7 days | Toxic to pets |
| Chrysanthemum 'Yellow John Wingfield' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chrysanthemum 'Zeal Bronze' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Chusan Palm | Bright indirect light (just back from a sunny window) | Weekly in summer, monthly in winter | Pet-safe |
| Cigarette Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn through early spring; none or near-none in summer | Pet-safe |
| Cilician Colchicum | Direct sun (at least 4-6 hours) | Rely on natural rainfall during growth; keep dry in summer dormancy (June–August) | Toxic to pets |
| Cilician Fir | Direct sun (at least 4-6 hours) | Moderate; drought-tolerant once established | Pet-safe |
| Cilician Meadow Saffron | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry between waterings, roughly every 14-21 days in active growth | Toxic to pets |
| Cilician Winter Aconite | Medium indirect light (a couple of metres from a window) | Moist during late winter and spring growth; dry to moderate when dormant | Toxic to pets |
| Cinco de Mayo Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week through the growing season, more in heat | Pet-safe |
| Cinderella Miniature Rose | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water when the top 2-3 cm is dry, roughly twice weekly and more in heat | Pet-safe |
| Cinnamon Fern | Medium indirect light (a couple of metres from a window) | 2-3 times per week; keep consistently moist | Pet-safe |
| Cinnamon Fern | Low light (north window or shaded room) | Keep consistently moist to wet; water whenever the surface begins to dry, often every 3-5 days | Mildly toxic to pets |
| Cistus-Flowered Sundew | Direct sun (at least 4-6 hours) | Water regularly via the tray method throughout autumn–spring active growth; cease watering entirely from late spring through summer dormancy. | Pet-safe |
| Clara Fan Palm | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is completely dry, roughly every 14-21 days in summer | Pet-safe |
| Claret Cup Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; very little to none in winter | Mildly toxic to pets |
| Clarke's Cranesbill | Bright indirect light (just back from a sunny window) | Regularly during establishment; once established, once a week in dry periods | Pet-safe |
| Clasping Sage | Bright indirect light (just back from a sunny window) | Weekly to fortnightly | Pet-safe |
| Claw Sage | Direct sun (at least 4-6 hours) | Water when the top 3–5 cm of soil feels dry | Pet-safe |
| Cleft Antegibbaeum | Direct sun (at least 4-6 hours) | When the leaves begin to wrinkle slightly, roughly every 14-21 days in the growing season (autumn-spring); almost none in summer dormancy | Mildly toxic to pets |
| Cleistocactus baumannii | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly weekly in summer; sparingly in winter | Pet-safe |
| Clematis | Direct sun (at least 4-6 hours) | Keep evenly moist; water newly planted and container clematis frequently | Toxic to pets |
| Clematis 'Bill MacKenzie' | Direct sun (at least 4-6 hours) | Deeply about once a week while growing; less once established | Toxic to pets |
| Clematis 'Comtesse de Bouchaud' | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week in the growing season; more in heat or sandy soil | Toxic to pets |
| Clematis 'Doctor Ruppel' | Direct sun (at least 4-6 hours) | Deeply once or twice a week during the growing season; reduce in autumn and winter | Toxic to pets |
| Clematis 'Dr. Ruppel' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Clematis 'Duchess of Edinburgh' | Bright indirect light (just back from a sunny window) | Once or twice a week during the growing season | Toxic to pets |
| Clematis 'Ernest Markham' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about weekly in summer | Toxic to pets |
| Clematis 'Etoile Violette' | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week in the growing season | Toxic to pets |
| Clematis 'Fireworks' | Direct sun (at least 4-6 hours) | Once or twice a week in the growing season; reduce in autumn | Toxic to pets |
| Clematis 'General Sikorski' | Direct sun (at least 4-6 hours) | Once or twice a week during the growing season | Toxic to pets |
| Clematis 'H.F. Young' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil or compost is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Clematis 'Hagley Hybrid' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, about weekly in the growing season | Toxic to pets |
| Clematis 'Henryi' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, about weekly in summer | Toxic to pets |
| Clematis 'Jackmanii' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water deeply once or twice weekly in dry weather | Toxic to pets |
| Clematis 'Lasurstern' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil or compost is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Clematis 'Miss Bateman' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, about weekly in the growing season | Toxic to pets |
| Clematis 'Mrs N. Thompson' | Direct sun (at least 4-6 hours) | Once or twice a week during the growing season; reduce in cooler months | Toxic to pets |
| Clematis 'Multi Blue' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Clematis 'Nelly Moser' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply once or twice a week in dry spells | Toxic to pets |
| Clematis 'Niobe' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about weekly in summer | Toxic to pets |
| Clematis 'Perle d'Azur' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 5-7 days during active growth | Toxic to pets |
| Clematis 'Piilu' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Clematis 'Polish Spirit' | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week through the growing season | Toxic to pets |
| Clematis 'Rebecca' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Clematis 'Rouge Cardinal' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Clematis 'Rubens' | Direct sun (at least 4-6 hours) | Once or twice a week during dry spells, especially the first two seasons | Toxic to pets |
| Clematis 'The President' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply once or twice a week in dry spells | Toxic to pets |
| Clematis 'Ville de Lyon' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly weekly in the growing season | Toxic to pets |
| Clematis 'Warszawska Nike' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about weekly in summer | Toxic to pets |
| Clematis 'Westerplatte' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Clematis armandii | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly weekly in the growing season | Toxic to pets |
| Clematis florida 'Sieboldii' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Clematis integrifolia | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week through the growing season | Toxic to pets |
| Clematis montana | Direct sun (at least 4-6 hours) | Water regularly while establishing; mature plants are fairly drought-tolerant | Toxic to pets |
| Clematis montana 'Grandiflora' | Direct sun (at least 4-6 hours) | Once or twice a week while establishing; drought-tolerant once mature | Toxic to pets |
| Clematis recta | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week in the growing season | Toxic to pets |
| Clematis tangutica | Direct sun (at least 4-6 hours) | Deeply about once a week in the growing season; less once established | Toxic to pets |
| Clematis viticella | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week through the growing season | Toxic to pets |
| Clethra alnifolia | Bright indirect light (just back from a sunny window) | Keep soil moist; water weekly or more in dry weather, tolerant of wet ground | Mildly toxic to pets |
| Clethra alnifolia 'Hummingbird' | Bright indirect light (just back from a sunny window) | Keep soil moist; water weekly or more in dry weather, tolerant of wet ground | Mildly toxic to pets |
| Clethra alnifolia 'Ruby Spice' | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water deeply 1-2 times weekly in the first two seasons and during drought | Mildly toxic to pets |
| Clethra barbinervis | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water deeply weekly in the first two seasons and during dry spells | Mildly toxic to pets |
| Cleveland Sage | Direct sun (at least 4-6 hours) | Very infrequent after establishment — once monthly or less in summer | Pet-safe |
| Cliff Brake Fern | Bright indirect light (just back from a sunny window) | Allow the top half of the soil to dry out between waterings, roughly every 10-14 days | Mildly toxic to pets |
| Cliff Cotyledon | Bright indirect light (just back from a sunny window) | Every 10–14 days in summer, every 3–4 weeks in winter | Toxic to pets |
| Cliff Cotyledon | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, approximately every 14 days in summer | Toxic to pets |
| Cliff Date Palm | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; every 4–6 weeks in winter | Mildly toxic to pets |
| Cliff Date Palm | Direct sun (at least 4-6 hours) | Deeply every 7-10 days while establishing, then moderate | Pet-safe |
| Cliff Date Palm | Direct sun (at least 4-6 hours) | Water when the top 4-5 cm of soil is dry, roughly every 10-14 days | Pet-safe |
| Cliff Holly Fern | Low light (north window or shaded room) | Every 7–14 days; allow top half of soil to dry between waterings | Pet-safe |
| Climbing Aloe | Direct sun (at least 4-6 hours) | When the top few cm dry out, every 1-2 weeks in growth | Toxic to pets |
| Climbing Fetterbush | Medium indirect light (a couple of metres from a window) | Frequent; keep consistently moist to wet | Toxic to pets |
| Climbing Hydrangea | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply weekly in the first 2-3 years and during dry spells | Toxic to pets |
| Climbing Iceberg Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, more during heat | Pet-safe |
| Climbing Onion | Bright indirect light (just back from a sunny window) | Every 1–2 weeks while vining; withhold water during dry-season dormancy | Toxic to pets |
| Climbing Sundew | Bright indirect light (just back from a sunny window) | Tray method autumn–spring; bone dry summer dormancy | Mildly toxic to pets |
| Clivia 'Belgian Hybrid' | Medium indirect light (a couple of metres from a window) | Water when the top few cm are dry in growth; keep nearly dry through the winter rest | Toxic to pets |
| Clivia 'Doris Joy' | Bright indirect light (just back from a sunny window) | When the top few cm are dry in growth (every 7-14 days); much less in the winter rest | Toxic to pets |
| Cloth of Gold Saxifrage | Medium indirect light (a couple of metres from a window) | Every 5–7 days; reduce in winter | Pet-safe |
| Cloud Liveforever | Direct sun (at least 4-6 hours) | Every 1–2 weeks in cool season (October–April); completely withheld June–September | Pet-safe |
| Cloud Nine Dogwood | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce in winter | Mildly toxic to pets |
| Clustered bellflower | Direct sun (at least 4-6 hours) | Weekly during dry spells; moderate water needs | Pet-safe |
| Clustered Dendrobium | Bright indirect light (just back from a sunny window) | Every 5-7 days in summer; reduce sharply to monthly or less in winter | Pet-safe |
| Clustered Dunce Cap | Direct sun (at least 4-6 hours) | Weekly to fortnightly in active growth (spring–autumn); minimal in winter dormancy | Pet-safe |
| Clustered Sanicle | Low light (north window or shaded room) | Every 1–2 weeks; maintain consistent moisture, never waterlogged | Mildly toxic to pets |
| Clustered Silver Skin | Direct sun (at least 4-6 hours) | Every 2–4 weeks during autumn–early winter growth; minimal in spring; completely withheld in summer | Pet-safe |
| Clustered Specklinia | Bright indirect light (just back from a sunny window) | Every 2-3 days; keep medium consistently moist | Pet-safe |
| Coast Redwood Bonsai | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil starts to dry, often daily in warm weather | Mildly toxic to pets |
| Coast Rock Cress | Direct sun (at least 4-6 hours) | Weekly in the growing season; reduce to monthly or less when summer-dormant | Pet-safe |
| Coastal Leucothoe | Medium indirect light (a couple of metres from a window) | Regular; keep evenly moist | Toxic to pets |
| Cob Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; virtually none in winter | Pet-safe |
| Cobaea scandens | Direct sun (at least 4-6 hours) | Keep evenly moist through the growing season; water containers regularly | Mildly toxic to pets |
| Cobweb Houseleek | Direct sun (at least 4-6 hours) | When soil is fully dry, every 10-14 days in growth; sparingly in winter | Pet-safe |
| Cocoon Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks during active growth (spring and autumn); once a month in summer and winter | Toxic to pets |
| Coelogyne cristata | Bright indirect light (just back from a sunny window) | Every 4-7 days in growth; sparingly during the winter rest | Pet-safe |
| Coelogyne flaccida | Bright indirect light (just back from a sunny window) | Every 4-7 days in growth; reduced over winter | Pet-safe |
| Coelogyne nitida | Bright indirect light (just back from a sunny window) | Water 2-3 times weekly in growth; reduce to roughly weekly in the cool winter rest | Mildly toxic to pets |
| Cole's Prostrate Hemlock | Medium indirect light (a couple of metres from a window) | Every 1–2 weeks; do not allow soil to dry out | Pet-safe |
| Colombian Zamia | Bright indirect light (just back from a sunny window) | Every 10–21 days; reduce in winter when cold | Toxic to pets |
| Coloratus Euonymus | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Columbia Lewisia | Bright indirect light (just back from a sunny window) | Moderate; reduce in late summer and winter | Mildly toxic to pets |
| Columbine | Medium indirect light (a couple of metres from a window) | Moderate; water during dry spells | Toxic to pets |
| Column Aubrieta | Direct sun (at least 4-6 hours) | Weekly during spring growth; very sparingly in summer | Pet-safe |
| Column Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; once a month or less in winter | Mildly toxic to pets |
| Columnar English Oak | Direct sun (at least 4-6 hours) | Regular deep watering in the first 3-5 years; established trees are largely drought-tolerant | Mildly toxic to pets |
| Columnar Italian Cypress | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 14-21 days once established | Mildly toxic to pets |
| Comb Cycad | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; every 3–5 weeks in autumn and winter | Toxic to pets |
| Comfrey-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Moderate during the growing season; reduce significantly in winter. Established plants in the ground need watering only during extended dry spells. | Mildly toxic to pets |
| Common Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (soil should be consistently moist but not waterlogged) | Toxic to pets |
| Common Bamboo | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week; daily in hot or dry conditions | Pet-safe |
| Common Bird's-foot Trefoil | Direct sun (at least 4-6 hours) | Low once established | Mildly toxic to pets |
| Common Bistort | Medium indirect light (a couple of metres from a window) | Frequently — keep soil consistently moist | Mildly toxic to pets |
| Common Blanket Flower | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is fully dry, roughly every 10-14 days; very infrequent once established | Mildly toxic to pets |
| Common blue violet | Medium indirect light (a couple of metres from a window) | Every 5–10 days; tolerates wet soil | Pet-safe |
| Common box | Medium indirect light (a couple of metres from a window) | Weekly during establishment; monthly once established in the ground | Toxic to pets |
| Common Boxwood 'Suffruticosa' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly weekly in summer | Toxic to pets |
| Common Broomrape | Direct sun (at least 4-6 hours) | Wholly dependent on host plant via haustorial connection | Mildly toxic to pets |
| Common Bugle | Medium indirect light (a couple of metres from a window) | Moderate; consistent moisture preferred | Mildly toxic to pets |
| Common Butterwort | Bright indirect light (just back from a sunny window) | Keep permanently wet in the growing season; stand in shallow pure water | Mildly toxic to pets |
| Common Candelabra Tylecodon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in winter growing season; withhold almost entirely in summer dormancy | Toxic to pets |
| Common Club-rush | Direct sun (at least 4-6 hours) | Permanently aquatic; plant at 30–150 cm (12–60 in) water depth | Pet-safe |
| Common Cordgrass | Direct sun (at least 4-6 hours) | Permanent wetland/tidal immersion | Pet-safe |
| Common Cow-wheat | Medium indirect light (a couple of metres from a window) | Moderate; keep soil evenly moist but never waterlogged | Mildly toxic to pets |
| common dogwood | Bright indirect light (just back from a sunny window) | Weekly in first season; largely self-sufficient once established | Mildly toxic to pets |
| Common Foxglove | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water weekly in dry spells | Toxic to pets |
| Common Foxtail Cactus | Direct sun (at least 4-6 hours) | When the potting mix is completely dry, roughly every 10-21 days in summer; very sparingly in winter | Pet-safe |
| Common Garden Tulip | Direct sun (at least 4-6 hours) | Naturally rainfall-dependent; water sparingly if dry after planting | Toxic to pets |
| Common Gladiolus | Direct sun (at least 4-6 hours) | Once or twice per week during active growth | Toxic to pets |
| Common Grape Hyacinth | Bright indirect light (just back from a sunny window) | Weekly in spring during active growth; dry during summer dormancy | Mildly toxic to pets |
| Common Grape Hyacinth | Direct sun (at least 4-6 hours) | Rainfall typically sufficient; water lightly once per week only in very dry springs | Toxic to pets |
| Common Heather | Direct sun (at least 4-6 hours) | Water weekly in dry spells for the first two seasons; established plants are moderately drought-tolerant | Pet-safe |
| Common Hepatica | Medium indirect light (a couple of metres from a window) | Every 5–7 days in the growing season; reduce in summer dormancy | Mildly toxic to pets |
| Common hollyhock | Direct sun (at least 4-6 hours) | Weekly when established; more in heat or drought | Mildly toxic to pets |
| Common Hyacinth | Direct sun (at least 4-6 hours) | Weekly when in active growth; withhold water during summer dormancy | Toxic to pets |
| Common Jasmine | Direct sun (at least 4-6 hours) | Water regularly while establishing and in dry spells; water when the top few cm of soil dries | Pet-safe |
| Common Lilac | Direct sun (at least 4-6 hours) | Deeply once a week in the first year, then only in drought | Mildly toxic to pets |
| Common Lime | Direct sun (at least 4-6 hours) | Regular in first 2–3 years; occasional once established | Pet-safe |
| Common Maidenhair Fern | Medium indirect light (a couple of metres from a window) | Every 2–4 days; keep soil evenly moist | Pet-safe |
| Common Mallow | Direct sun (at least 4-6 hours) | Low once established | Pet-safe |
| Common manzanita | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established — water sparingly in summer | Mildly toxic to pets |
| Common Milkweed | Direct sun (at least 4-6 hours) | Moderate; weekly when establishing, drought-tolerant once established | Toxic to pets |
| Common Milkwort | Direct sun (at least 4-6 hours) | Rarely; drought-tolerant once established | Mildly toxic to pets |
| Common Nardoo | Bright indirect light (just back from a sunny window) | Keep permanently in water or wet mud | Toxic to pets |
| Common peony | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce after bloom | Mildly toxic to pets |
| Common Polypody | Medium indirect light (a couple of metres from a window) | Every 10–14 days; tolerates extended dry periods once established | Pet-safe |
| Common Poppy | Direct sun (at least 4-6 hours) | Low once established; water seedlings until established | Toxic to pets |
| Common Quaking Grass | Direct sun (at least 4-6 hours) | Rarely; drought-tolerant once established | Pet-safe |
| Common Rhododendron | Bright indirect light (just back from a sunny window) | Weekly during dry periods; established plants are tolerant but flower best with consistent moisture | Toxic to pets |
| Common Rush | Direct sun (at least 4-6 hours) | Permanently wet or standing water to 15 cm (6 in) deep | Pet-safe |
| Common Saltmarsh Grass | Direct sun (at least 4-6 hours) | Tidal — periodic saltwater flooding | Pet-safe |
| Common Snowdrop | Medium indirect light (a couple of metres from a window) | Naturally moisture-retentive soil; supplemental watering in dry spells during growth | Toxic to pets |
| Common Spike-rush | Direct sun (at least 4-6 hours) | Permanently aquatic to waterlogged; plant at 0–30 cm (0–12 in) water depth | Pet-safe |
| Common Spotted Orchid | Bright indirect light (just back from a sunny window) | Relies on natural rainfall | Mildly toxic to pets |
| Common Star of Bethlehem | Direct sun (at least 4-6 hours) | Low; self-sufficient in a UK garden once established | Toxic to pets |
| Common Stork's Bill | Direct sun (at least 4-6 hours) | Naturally rain-fed; no supplemental watering needed for wild or meadow plantings | Mildly toxic to pets |
| Common teasel | Direct sun (at least 4-6 hours) | Rarely needs supplemental watering once established; water seedlings regularly | Pet-safe |
| Common Water Hyacinth | Direct sun (at least 4-6 hours) | Free-floating aquatic — roots permanently submerged in open water | Pet-safe |
| Common Water Starwort | Medium indirect light (a couple of metres from a window) | Permanently submerged or marginal | Pet-safe |
| Common Witch Hazel | Medium indirect light (a couple of metres from a window) | Roughly every 7-10 days during establishment; established plants need watering every 10-14 days in dry periods | Mildly toxic to pets |
| Common Witch Hazel 'Arnold Promise' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; keep evenly moist in the first years and during droughts | Mildly toxic to pets |
| Compact Angraecum | Bright indirect light (just back from a sunny window) | Every 2–4 days in summer; every 7–14 days in winter | Pet-safe |
| Compact Ice Plant | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in the growing season; monthly or less in winter | Mildly toxic to pets |
| Compact Japanese Umbrella Pine | Bright indirect light (just back from a sunny window) | Weekly during growing season; reduce in winter | Pet-safe |
| Compact White Fir | Direct sun (at least 4-6 hours) | Every 10-14 days during the first two years; drought-tolerant once established | Mildly toxic to pets |
| Compacta Holly | Direct sun (at least 4-6 hours) | Weekly deep watering when establishing, then every 7-14 days in dry periods | Toxic to pets |
| Compass Plant | Direct sun (at least 4-6 hours) | Every 2-4 weeks once established | Pet-safe |
| Compassion Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly when young; established plants when the top 5 cm of soil is dry | Pet-safe |
| Compton's Gibbaeum | Direct sun (at least 4-6 hours) | Every 2–4 weeks in autumn and spring (active growth); withheld or near-dry in summer and reduced in winter | Pet-safe |
| Compton's Living Stone | Direct sun (at least 4-6 hours) | Sparingly every 2-4 weeks in summer; none from late autumn through winter leaf renewal | Pet-safe |
| Coneflower 'White Swan' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; established plants are drought-tolerant once settled after the first season | Mildly toxic to pets |
| Confused Huernia | Bright indirect light (just back from a sunny window) | Every 14–21 days during active growth (spring–autumn); once monthly or less in winter | Pet-safe |
| Conica Jean's Dilly Spruce | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply weekly in the first two seasons, then during dry spells | Mildly toxic to pets |
| Conophytum Calculus | Bright indirect light (just back from a sunny window) | During autumn-to-spring growth, every 1-2 weeks; none through summer dormancy | Mildly toxic to pets |
| Conophytum ficiforme | Bright indirect light (just back from a sunny window) | Lightly in autumn and winter when in growth; keep dry through summer dormancy | Mildly toxic to pets |
| Conophytum Minutum | Bright indirect light (just back from a sunny window) | During the cool-season growth (autumn to spring), every 1-2 weeks; kept dry through summer dormancy | Mildly toxic to pets |
| Conophytum Obcordellum | Bright indirect light (just back from a sunny window) | Seasonally; water in autumn and winter growth, keep dry through summer dormancy | Mildly toxic to pets |
| Conophytum Pageae | Bright indirect light (just back from a sunny window) | Through autumn-to-spring growth, every 1-2 weeks; withheld over summer dormancy | Mildly toxic to pets |
| Conophytum Pellucidum | Bright indirect light (just back from a sunny window) | During autumn-to-spring growth, every 1-2 weeks; withheld over summer dormancy | Mildly toxic to pets |
| Conophytum Uviforme | Bright indirect light (just back from a sunny window) | Only during the cool autumn-to-spring growing season, roughly every 10-14 days when soil is dry; kept dry in summer | Mildly toxic to pets |
| Conophytum wettsteinii | Bright indirect light (just back from a sunny window) | Lightly in autumn and winter during growth; keep dry through summer dormancy | Mildly toxic to pets |
| Constance Spry Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while establishing; mature plants when the top few centimetres of soil dry | Pet-safe |
| Constricted Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in summer heat; every 2–3 days in cooler months | Pet-safe |
| Copal Bursera | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; once or twice monthly in winter | Mildly toxic to pets |
| Copiapoa cinerea | Direct sun (at least 4-6 hours) | Sparingly when fully dry in summer, roughly every 2-3 weeks; little to none in winter | Pet-safe |
| Copiapoa humilis | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer; keep bone-dry in winter | Pet-safe |
| Copiapoa hypogaea | Direct sun (at least 4-6 hours) | Sparingly when fully dry in summer, roughly every 2-3 weeks; little to none in winter | Pet-safe |
| Copiapoa krainziana | Direct sun (at least 4-6 hours) | When soil is completely dry, about every 2-3 weeks in summer; keep dry in winter | Pet-safe |
| Copper Iris | Direct sun (at least 4-6 hours) | Continuously moist to waterlogged | Mildly toxic to pets |
| Copper Rain Lily | Direct sun (at least 4-6 hours) | Low to moderate; rain-triggered | Toxic to pets |
| Coquimbo Copiapoa | Direct sun (at least 4-6 hours) | Every 14-21 days in summer; once a month or less in winter | Pet-safe |
| Coral Aloe | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer, sparingly in winter | Toxic to pets |
| Coral Bark Japanese Maple 'Sango-kaku' | Bright indirect light (just back from a sunny window) | Once or twice weekly through the growing season | Pet-safe |
| Coral bells | Medium indirect light (a couple of metres from a window) | Weekly during active growth; reduce in autumn and winter | Pet-safe |
| Coral Bells 'Caramel' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, around weekly in growth; more in heat and for containers | Pet-safe |
| Coral Bells 'Caramel' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil feels dry, roughly every 5-7 days during active growth | Pet-safe |
| Coral Bells 'Electra' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Pet-safe |
| Coral Bells 'Lime Rickey' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil feels dry, roughly every 5-7 days during active growth | Pet-safe |
| Coral Bells 'Obsidian' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly in growth; more in heat and for container plants | Pet-safe |
| Coral Bells 'Obsidian' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, approximately every 5-7 days during the growing season | Pet-safe |
| Coral Bells 'Palace Purple' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly in growth; more in heat and for container plants | Pet-safe |
| Coral Bells 'Palace Purple' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Pet-safe |
| Cordyline australis | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in growth | Toxic to pets |
| Coreopsis 'Jethro Tull' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days once established | Pet-safe |
| Coreopsis 'Limerock Ruby' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Mercury Rising' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Moonbeam' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days; very drought-tolerant once established | Pet-safe |
| Coreopsis 'Route 66' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Sienna Sunset' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Sunkiss' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Coreopsis 'Sunray' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Uptick Gold and Bronze' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Coreopsis 'Zagreb' | Direct sun (at least 4-6 hours) | Water to establish, then only in extended drought; drought-tolerant once settled | Pet-safe |
| Coreopsis grandiflora 'Early Sunrise' | Direct sun (at least 4-6 hours) | Water to establish, then only during drought; drought-tolerant once settled | Pet-safe |
| Coris-Leaved St John's Wort | Direct sun (at least 4-6 hours) | Low — water sparingly once established | Toxic to pets |
| Cork-Stemmed Passionflower | Direct sun (at least 4-6 hours) | Once or twice a week until established; less once mature | Pet-safe |
| Corkscrew Rush | Bright indirect light (just back from a sunny window) | Keep soil permanently wet; top up the water saucer every 3–5 days | Pet-safe |
| Corky-Stemmed Passion Flower | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer | Mildly toxic to pets |
| Cornelia Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, increasing in heat | Pet-safe |
| Cornish Heath Mrs D.F. Maxwell | Direct sun (at least 4-6 hours) | Water weekly during dry spells, especially in the first two years | Pet-safe |
| Cornus kousa 'Miss Satomi' | Direct sun (at least 4-6 hours) | Water deeply weekly while establishing; supplement in dry spells | Pet-safe |
| Corrugated Sage | Bright indirect light (just back from a sunny window) | Weekly | Mildly toxic to pets |
| Corsican Heron's Bill | Direct sun (at least 4-6 hours) | Low — allow soil to dry between waterings | Mildly toxic to pets |
| Cosson's Germander | Direct sun (at least 4-6 hours) | Sparingly every 2–3 weeks in summer; minimal to none in winter | Mildly toxic to pets |
| Cotinus coggygria 'Golden Spirit' | Direct sun (at least 4-6 hours) | Weekly while establishing; sparingly once mature | Mildly toxic to pets |
| Cotinus coggygria 'Grace' | Direct sun (at least 4-6 hours) | Weekly while establishing; rarely thereafter once rooted | Mildly toxic to pets |
| Cotinus obovatus | Direct sun (at least 4-6 hours) | Weekly during establishment; very rarely once mature | Mildly toxic to pets |
| Cotoneaster Bonsai | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil is dry, roughly every 1-3 days in summer | Mildly toxic to pets |
| Cotoneaster microphyllus | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil is dry, roughly every 1-3 days in summer | Mildly toxic to pets |
| Cottontop Cactus | Direct sun (at least 4-6 hours) | Every 3–5 weeks in summer; completely dry in winter | Mildly toxic to pets |
| Cotyledon Eliseae | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 10-14 days in growth | Toxic to pets |
| Cotyledon Orbiculata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Toxic to pets |
| Cotyledon Papillaris | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in growth | Toxic to pets |
| Cow Parsley | Medium indirect light (a couple of metres from a window) | Moderate; water during dry spells in the first season | Mildly toxic to pets |
| Cowslip Orchid | Bright indirect light (just back from a sunny window) | Lightly during autumn to spring growth; completely dry during summer dormancy | Pet-safe |
| Crabapple 'Evereste' | Direct sun (at least 4-6 hours) | Weekly during establishment and dry spells | Toxic to pets |
| Crabapple 'Hanagasa' | Direct sun (at least 4-6 hours) | When the top 2-3 cm is dry, frequently daily in summer and less in dormancy | Toxic to pets |
| Crabapple 'John Downie' | Direct sun (at least 4-6 hours) | Weekly while young and in summer drought | Toxic to pets |
| Crabapple Bonsai | Direct sun (at least 4-6 hours) | When the surface soil starts to dry, often once or twice daily in summer | Toxic to pets |
| Crane's Bill Stork's Bill | Direct sun (at least 4-6 hours) | Water lightly; allow the soil surface to dry between waterings | Mildly toxic to pets |
| Crassula Hemisphaerica | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is fully dry, roughly every 10-14 days in growth; less in summer rest | Toxic to pets |
| Crassula Nudicaulis | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in growth | Toxic to pets |
| Crassula Pyramidalis | Bright indirect light (just back from a sunny window) | Sparingly, only when soil is bone dry, roughly every 2-3 weeks in growth; nearly dry over summer rest | Toxic to pets |
| Crataegus laevigata 'Paul's Scarlet' | Direct sun (at least 4-6 hours) | Water weekly for the first two seasons; established trees are very drought-tolerant | Pet-safe |
| Crataegus persimilis 'Prunifolia' | Direct sun (at least 4-6 hours) | Water weekly for the first two seasons; established trees are drought-tolerant | Pet-safe |
| Crater Argyroderma | Direct sun (at least 4-6 hours) | Every 3–5 weeks in the autumn–winter growing period; none from May through August | Pet-safe |
| Cream Wild Indigo | Direct sun (at least 4-6 hours) | Low; water weekly in first season only | Toxic to pets |
| Creeping Blue Blossom | Direct sun (at least 4-6 hours) | Every 7-10 days during the first growing season; established plants are very drought-tolerant and need supplemental watering only in prolonged dry summers | Mildly toxic to pets |
| Creeping Comfrey | Low light (north window or shaded room) | Every 7–14 days; largely self-sufficient once established | Mildly toxic to pets |
| Creeping Gaultheria | Medium indirect light (a couple of metres from a window) | Regularly; soil must not dry out | Toxic to pets |
| Creeping Globularia | Direct sun (at least 4-6 hours) | Every 14 days during active growth; virtually none in winter. | Mildly toxic to pets |
| Creeping Mazus | Bright indirect light (just back from a sunny window) | Every 3–5 days; prefers consistently moist soil | Mildly toxic to pets |
| Creeping New Zealand Cranesbill | Direct sun (at least 4-6 hours) | Every 7–10 days in the growing season; minimal in winter | Pet-safe |
| Creeping Phlox | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2 weeks once established | Mildly toxic to pets |
| Creeping Phlox 'Blue Ridge' | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Creeping Sage | Bright indirect light (just back from a sunny window) | Weekly during the growing season | Pet-safe |
| Creeping snowberry | Medium indirect light (a couple of metres from a window) | Regular; keep moist | Mildly toxic to pets |
| Creeping Speedwell | Bright indirect light (just back from a sunny window) | Moderate; water when the top 2–3 cm of soil begins to dry | Pet-safe |
| Creeping Woodland Phlox | Medium indirect light (a couple of metres from a window) | Weekly; maintain consistent moisture | Mildly toxic to pets |
| Crenate Orchid Cactus | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-14 days in the growing season; reduce to once every 3-4 weeks in winter | Pet-safe |
| Crested Bracken | Medium indirect light (a couple of metres from a window) | every 1-2 weeks once established | Toxic to pets |
| Crested Christmas Fern | Low light (north window or shaded room) | Every 7–10 days; allow top 2–3 cm to dry between waterings | Pet-safe |
| Crested Gentian | Direct sun (at least 4-6 hours) | Regular; keep soil consistently moist during the growing season | Mildly toxic to pets |
| Crested Iris | Medium indirect light (a couple of metres from a window) | Moderate — keep evenly moist | Toxic to pets |
| Crested Phlomis | Direct sun (at least 4-6 hours) | Once every 2–3 weeks in summer, barely at all in winter | Mildly toxic to pets |
| Crested Vanda | Bright indirect light (just back from a sunny window) | Daily to every other day in summer; every 3-5 days in winter | Pet-safe |
| Crested Wood Fern | Medium indirect light (a couple of metres from a window) | Keep soil constantly moist; check every 3-5 days | Mildly toxic to pets |
| Cretan Arum | Direct sun (at least 4-6 hours) | Moderate during autumn–spring active growth; completely dry in summer | Toxic to pets |
| Cretan Date Palm | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly or less in winter | Mildly toxic to pets |
| Cretan Date Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Crimson and Gold quince | Bright indirect light (just back from a sunny window) | Weekly when newly planted; established plants largely rain-fed in temperate climates | Mildly toxic to pets |
| Crimson Cestrum | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce to every 10–14 days in winter | Toxic to pets |
| Crimson Flag Lily | Direct sun (at least 4-6 hours) | Consistently moist throughout the growing season | Toxic to pets |
| Crimson Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic — crown submerged 15–50 cm (6–20 in) below water surface | Pet-safe |
| Crimson-Spot Rock Rose | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; weekly in the first growing season | Mildly toxic to pets |
| Crippsii Hinoki Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days while establishing, then when the top few cm of soil dry | Mildly toxic to pets |
| Crispum Hart's Tongue Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days; keep evenly moist | Pet-safe |
| Crocosmia × crocosmiiflora 'Emily McKenzie' | Direct sun (at least 4-6 hours) | Weekly during growth and flowering in dry weather; ease off as foliage dies back | Mildly toxic to pets |
| Crocosmia × crocosmiiflora 'Jackanapes' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; water through dry spells in the growing season | Mildly toxic to pets |
| Crocosmia × crocosmiiflora 'Lucifer' | Direct sun (at least 4-6 hours) | Weekly during active growth and flowering in dry spells; reduce after foliage dies back | Mildly toxic to pets |
| Crocosmia × crocosmiiflora 'Solfatare' | Direct sun (at least 4-6 hours) | Weekly during growth and flowering in dry spells; reduce as foliage dies back | Mildly toxic to pets |
| Crocosmia masoniorum | Direct sun (at least 4-6 hours) | Weekly during growth and flowering in dry weather; taper off as foliage dies back | Mildly toxic to pets |
| Crocus | Direct sun (at least 4-6 hours) | Natural rainfall | Mildly toxic to pets |
| Crocus 'Jeanne d'Arc' | Direct sun (at least 4-6 hours) | Rely on natural rainfall; water only during a dry autumn after planting or a droughty spring | Mildly toxic to pets |
| Crocus 'Pickwick' | Direct sun (at least 4-6 hours) | Depend on rainfall; supplemental water only during a dry spell right after autumn planting or active spring growth | Mildly toxic to pets |
| Crocus chrysanthus 'Cream Beauty' | Direct sun (at least 4-6 hours) | Rely on rainfall; water only during a dry establishment period after planting or a droughty spring | Mildly toxic to pets |
| Crocus tommasinianus 'Ruby Giant' | Direct sun (at least 4-6 hours) | Rainfall-reliant; water only briefly during a dry autumn establishment or droughty early spring | Mildly toxic to pets |
| Cross Gentian | Bright indirect light (just back from a sunny window) | Water regularly until established; drought-tolerant thereafter | Mildly toxic to pets |
| Cross Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once a month or less in winter | Pet-safe |
| Cross-leaved Heath Alba Mollis | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 5–7 days in dry spells | Pet-safe |
| Crossvine | Bright indirect light (just back from a sunny window) | Weekly when young; established plants are drought-tolerant | Mildly toxic to pets |
| Crosswort | Medium indirect light (a couple of metres from a window) | Low to moderate — rainfall sufficient in UK | Mildly toxic to pets |
| Crown Brodiaea | Direct sun (at least 4-6 hours) | Moderate during autumn-to-spring growth; completely dry from flowering through to early autumn | Mildly toxic to pets |
| Crown Fern | Medium indirect light (a couple of metres from a window) | 2-3 times per week in growing season; reduce in winter | Pet-safe |
| Crown Vetch | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Crystal Butterwort | Bright indirect light (just back from a sunny window) | Water lightly every 5–10 days during the carnivorous growing phase; allow to nearly dry between waterings in summer succulent-leaf phase | Pet-safe |
| Crystal Palace lobelia | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil is dry, typically every 2-3 days in summer | Toxic to pets |
| Crystal Palace Lobelia | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil feels dry, roughly every 3-5 days | Toxic to pets |
| Cuban Lily | Direct sun (at least 4-6 hours) | Moderate in autumn through spring; restrict in summer | Toxic to pets |
| Cuban Petticoat Palm | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in summer; every 3-5 weeks in winter | Pet-safe |
| Cuban Royal Palm | Direct sun (at least 4-6 hours) | Every 5–7 days when young; established trees weekly or rely on rainfall | Pet-safe |
| Cucumber Tree Magnolia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks when established; more frequently during active growth in summer | Pet-safe |
| Cunninghamia 'Glauca' | Direct sun (at least 4-6 hours) | Keep soil moist; water regularly while young, then deeply in dry spells once established | Mildly toxic to pets |
| Cup of gold vine | Direct sun (at least 4-6 hours) | Water to keep soil evenly moist during the growing season; reduce to occasional deep watering in winter | Toxic to pets |
| Cup Plant | Direct sun (at least 4-6 hours) | Keep soil moist; water deeply in dry spells, every 5-7 days | Mildly toxic to pets |
| Cupani sweet pea | Direct sun (at least 4-6 hours) | Every 3–5 days in warm growing conditions; adjust for rainfall | Toxic to pets |
| Curio Ficoides | Direct sun (at least 4-6 hours) | Water deeply only when the soil is fully dry, roughly every 2-3 weeks in summer and far less in winter | Toxic to pets |
| Curio Talinoides var. mandraliscae | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 10-14 days in growth | Toxic to pets |
| Curled Air Plant | Direct sun (at least 4-6 hours) | 2–4 times weekly in summer, weekly in winter | Pet-safe |
| Curly Oncidium | Bright indirect light (just back from a sunny window) | Every 5–7 days during growth; every 10–14 days during winter rest | Pet-safe |
| Curly Pondweed | Bright indirect light (just back from a sunny window) | Fully submerged; grows in 30 cm to 2 m of water | Pet-safe |
| Curly Waterweed | Bright indirect light (just back from a sunny window) | Fully submerged; ponds — no regular water changes needed; aquariums — 20-25% weekly | Mildly toxic to pets |
| Curly-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; weekly during the first growing season | Mildly toxic to pets |
| Curly-Wurly Rush | Bright indirect light (just back from a sunny window) | Constant — keep roots standing in shallow water or in permanently wet soil | Pet-safe |
| Curror's Cyphostemma | Direct sun (at least 4-6 hours) | Every 2–4 weeks in the growing season; once every 6–8 weeks or less in winter | Toxic to pets |
| Curved-Flower Sage | Bright indirect light (just back from a sunny window) | Regular, allowing surface to partially dry between waterings | Mildly toxic to pets |
| Cusick's Camas | Bright indirect light (just back from a sunny window) | Regular during autumn through spring growth; reduces naturally as foliage senesces in early summer | Mildly toxic to pets |
| Cut Eye-leaf | Direct sun (at least 4-6 hours) | Every 2-3 weeks in the autumn-spring growing season when the body shows light wrinkling; completely dry in summer | Mildly toxic to pets |
| Cut-Leaved Cranesbill | Direct sun (at least 4-6 hours) | Moderate; keep soil moist during spring and summer | Pet-safe |
| Cuthbertson's Dendrobium | Bright indirect light (just back from a sunny window) | When the medium surface begins to dry, roughly every 1-3 days | Pet-safe |
| Cutleaf Fleabane | Direct sun (at least 4-6 hours) | Every 10–14 days during active growth; very little in winter | Pet-safe |
| Cycas Panzhihuaensis | Direct sun (at least 4-6 hours) | Water when the top 4-5 cm of soil is dry, roughly every 1-2 weeks in growth | Toxic to pets |
| Cyclamen 'Victoria' | Bright indirect light (just back from a sunny window) | When the top of the compost feels dry, roughly every 5-7 days while in growth | Toxic to pets |
| Cylindric Arum | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil is dry during the growing season; cease watering during summer dormancy | Toxic to pets |
| Cymbidium 'Red Beauty' | Bright indirect light (just back from a sunny window) | Every 4-7 days in growth; every 10-14 days in winter | Pet-safe |
| Cymbidium 'Sarah Jean' | Bright indirect light (just back from a sunny window) | Keep evenly moist in growth, about every 5-7 days, drier in winter | Pet-safe |
| Cymbidium 'Showgirl' | Bright indirect light (just back from a sunny window) | Every 4-7 days in growth; every 10-14 days in winter | Pet-safe |
| Cymbidium devonianum | Bright indirect light (just back from a sunny window) | Every 5-7 days in growth; reduce to every 10-14 days in winter | Pet-safe |
| Cymbidium erythrostylum | Bright indirect light (just back from a sunny window) | Every 5-7 days in growth; every 10-14 days in winter | Pet-safe |
| Cymbidium tracyanum | Bright indirect light (just back from a sunny window) | Every 3-6 days in growth; keep evenly moist in summer | Pet-safe |
| Cyperus longus | Direct sun (at least 4-6 hours) | Keep the soil wet to saturated; grow in shallow water up to about 5-15 cm or in permanently boggy ground | Mildly toxic to pets |
| Cyperus Sedge | Bright indirect light (just back from a sunny window) | Permanently wet; shallow water up to 15 cm deep | Pet-safe |
| Cyperus-Like Sedge | Medium indirect light (a couple of metres from a window) | Permanent moisture; plant in standing water up to 15 cm deep | Pet-safe |
| Cyprus Cedar | Direct sun (at least 4-6 hours) | Infrequently; drought-tolerant once established | Mildly toxic to pets |
| Cyrtomium macrophyllum | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Cystopteris bulbifera | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water when the surface begins to dry, roughly every 3-6 days in growth | Mildly toxic to pets |
| Cystopteris fragilis | Medium indirect light (a couple of metres from a window) | Keep evenly moist while in growth, watering when the top 1-2 cm of soil dries, roughly every 4-7 days | Mildly toxic to pets |
| Daffodil | Direct sun (at least 4-6 hours) | Rely on rainfall in autumn-spring; keep dry in summer | Toxic to pets |
| Daffodil | Bright indirect light (just back from a sunny window) | Moderate during active growth (autumn–spring); dry during summer dormancy | Toxic to pets |
| Dagger-Leaf Rush | Bright indirect light (just back from a sunny window) | Frequent to constant — soil must remain moist to wet at all times | Pet-safe |
| Daghestan Sage | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Dahlia | Direct sun (at least 4-6 hours) | Twice weekly during active growth | Mildly toxic to pets |
| Dahlia 'Bishop of Dover' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil dries out, roughly every 3-5 days in warm weather | Mildly toxic to pets |
| Dahlia 'Bishop of Llandaff' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Bishop of Oxford' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil is dry, typically every 3-5 days in summer | Mildly toxic to pets |
| Dahlia 'Cafe au Lait' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Decorette Rose' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days; container plants may need daily watering in hot weather | Toxic to pets |
| Dahlia 'El Trasno' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil feels dry, approximately every 3-5 days in summer | Mildly toxic to pets |
| Dahlia 'Jazz' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Mingus Tina' | Direct sun (at least 4-6 hours) | Every 3-4 days during active growth, more frequently in hot weather | Toxic to pets |
| Dahlia 'Mrs Eileen' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Mystery Day' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Penhill Dark Monarch' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Purple Taiheijo' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Rip City' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Dahlia 'Soda Fountain' | Direct sun (at least 4-6 hours) | Every 3-4 days in warm weather; less in cool spells | Toxic to pets |
| Dalmatian Cranesbill | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; minimal in winter | Pet-safe |
| Dalstroem's Dragon Orchid | Medium indirect light (a couple of metres from a window) | Daily misting or watering; roots must remain continuously moist but never waterlogged | Pet-safe |
| Danford Iris | Direct sun (at least 4-6 hours) | Moderate in late winter and early spring; dry in summer | Toxic to pets |
| Daphne cneorum | Direct sun (at least 4-6 hours) | Water when the top few centimetres of soil are dry; keep evenly moist but sharply drained | Toxic to pets |
| Daphne laureola | Low light (north window or shaded room) | Weekly while establishing; rarely once established | Toxic to pets |
| Daphne mezereum | Bright indirect light (just back from a sunny window) | Water when the top few centimetres of soil are dry; keep evenly moist, never waterlogged | Toxic to pets |
| Daphne odora | Bright indirect light (just back from a sunny window) | Water when the top few centimetres of soil are dry; keep evenly moist, never soggy | Toxic to pets |
| Daphne odora 'Aureomarginata' | Bright indirect light (just back from a sunny window) | Water when the top few centimetres of soil are dry; keep evenly moist but never wet | Toxic to pets |
| Daphne x burkwoodii 'Carol Mackie' | Bright indirect light (just back from a sunny window) | Water when the top few centimetres of soil are dry; keep evenly moist, never waterlogged | Toxic to pets |
| Darcy's Sage | Direct sun (at least 4-6 hours) | Regular to moderate — allow soil surface to dry between waterings | Mildly toxic to pets |
| Dark Green Ceratozamia | Medium indirect light (a couple of metres from a window) | Weekly in summer; every 2–3 weeks in winter | Toxic to pets |
| Dark Pitcher Plant | Bright indirect light (just back from a sunny window) | Keep substrate evenly moist at all times | Mildly toxic to pets |
| Darley Dale Heath Furzey | Direct sun (at least 4-6 hours) | Water weekly in dry spells; reduce in winter unless the soil is very dry | Pet-safe |
| Darwin's barberry | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; drought-tolerant once established | Mildly toxic to pets |
| Darwin's Barberry | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Darwin's Slipper | Bright indirect light (just back from a sunny window) | Moderately — water when the top of the compost is barely dry | Mildly toxic to pets |
| Darwin's Slipper Plant | Bright indirect light (just back from a sunny window) | When the top of the growing medium dries slightly | Mildly toxic to pets |
| David viburnum | Bright indirect light (just back from a sunny window) | Once or twice weekly when establishing; monthly once mature | Mildly toxic to pets |
| Davidia involucrata | Bright indirect light (just back from a sunny window) | Weekly in dry spells, especially the first few years | Mildly toxic to pets |
| Davis's Masdevallia | Medium indirect light (a couple of metres from a window) | When the medium surface barely begins to dry, roughly every 3-5 days | Pet-safe |
| Dawn Redwood 'Gold Rush' | Direct sun (at least 4-6 hours) | When the surface soil starts to dry; keep consistently moist, every 5-10 days | Mildly toxic to pets |
| Dawn Redwood 'Ogon' | Direct sun (at least 4-6 hours) | When the topsoil begins to dry; keep evenly moist, every 5-10 days | Mildly toxic to pets |
| Dawn Redwood Bonsai | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil starts to dry, often daily or twice daily in summer | Mildly toxic to pets |
| Dawn viburnum | Bright indirect light (just back from a sunny window) | Weekly in the first two seasons; every 2–3 weeks once established | Mildly toxic to pets |
| Day-blooming Jasmine | Bright indirect light (just back from a sunny window) | Every 5–7 days; reduce in cooler or wet seasons | Toxic to pets |
| Daybreak Red Stripe Treasure Flower | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days | Pet-safe |
| Daylily 'Autumn Minaret' | Direct sun (at least 4-6 hours) | Every 7-14 days during active growth; minimal in winter dormancy | Toxic to pets |
| Daylily 'Bitsy' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season; reduce to once every 2-3 weeks as foliage dies back | Toxic to pets |
| Daylily 'Black-eyed Stella' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Bumble Bee' | Direct sun (at least 4-6 hours) | Every 7-10 days in active growth; every 2-3 weeks once dormant | Toxic to pets |
| Daylily 'Catherine Woodbery' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season; every 2-3 weeks during dormancy | Toxic to pets |
| Daylily 'Chicago Apache' | Direct sun (at least 4-6 hours) | Roughly every 7-10 days during the growing season; reduce to every 2-3 weeks in winter dormancy | Toxic to pets |
| Daylily 'Chorus Line' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth and rebloom cycles; reduce to every 2-3 weeks in dormancy | Toxic to pets |
| Daylily 'Crimson Pirate' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 2-3 weeks in dormancy | Toxic to pets |
| Daylily 'Double River Wye' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 2-3 weeks during dormancy | Toxic to pets |
| Daylily 'Fragrant Returns' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; consistent moisture supports multiple rebloom cycles | Toxic to pets |
| Daylily 'Frans Hals' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Daylily 'Golden Zebra' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season; reduce to every 2-3 weeks as foliage dies back | Toxic to pets |
| Daylily 'Happy Returns' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during active growth | Toxic to pets |
| Daylily 'Hyperion' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 2-3 weeks in dormancy | Toxic to pets |
| Daylily 'Ice Carnival' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 2-3 weeks in dormancy | Toxic to pets |
| Daylily 'Joan Senior' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 1-2 weeks in winter (evergreen foliage requires some moisture year-round in mild climates) | Toxic to pets |
| Daylily 'Little Grapette' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; every 2-3 weeks in dormancy | Toxic to pets |
| Daylily 'Luxury Lace' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Mary Todd' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Midnight Magic' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Miss Amelia' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Mozhart' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Nile Crane' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Orange Velvet' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Pan for Gold' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Pardon Me' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Pearl Lewis' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Prairie Blue Eyes' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Primal Scream' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7 days in summer | Toxic to pets |
| Daylily 'Purple d'Oro' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Red Hot Returns' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Rosy Returns' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Ruby Spider' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7 days during summer | Toxic to pets |
| Daylily 'Sanctuary' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Daylily 'Siloam Double Classic' | Direct sun (at least 4-6 hours) | Roughly every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Siloam Virginia Henson' | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'So Lovely' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Stafford' | Direct sun (at least 4-6 hours) | Every 7-10 days, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Stella de Oro' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Daylily 'Stoke Poges' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Strawberry Candy' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Tiger Bloodlines' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Tuscawilla Snowfall' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'When I Dream' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Daylily 'Wind Frills' | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season, or when the top 5 cm of soil is dry | Toxic to pets |
| Debao Cycad | Bright indirect light (just back from a sunny window) | Every 7–14 days; reduce in winter | Toxic to pets |
| Debbie Graptoveria | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer | Pet-safe |
| Deceptive Mammillaria | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Deciduous Azalea 'Gibraltar' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply 1-2 times weekly through summer, more in heat | Toxic to pets |
| Degroot's Spire Arborvitae | Direct sun (at least 4-6 hours) | Two to three times weekly while young; weekly once established | Mildly toxic to pets |
| Delicate Air Plant | Bright indirect light (just back from a sunny window) | Soak for 20–30 minutes once a week | Pet-safe |
| Delphinium 'Black Knight' | Direct sun (at least 4-6 hours) | Every 3-5 days in growth; keep soil consistently moist, never dry | Toxic to pets |
| Delphinium 'Galahad' | Direct sun (at least 4-6 hours) | Every 3-5 days in growth; keep the soil consistently moist, never dry | Toxic to pets |
| Delphinium 'Magic Fountains' | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply 2-3 times weekly in growth | Toxic to pets |
| Delphinium 'Pacific Giant' | Direct sun (at least 4-6 hours) | Keep consistently moist; water deeply 2-3 times weekly in growth | Toxic to pets |
| Delphinium grandiflorum 'Blue Butterfly' | Direct sun (at least 4-6 hours) | Every 4-7 days; keep soil moist but well-drained, avoiding extremes | Toxic to pets |
| Delta Dracula | Medium indirect light (a couple of metres from a window) | Every 2-3 days, never allowing roots to dry out completely | Pet-safe |
| Delta Pure White pansy | Bright indirect light (just back from a sunny window) | Every 2–3 days in warm weather; weekly in cool, wet conditions | Pet-safe |
| Delta Vygie | Direct sun (at least 4-6 hours) | When the soil is fully dry, approximately every 10-14 days in the growing season; very sparingly once a month in winter | Pet-safe |
| Dendrobium loddigesii | Bright indirect light (just back from a sunny window) | Frequently in growth, roughly every 4-6 days; sparingly through the winter rest | Pet-safe |
| Denison's Vanda | Bright indirect light (just back from a sunny window) | Abundant watering in active growth (spring–summer); reduce to light morning fogging every few days in winter | Pet-safe |
| Dense Ginger Lily | Bright indirect light (just back from a sunny window) | Regularly through spring and summer; minimal in winter dormancy | Mildly toxic to pets |
| Dense Ginger Lily | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | Mildly toxic to pets |
| Densiformis Yew | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, roughly weekly while establishing | Toxic to pets |
| Deodar Cedar | Direct sun (at least 4-6 hours) | Weekly during first 2 years; drought-tolerant once established | Mildly toxic to pets |
| Deodar Cedar 'Karl Fuchs' | Direct sun (at least 4-6 hours) | Every 1-2 weeks while establishing, then sparingly | Mildly toxic to pets |
| Deparia acrostichoides | Low light (north window or shaded room) | Keep evenly moist; water when the top 2 cm starts to dry, roughly every 4-7 days in growth | Pet-safe |
| Desdemona Ligularia | Medium indirect light (a couple of metres from a window) | Constantly moist to wet; never let it dry out — water generously in dry spells, sometimes daily in heat | Mildly toxic to pets |
| Desert Bromeliad | Direct sun (at least 4-6 hours) | every 14–21 days in summer, rarely in winter | Pet-safe |
| Deshojo Japanese Maple | Bright indirect light (just back from a sunny window) | Keep consistently moist; frequently daily in summer | Mildly toxic to pets |
| Deutschland Astilbe | Bright indirect light (just back from a sunny window) | Keep soil consistently moist to wet; water when the top 2-3 cm dries, about every 3-5 days in summer | Mildly toxic to pets |
| Deutzia 'Elegantissima' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Pet-safe |
| Deutzia 'Magnifica' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Deutzia 'Mont Rose' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Deutzia 'Nikko' | Direct sun (at least 4-6 hours) | Weekly in the first season; during dry spells once established | Pet-safe |
| Deutzia 'Nikko' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during active growth | Mildly toxic to pets |
| Deutzia gracilis | Direct sun (at least 4-6 hours) | Weekly in the first year, then during dry spells | Pet-safe |
| Deutzia scabra 'Plena' | Direct sun (at least 4-6 hours) | Weekly while establishing, then in dry spells | Pet-safe |
| Deutzia x elegantissima 'Rosealind' | Direct sun (at least 4-6 hours) | Weekly while establishing, then during droughts | Pet-safe |
| Devil's-bit Scabious | Bright indirect light (just back from a sunny window) | Regular; keep soil consistently moist throughout spring and summer | Mildly toxic to pets |
| Diaguita Air Plant | Direct sun (at least 4-6 hours) | Mist or dunk thoroughly 2–3 times per week in summer; every 7–10 days in winter. | Pet-safe |
| Diana Clare Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry spells, more in pots | Mildly toxic to pets |
| Diana Rose of Sharon | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days in summer | Pet-safe |
| Diane's Gold Brunnera | Low light (north window or shaded room) | Keep soil evenly moist; water when the top 2-3 cm dries, roughly every 4-6 days in heat | Mildly toxic to pets |
| Dianthus 'Doris' | Direct sun (at least 4-6 hours) | Water when the top few cm of soil is dry; drought-tolerant once established | Toxic to pets |
| Dianthus 'Mrs Sinkins' | Direct sun (at least 4-6 hours) | Water when the top few cm of soil is dry; drought-tolerant once established | Toxic to pets |
| Dianthus deltoides | Direct sun (at least 4-6 hours) | Water when soil is dry; drought-tolerant once established | Toxic to pets |
| Dianthus gratianopolitanus 'Firewitch' | Direct sun (at least 4-6 hours) | Water when soil is dry; very drought-tolerant once established | Toxic to pets |
| Diascia 'Wink Coral Pink' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-3 days in warm weather | Pet-safe |
| Diascia barberae 'Piccadilly' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-3 days in warm weather | Pet-safe |
| Dicentra formosa 'Luxuriant' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil begins to dry, roughly every 5-7 days | Toxic to pets |
| Dickie's Bladder Fern | Low light (north window or shaded room) | 2-3 times per week in the growing season; reduce in winter dormancy | Pet-safe |
| Digitalis 'Camelot Cream' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly weekly in dry spells | Toxic to pets |
| Digyna Sweet Box | Low light (north window or shaded room) | Every 10-14 days during the first two growing seasons; established plants are drought-tolerant and need watering only in extended dry spells | Mildly toxic to pets |
| Dilys Cranesbill | Medium indirect light (a couple of metres from a window) | Water once a week during dry spells; largely self-sufficient once established in UK conditions | Pet-safe |
| Dimpled Trout Lily | Medium indirect light (a couple of metres from a window) | Consistently moist from emergence to dormancy (late winter to late spring) | Mildly toxic to pets |
| Dinter's Eye Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn through late winter; none in summer | Pet-safe |
| Dinter's Living Stone | Direct sun (at least 4-6 hours) | Every 2-4 weeks in summer growing season; none during autumn-winter leaf renewal | Pet-safe |
| Dinteranthus microspermus | Direct sun (at least 4-6 hours) | Sparingly in late-summer through autumn growth; near-dry the rest of the year | Pet-safe |
| Dinteranthus pole-evansii | Direct sun (at least 4-6 hours) | Minimal, only during late-summer to autumn growth; dry otherwise | Pet-safe |
| Dinteranthus puberulus | Direct sun (at least 4-6 hours) | Lightly in late-summer to autumn growth; near-dry the rest of the year | Pet-safe |
| Dinteranthus vanzylii | Direct sun (at least 4-6 hours) | Sparingly during late-summer to autumn growth; dry otherwise | Pet-safe |
| Dionaea muscipula 'Akai Ryu' | Direct sun (at least 4-6 hours) | Keep permanently wet; stand in 1-2 cm of pure water while growing | Pet-safe |
| Dionaea muscipula 'B52' | Direct sun (at least 4-6 hours) | Keep permanently wet; stand in 1-2 cm of pure water in the growing season | Pet-safe |
| Dioscorides' Arum | Bright indirect light (just back from a sunny window) | Moderate during active growth (autumn–spring); dry off completely in summer | Toxic to pets |
| Disa tripetaloides | Bright indirect light (just back from a sunny window) | Keep permanently moist; water daily or stand in a tray of pure water | Pet-safe |
| Disa uniflora | Bright indirect light (just back from a sunny window) | Keep continuously moist; water daily or stand in a shallow tray of pure water | Pet-safe |
| Disc Cactus | Direct sun (at least 4-6 hours) | When the mix has been completely dry for a few days, roughly every 14-21 days in summer; almost no water from October to March | Pet-safe |
| Distant-Flowered Dyckia | Direct sun (at least 4-6 hours) | Only when the potting mix is completely dry, roughly every 14-21 days in summer and every 30-45 days in winter | Mildly toxic to pets |
| Divergent Vanheerdea | Direct sun (at least 4-6 hours) | Every 14-21 days in the autumn-spring growing season when the leaves show slight wrinkling; completely dry in summer | Mildly toxic to pets |
| Divine Orange New Guinea Impatiens | Bright indirect light (just back from a sunny window) | Water when the top 2-3 cm of compost is dry, roughly every 2-3 days in warm weather; containers in full sun may need daily watering in peak summer | Mildly toxic to pets |
| Divisilobum Soft Shield Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days; reduce in winter | Pet-safe |
| Dodson's Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting or every 1-2 days; never allow to dry out | Pet-safe |
| Dog Rose | Direct sun (at least 4-6 hours) | Weekly during the first growing season; rarely once established | Pet-safe |
| Dogwood | Medium indirect light (a couple of metres from a window) | Low to moderate — water during establishment; drought-tolerant thereafter | Mildly toxic to pets |
| Dogwood 'Eddie's White Wonder' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply in dry spells | Mildly toxic to pets |
| Dolce Blackcurrant Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly | Pet-safe |
| Don Juan Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, more in heat | Pet-safe |
| Dorothy's Living Stone | Direct sun (at least 4-6 hours) | Every 2-3 weeks in summer (active growth); none from mid-autumn to late spring during rest | Pet-safe |
| Dorothy's Living Stones | Direct sun (at least 4-6 hours) | Seasonally — water only when the new leaf pair is actively growing (late summer to autumn); completely dry at all other times | Pet-safe |
| Double Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (keep soil consistently moist) | Toxic to pets |
| Double Bloodroot | Medium indirect light (a couple of metres from a window) | Every 5–7 days during spring growth; withhold or greatly reduce during summer dormancy | Toxic to pets |
| Double Click Snow Puff cosmos | Direct sun (at least 4-6 hours) | Weekly once established; more frequent in heat | Pet-safe |
| Double King Cup | Bright indirect light (just back from a sunny window) | Permanently moist to standing water 0–5 cm deep | Mildly toxic to pets |
| Double Knock Out Rose | Direct sun (at least 4-6 hours) | About 2.5 cm weekly, deep watering | Pet-safe |
| Double Marsh Marigold | Bright indirect light (just back from a sunny window) | Permanently moist to standing water 0–5 cm deep | Mildly toxic to pets |
| Double Pink Oleander | Direct sun (at least 4-6 hours) | Water weekly when establishing; drought-tolerant once established | Toxic to pets |
| Double-Flowered Bloodroot | Medium indirect light (a couple of metres from a window) | Moderate in spring; reduce as plant approaches dormancy in summer | Toxic to pets |
| Doublefile Viburnum 'Mariesii' | Direct sun (at least 4-6 hours) | Deep soak when the top 5 cm of soil dries, roughly weekly in the first two seasons | Pet-safe |
| Douglas Fir | Direct sun (at least 4-6 hours) | Regular during first 3 years; established trees tolerate moderate drought in cool climates | Mildly toxic to pets |
| Douglas Phlox | Direct sun (at least 4-6 hours) | Weekly when establishing; twice monthly once established | Mildly toxic to pets |
| Dove Masdevallia | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; the root zone must remain continuously moist | Pet-safe |
| Dove's-Foot Cranesbill | Direct sun (at least 4-6 hours) | Low; water only during extended drought | Pet-safe |
| Downy Oak | Direct sun (at least 4-6 hours) | Rarely once established; weekly in first 1–2 years | Mildly toxic to pets |
| Downy Painted Cup | Direct sun (at least 4-6 hours) | Infrequently, once established | Mildly toxic to pets |
| Downy Phlox | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2-3 weeks when established | Mildly toxic to pets |
| Downy Rock Jasmine | Direct sun (at least 4-6 hours) | Very sparingly; nearly dry between waterings | Mildly toxic to pets |
| Downy Sage | Direct sun (at least 4-6 hours) | Moderate; water when the top 5 cm of soil is dry | Mildly toxic to pets |
| Downy Yellow Violet | Medium indirect light (a couple of metres from a window) | Regular; keep evenly moist | Pet-safe |
| Dracula bella | Low light (north window or shaded room) | Keep continuously moist, watering every 2-3 days so the medium never dries fully | Mildly toxic to pets |
| Dracula simia | Low light (north window or shaded room) | Keep continuously moist, watering every 2-3 days so the medium never dries out | Mildly toxic to pets |
| Dracula sodiroi | Low light (north window or shaded room) | Keep evenly moist at all times, watering about every 2-4 days; the medium should never fully dry | Mildly toxic to pets |
| Dracula vampira | Low light (north window or shaded room) | Keep the medium evenly moist at all times; water roughly every 2-4 days, never allowing it to dry out | Mildly toxic to pets |
| Dracunculus canariensis | Direct sun (at least 4-6 hours) | Water in autumn-through-spring growth when the top few cm dry; keep dry during summer dormancy | Toxic to pets |
| Dragon's Blood Stonecrop | Direct sun (at least 4-6 hours) | When soil is dry, about every 10-14 days in summer; minimal in winter | Pet-safe |
| Drakensberg Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; minimal in winter | Toxic to pets |
| Dreaming Air Plant | Medium indirect light (a couple of metres from a window) | Mist 2–3 times per week; soak weekly | Pet-safe |
| Drooping Spleenwort | Medium indirect light (a couple of metres from a window) | Every 5–10 days; allow surface to approach dryness between waterings | Pet-safe |
| Drooping Star of Bethlehem | Bright indirect light (just back from a sunny window) | Low; rainfall usually sufficient in temperate gardens | Toxic to pets |
| Drooping Star of Bethlehem | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry during active growth, roughly every 7-10 days | Toxic to pets |
| Drooping Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist throughout spring; can tolerate slightly drier conditions in summer dormancy. | Mildly toxic to pets |
| Druce's Cranesbill | Bright indirect light (just back from a sunny window) | Water during establishment; once established largely drought-tolerant | Pet-safe |
| Drummond's Aster | Medium indirect light (a couple of metres from a window) | Low to moderate | Pet-safe |
| Drummond's Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method year-round (reduced in dormancy) | Pet-safe |
| dryas primulina | Medium indirect light (a couple of metres from a window) | Every 7–10 days in spring–summer; every 14–21 days in winter | Pet-safe |
| Dryopteris affinis 'Cristata' | Low light (north window or shaded room) | Keep soil consistently moist; water deeply during dry spells, roughly weekly in summer | Pet-safe |
| Dryopteris carthusiana | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist, watering when the top 1-2 cm dries, roughly every 4-6 days | Mildly toxic to pets |
| Dryopteris championii | Low light (north window or shaded room) | Keep evenly moist; water deeply in dry spells, roughly weekly in summer heat | Pet-safe |
| Dryopteris dilatata | Medium indirect light (a couple of metres from a window) | Keep soil moist, watering when the top 2-3 cm dries, roughly every 5-7 days; established plants tolerate short dry spells | Mildly toxic to pets |
| Dryopteris dilatata 'Crispa Whiteside' | Medium indirect light (a couple of metres from a window) | Keep soil moist, watering when the top 2-3 cm dries, roughly every 5-7 days; established clumps tolerate brief dryness | Mildly toxic to pets |
| Dryopteris filix-mas 'Linearis Polydactyla' | Low light (north window or shaded room) | Keep soil consistently moist; water during dry spells so it never dries out | Mildly toxic to pets |
| Dryopteris goldiana | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Dryopteris intermedia | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist, watering when the top 2-3 cm dries, roughly every 5-7 days; established plants take brief dry spells | Mildly toxic to pets |
| Dryopteris tokyoensis | Low light (north window or shaded room) | Keep constantly moist to wet; never allow to dry out, watering as often as needed in summer | Pet-safe |
| Dryopteris uniformis | Low light (north window or shaded room) | Keep evenly moist; water deeply during dry spells, roughly weekly in summer | Pet-safe |
| Duclouxs Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growth; sparingly in winter | Pet-safe |
| Durat's Air Plant | Bright indirect light (just back from a sunny window) | Mist thoroughly 2–3 times per week; a 20-minute soak once a week is sufficient in summer. Reduce to every 10–14 days in winter. | Pet-safe |
| Dusky Coral Pea | Direct sun (at least 4-6 hours) | Low once established; moderate during establishment | Mildly toxic to pets |
| Dutch Iris | Direct sun (at least 4-6 hours) | Moderate during growth; dry in summer dormancy | Toxic to pets |
| Dutchman's pipe | Bright indirect light (just back from a sunny window) | Every 5–7 days during the growing season; less in cool dormancy. | Toxic to pets |
| Dwarf Alberta Spruce | Direct sun (at least 4-6 hours) | Every 5-7 days when establishing; deep soak when the top few cm of soil dry out | Pet-safe |
| Dwarf Antimima | Bright indirect light (just back from a sunny window) | Sparingly in summer; moderately in autumn–spring | Pet-safe |
| Dwarf Astilbe 'Pumila' | Bright indirect light (just back from a sunny window) | Keep soil moist; water every 3-5 days in summer, more in heat | Mildly toxic to pets |
| Dwarf Bamboo | Bright indirect light (just back from a sunny window) | 2–3 times per week in summer, reduce in winter | Pet-safe |
| Dwarf Bearded Iris | Direct sun (at least 4-6 hours) | Weekly during active growth; minimal in summer dormancy | Mildly toxic to pets |
| Dwarf Birch | Direct sun (at least 4-6 hours) | Regular moisture; do not allow to dry out, especially in summer | Pet-safe |
| Dwarf blue rhododendron | Bright indirect light (just back from a sunny window) | Every 7–14 days in the growing season; sparingly in winter | Toxic to pets |
| Dwarf Blue Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days when young; deep, infrequent watering once established | Pet-safe |
| Dwarf Cedar of Lebanon | Direct sun (at least 4-6 hours) | Weekly when young; bi-weekly once established | Pet-safe |
| Dwarf Chin Cactus | Bright indirect light (just back from a sunny window) | When soil is completely dry, roughly every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Dwarf Coast Redwood | Direct sun (at least 4-6 hours) | Every 1–2 weeks; more in summer heat | Pet-safe |
| Dwarf Crocus | Direct sun (at least 4-6 hours) | Very low — dry Mediterranean dormancy essential; water only at planting and rely on winter rainfall | Mildly toxic to pets |
| Dwarf Cycad | Bright indirect light (just back from a sunny window) | Every 2–4 weeks | Toxic to pets |
| Dwarf Fan Palm | Bright indirect light (just back from a sunny window) | Every 7–10 days during growing season; reduce to fortnightly in cooler months | Pet-safe |
| Dwarf Fernleaf Bamboo | Medium indirect light (a couple of metres from a window) | Once or twice per week during the growing season; reduce significantly in winter | Pet-safe |
| Dwarf Frailea | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 12-16 days in summer | Pet-safe |
| Dwarf Golden Oriental Arborvitae | Direct sun (at least 4-6 hours) | Once per week when the top 2-3 cm of soil is dry; more frequently in hot, dry summers | Toxic to pets |
| Dwarf Greenstripe Bamboo | Bright indirect light (just back from a sunny window) | 2–3 times per week in summer, once per week in winter | Pet-safe |
| Dwarf Hinoki Cypress | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days depending on season | Mildly toxic to pets |
| Dwarf Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil feels dry, roughly every 5-7 days in summer | Pet-safe |
| Dwarf Horsetail | Medium indirect light (a couple of metres from a window) | Consistently wet; stand pot in water tray | Mildly toxic to pets |
| Dwarf Korean Lilac | Direct sun (at least 4-6 hours) | Weekly while establishing, then every 1-2 weeks in dry spells | Pet-safe |
| Dwarf Lady's Mantle | Bright indirect light (just back from a sunny window) | Weekly during the growing season; established plants tolerate some drought | Pet-safe |
| Dwarf Lewisia | Direct sun (at least 4-6 hours) | Moderate during spring growth; completely dry in summer | Pet-safe |
| Dwarf Mountain Laurel Elf | Bright indirect light (just back from a sunny window) | Regular; maintain even moisture | Toxic to pets |
| Dwarf Palmetto | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 5-7 days in growth | Mildly toxic to pets |
| Dwarf Pampas Grass | Direct sun (at least 4-6 hours) | Moderate; drought-tolerant once established | Mildly toxic to pets |
| Dwarf Pieris | Bright indirect light (just back from a sunny window) | Regular; keep evenly moist | Toxic to pets |
| Dwarf Snowberry | Bright indirect light (just back from a sunny window) | Regularly, keeping soil consistently moist | Toxic to pets |
| Dwarf Solomon's Seal | Medium indirect light (a couple of metres from a window) | Every 5–7 days during active growth; less when dormant | Mildly toxic to pets |
| Dwarf Sugar Palm | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Dwarf Sugar Palm | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer; every 14 days in winter | Pet-safe |
| Dwarf Sweet Flag | Medium indirect light (a couple of metres from a window) | Permanently moist to wet; tolerate shallow submersion | Pet-safe |
| Dwarf Sweet Flag | Bright indirect light (just back from a sunny window) | Keep soil permanently moist; water as soon as the surface feels barely dry | Mildly toxic to pets |
| Dwarf Trillium | Low light (north window or shaded room) | Keep soil consistently moist from spring emergence until dormancy; minimal watering once dormant | Mildly toxic to pets |
| Dwarf Tulip | Direct sun (at least 4-6 hours) | Sparingly; water at planting then only if soil dries out completely; cease watering after foliage dies back | Toxic to pets |
| Dwarf Windmill Palm | Direct sun (at least 4-6 hours) | Weekly while establishing; little supplemental water once mature | Pet-safe |
| Dyckia 'Cherry Cola' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth, sparingly in winter | Pet-safe |
| Dyckia brevifolia | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth, far less in winter | Pet-safe |
| Dyckia fosteriana | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in growth, rarely in winter | Pet-safe |
| Dyckia leptostachya | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Mildly toxic to pets |
| Dyckia velascana | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in growth, minimal in winter | Pet-safe |
| Dyer's Cycad | Direct sun (at least 4-6 hours) | Every 3–6 weeks | Toxic to pets |
| Dyer's Ice Plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in growing season; reduce to monthly or less in winter | Pet-safe |
| Dyer's Macrozamia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in growing season; once a month or less in summer drought/winter | Toxic to pets |
| Dynastes Masdevallia | Medium indirect light (a couple of metres from a window) | Water when medium approaches dryness, roughly every 1-2 days in warm months | Pet-safe |
| Eared Sage | Bright indirect light (just back from a sunny window) | Weekly in summer, less in winter | Pet-safe |
| Early Purple Orchid | Medium indirect light (a couple of metres from a window) | Moist in spring; reduce significantly once summer dormancy begins | Mildly toxic to pets |
| Early Squill | Direct sun (at least 4-6 hours) | Water during active growth; keep drier in summer | Toxic to pets |
| Earth-colored Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during the active autumn-to-spring period; none in summer | Pet-safe |
| East Himalayan Fir | Direct sun (at least 4-6 hours) | Regularly during establishment; drought-tolerant once mature | Pet-safe |
| Easter Lily | Bright indirect light (just back from a sunny window) | When top 2–3 cm of soil is dry | Toxic to pets |
| Easter Lily Cactus Clump | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Eastern Bee Balm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Pet-safe |
| Eastern Cape Blue Cycad | Direct sun (at least 4-6 hours) | Every 3–6 weeks in summer; once a month or less in winter | Toxic to pets |
| Eastern Cape Cycad | Direct sun (at least 4-6 hours) | Every 21–30 days; extremely drought-tolerant | Toxic to pets |
| Eastern Cape Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks; less in winter | Toxic to pets |
| Eastern Cyclamen | Medium indirect light (a couple of metres from a window) | Minimal in summer dormancy; rely on rainfall during autumn–spring growth | Toxic to pets |
| Eastern Everlasting | Direct sun (at least 4-6 hours) | Low — water only when the top 2 cm of soil is dry; drought-tolerant once established | Mildly toxic to pets |
| Eastern Hemlock | Medium indirect light (a couple of metres from a window) | Weekly during establishment; regular moisture required long-term | Pet-safe |
| Eastern Skunk Cabbage | Low light (north window or shaded room) | Continuously waterlogged; tolerates standing water | Toxic to pets |
| Ebracteola montis-moltkei | Direct sun (at least 4-6 hours) | Only when soil is fully dry, roughly every 10-14 days in growth; keep nearly dry when dormant | Mildly toxic to pets |
| Eccremocarpus scaber | Direct sun (at least 4-6 hours) | Keep evenly moist through the growing season; water container plants regularly | Mildly toxic to pets |
| Echeveria 'Minima' | Direct sun (at least 4-6 hours) | When the soil is completely dry, about every 1-2 weeks in summer | Pet-safe |
| Echeveria 'Tsunami' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-2 weeks in summer | Pet-safe |
| Echeveria subsessilis 'Morning Beauty' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-2 weeks in summer | Pet-safe |
| Echidna Barrel Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, approximately every 14-21 days in the growing season | Pet-safe |
| Echidna Orchid | Medium indirect light (a couple of metres from a window) | Daily misting if mounted; every 1–2 days if potted | Pet-safe |
| Echinacea 'After Midnight' | Direct sun (at least 4-6 hours) | Once or twice weekly during establishment; once every 10–14 days when fully established | Pet-safe |
| Echinacea 'Baby White Swan' | Direct sun (at least 4-6 hours) | Once or twice a week in year one; once every 10–14 days when established | Pet-safe |
| Echinacea 'Cheyenne Spirit' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; weekly while establishing, then mainly in drought | Pet-safe |
| Echinacea 'Cheyenne Spirit' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days | Mildly toxic to pets |
| Echinacea 'Coconut Lime' | Direct sun (at least 4-6 hours) | Once or twice a week in the first year; once a week or less when fully established | Pet-safe |
| Echinacea 'Green Envy' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days once established | Mildly toxic to pets |
| Echinacea 'Harvest Moon' | Direct sun (at least 4-6 hours) | Every 7-10 days once established; weekly during the first season | Pet-safe |
| Echinacea 'Hot Papaya' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Echinacea 'Hula Dancer' | Direct sun (at least 4-6 hours) | When the top 5-6 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Echinacea 'Magnus' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly until established | Pet-safe |
| Echinacea 'Pink Double Delight' | Direct sun (at least 4-6 hours) | Every 7-10 days once established; more frequently during the first growing season | Pet-safe |
| Echinacea 'Pixie Meadowbrite' | Direct sun (at least 4-6 hours) | Once or twice a week during establishment; every 10–14 days when established | Pet-safe |
| Echinacea 'PowWow Wild Berry' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Echinacea 'Ruby Star' | Direct sun (at least 4-6 hours) | Once or twice a week during the first growing season; deeply once a week or less when established | Pet-safe |
| Echinacea 'Sunset' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days once established | Mildly toxic to pets |
| Echinacea 'Tomato Soup' | Direct sun (at least 4-6 hours) | Once or twice a week during the first growing season; every 10–14 days once established | Pet-safe |
| Echinacea 'Virgin' | Direct sun (at least 4-6 hours) | Once or twice a week for the first growing season; once weekly to once every two weeks when established | Pet-safe |
| Echinacea 'White Swan' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly until established | Pet-safe |
| Echinocereus coccineus | Direct sun (at least 4-6 hours) | When soil is bone-dry in growth, roughly every 10-14 days; none over winter | Pet-safe |
| Echinocereus engelmannii | Direct sun (at least 4-6 hours) | When soil is fully dry in growing season, about every 10-14 days; keep dry in winter | Pet-safe |
| Echinocereus pectinatus | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in active growth; none in winter | Pet-safe |
| Echinops bannaticus 'Taplow Blue' | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water new plants until settled | Pet-safe |
| Echinops ritro | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water new plants until rooted | Pet-safe |
| Echinops ritro 'Veitch's Blue' | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water young plants until rooted | Pet-safe |
| Echinopsis | Direct sun (at least 4-6 hours) | When the top few cm are dry, about every 1-2 weeks in summer; sparingly in winter | Toxic to pets |
| Ecuador Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (consistent moisture essential) | Toxic to pets |
| Edging lobelia | Bright indirect light (just back from a sunny window) | Every 2–3 days in warm weather; every 5–7 days in cool conditions | Toxic to pets |
| Edible Fockea | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season (spring–autumn); once a month or less in winter | Mildly toxic to pets |
| Edith's Air Plant | Direct sun (at least 4-6 hours) | Every 2–3 days by misting | Pet-safe |
| Ehlers' Butterwort | Bright indirect light (just back from a sunny window) | Careful watering from below; drier in winter | Pet-safe |
| Elegant Ball Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer; every 3-4 weeks in winter | Pet-safe |
| Elegant clarkia | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant once established | Pet-safe |
| Elephant Ears 'Bressingham White' | Medium indirect light (a couple of metres from a window) | Every 7-14 days; established plants are relatively drought-tolerant but perform best with consistent moisture | Mildly toxic to pets |
| Elephant Tree | Direct sun (at least 4-6 hours) | Once a month supplemental irrigation in summer outdoors; every 2–3 weeks for container plants in active growth; minimal in winter | Mildly toxic to pets |
| Elise's Cotyledon | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season, every 3–5 weeks in winter | Toxic to pets |
| Elizabeth Magnolia | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2 weeks in dry periods once mature | Mildly toxic to pets |
| Elk Blue Rush | Bright indirect light (just back from a sunny window) | Frequent to constant — keep soil consistently moist or wet | Pet-safe |
| Elk Horns Pig's Ear | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring/summer; monthly or less in autumn/winter | Toxic to pets |
| Elkhorn Plant | Bright indirect light (just back from a sunny window) | Every 2–4 weeks in growing season; monthly or less in summer dormancy | Mildly toxic to pets |
| Elliptic Ginger Lily | Bright indirect light (just back from a sunny window) | Moderate — water regularly but allow soil to partially dry between waterings | Mildly toxic to pets |
| Ellwoodii False Cypress | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply weekly while establishing, then during dry spells | Toxic to pets |
| Elongated Sun Pitcher | Bright indirect light (just back from a sunny window) | Soil kept consistently moist to wet year-round; shallow tray method acceptable | Mildly toxic to pets |
| Elymaitic Rosularia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring/summer; monthly or less in autumn/winter | Mildly toxic to pets |
| Embothrium coccineum | Direct sun (at least 4-6 hours) | Keep the root zone evenly moist; water every 5-10 days in dry or hot spells, particularly while establishing | Mildly toxic to pets |
| Emei Mountain Begonia | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growth; reduce significantly in winter dormancy | Toxic to pets |
| Emerald Blue Creeping Phlox | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; drought-tolerant once established (second year onward) | Pet-safe |
| Emerald Gaiety Euonymus | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Emerald Green Arborvitae | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week when establishing; weekly once rooted in | Mildly toxic to pets |
| Emerald Green Arborvitae | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days for young plants | Mildly toxic to pets |
| Emerald n Gold Euonymus | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Emory's Barrel Cactus | Direct sun (at least 4-6 hours) | Every 3-4 weeks in spring/summer; once a month or less in autumn; withheld almost entirely in winter | Mildly toxic to pets |
| Emperor Tulip | Direct sun (at least 4-6 hours) | Rainfall-dependent during growth; summer dry period essential | Toxic to pets |
| Empress of India Nasturtium | Direct sun (at least 4-6 hours) | When the top 3–5 cm of soil is dry, roughly every 7–10 days | Mildly toxic to pets |
| Empress Wu Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 4-6 days in growth | Toxic to pets |
| Encore Azalea 'Autumn Twist' | Bright indirect light (just back from a sunny window) | About 2-3 times per week while establishing, then weekly; water when the top 2-3 cm of soil is dry | Toxic to pets |
| Encrusted Saxifrage | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; rarely in winter | Pet-safe |
| Endres's Bladderwort | Bright indirect light (just back from a sunny window) | Keep substrate continuously moist; water every 1–3 days or as sphagnum surface begins to dry slightly | Mildly toxic to pets |
| English Bluebell | Medium indirect light (a couple of metres from a window) | Moderate; naturally moist in spring, drier in summer | Toxic to pets |
| English ivy | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil is dry, every 7-10 days | Toxic to pets |
| English Yew Bonsai | Bright indirect light (just back from a sunny window) | When the top 2-3 cm is dry, around every 2-4 days in summer and less in winter | Toxic to pets |
| Engraved Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks from late summer through autumn (active growth); withheld or near-zero from May through August | Pet-safe |
| Entire-leaved Primrose | Direct sun (at least 4-6 hours) | Every 7–10 days in spring; minimal in summer and winter | Mildly toxic to pets |
| Equisetum hyemale | Direct sun (at least 4-6 hours) | Keep constantly wet; never let the rootzone dry out | Mildly toxic to pets |
| Equisetum japonicum | Direct sun (at least 4-6 hours) | Keep permanently wet or in shallow standing water | Mildly toxic to pets |
| Erman's Birch | Direct sun (at least 4-6 hours) | Regular watering for first 2–3 years; occasional once established | Pet-safe |
| Ermine Stomatium | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days during the growing season; once every 4-6 weeks or less in winter | Mildly toxic to pets |
| Ernst's Spurflower | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in summer; monthly or less in winter | Mildly toxic to pets |
| Eryngium 'Jade Frost' | Direct sun (at least 4-6 hours) | Water while establishing, then only during prolonged drought | Mildly toxic to pets |
| Eryngium × zabelii 'Big Blue' | Direct sun (at least 4-6 hours) | Sparingly once established; water only in prolonged drought, roughly every 2-3 weeks | Mildly toxic to pets |
| Eryngium bourgatii 'Picos Blue' | Direct sun (at least 4-6 hours) | Minimal once established; only during extended dry spells, roughly every 2-3 weeks | Mildly toxic to pets |
| Eryngium giganteum 'Silver Ghost' | Direct sun (at least 4-6 hours) | Rarely once established; only in prolonged drought, roughly every 2-3 weeks | Mildly toxic to pets |
| Eryngium planum 'Blue Hobbit' | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water new plants until rooted | Mildly toxic to pets |
| Erythronium 'Pagoda' | Bright indirect light (just back from a sunny window) | Keep soil cool and evenly moist in spring; never let bulbs dry out completely | Mildly toxic to pets |
| Eschscholzia californica 'Thai Silk Rose Chiffon' | Direct sun (at least 4-6 hours) | When the soil is dry several centimetres down, roughly every 7-14 days | Mildly toxic to pets |
| Escobar's Lepanthes | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; keep medium consistently moist | Pet-safe |
| Escobar's Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting or near-daily watering; substrate should never fully dry out | Pet-safe |
| Espostoa lanata | Direct sun (at least 4-6 hours) | When the top few centimetres are dry, about every 2 weeks in summer; sparingly in winter | Pet-safe |
| Espostoa melanostele | Direct sun (at least 4-6 hours) | When the upper soil is dry, about every 2 weeks in summer; sparingly in winter | Pet-safe |
| Etched Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the autumn–spring growing period; completely dry through June–August | Pet-safe |
| Ethiopian Banana | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 4-6 days during warm months | Pet-safe |
| Etruscan honeysuckle | Direct sun (at least 4-6 hours) | Weekly during dry spells; established plants are drought-tolerant | Mildly toxic to pets |
| Eucryphia × nymansensis 'Nymansay' | Direct sun (at least 4-6 hours) | Keep the root zone consistently moist; water every 5-10 days in dry or hot weather, especially while establishing | Mildly toxic to pets |
| Euphorbia clavarioides | Direct sun (at least 4-6 hours) | When fully dry, about every 2-3 weeks in summer; keep bone-dry in winter | Toxic to pets |
| Euphorbia horrida | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Toxic to pets |
| Euphorbia meloformis | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in summer | Toxic to pets |
| Euphorbia polygona | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Toxic to pets |
| European Ash | Direct sun (at least 4-6 hours) | Moderate; deep watering during drought in first 3 years | Pet-safe |
| European Beech | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil starts to dry, frequently daily in summer | Mildly toxic to pets |
| European Chain Fern | Medium indirect light (a couple of metres from a window) | 3-4 times per week in growing season; reduce slightly in winter | Mildly toxic to pets |
| European feather grass | Direct sun (at least 4-6 hours) | Weekly in the first growing season; only during extreme drought thereafter | Pet-safe |
| European Hornbeam | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil begins to dry, often daily in summer | Mildly toxic to pets |
| European Larch | Direct sun (at least 4-6 hours) | When the surface just starts to dry, frequently twice daily in summer heat | Mildly toxic to pets |
| European Wild Ginger | Low light (north window or shaded room) | Moderate; water when the top 3–4 cm of soil dries out | Toxic to pets |
| Everflame Hook Sedge | Direct sun (at least 4-6 hours) | Keep evenly moist; water weekly in dry weather and keep containers from drying out | Mildly toxic to pets |
| Evergold Sedge | Bright indirect light (just back from a sunny window) | Keep evenly moist; water when the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Evergreen Candytuft | Direct sun (at least 4-6 hours) | Every 1–2 weeks when establishing; drought-tolerant once established | Mildly toxic to pets |
| Everlasting Sweet Pea | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant once mature | Pet-safe |
| Excellent Pitcher Plant | Direct sun (at least 4-6 hours) | Keep in a standing tray of 2–5 cm (1–2 in) of pure water at all times during the growing season; reduce in winter dormancy | Pet-safe |
| Exquisite Masdevallia | Medium indirect light (a couple of metres from a window) | Every 1–3 days depending on season and medium; do not allow to dry | Pet-safe |
| Eyelash Sage | Bright indirect light (just back from a sunny window) | Every 7-10 days once established | Pet-safe |
| Ezo Spruce | Direct sun (at least 4-6 hours) | When the top centimetre of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Fagus sylvatica 'Dawyck' | Direct sun (at least 4-6 hours) | Weekly while establishing; water in dry spells | Toxic to pets |
| Fagus sylvatica 'Pendula' | Direct sun (at least 4-6 hours) | Weekly deep watering for the first 2-3 years, then rainfall-reliant | Mildly toxic to pets |
| Fagus sylvatica 'Purpurea' | Direct sun (at least 4-6 hours) | Weekly deep soak in the first 2-3 years, then rainfall-reliant | Mildly toxic to pets |
| Fairies' Thimbles | Bright indirect light (just back from a sunny window) | Weekly during active growth; less in winter | Pet-safe |
| fairy aprons | Bright indirect light (just back from a sunny window) | Keep media constantly wet; use the tray method year-round | Pet-safe |
| Fairy Bells | Bright indirect light (just back from a sunny window) | Regular watering autumn to spring; completely dry in summer | Mildly toxic to pets |
| Fairy fan-flower | Direct sun (at least 4-6 hours) | Every 3–5 days in containers; every 7–10 days in-ground once established | Pet-safe |
| Fairy Thimbles | Bright indirect light (just back from a sunny window) | Moderate — water regularly during the growing season | Mildly toxic to pets |
| Fallopia baldschuanica | Direct sun (at least 4-6 hours) | Water deeply during the first two growing seasons; established plants rarely need irrigation | Mildly toxic to pets |
| False Comb Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer and essentially none in winter | Pet-safe |
| False Peyote | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 14-21 days in summer; minimal or none in winter | Pet-safe |
| False Solomon's Seal | Medium indirect light (a couple of metres from a window) | 2–3 times per week in the growing season; reduce in dormancy | Mildly toxic to pets |
| Falstaff Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat or sandy soil | Pet-safe |
| Fama White scabiosa | Direct sun (at least 4-6 hours) | Every 7–10 days; less in winter | Pet-safe |
| Fan Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week, or a 15–20 minute soak once a week | Pet-safe |
| Farewell-to-spring | Direct sun (at least 4-6 hours) | Every 7–10 days; reduce once established | Pet-safe |
| Farrer's Gentian | Bright indirect light (just back from a sunny window) | Keep consistently moist throughout the growing season | Mildly toxic to pets |
| Fastigiata Yew | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Fat Albert Blue Spruce | Direct sun (at least 4-6 hours) | Water deeply weekly for the first two to three years, then during prolonged dry spells | Mildly toxic to pets |
| Faucaria Bosscheana | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in growth and far less in winter | Mildly toxic to pets |
| Faucaria lupina | Direct sun (at least 4-6 hours) | When soil is fully dry, mainly in spring and autumn growth; reduce in summer and winter | Mildly toxic to pets |
| feather grass | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; minimal in winter | Pet-safe |
| Featherleaf Rodgersia 'Superba' | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 2-3 times per week in dry spells, more in summer heat | Mildly toxic to pets |
| feathertop grass | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2 weeks once established | Pet-safe |
| Feathery Air Plant | Bright indirect light (just back from a sunny window) | Mist lightly every 2–3 days in warm conditions; reduce to every 4–5 days in cooler weather. | Pet-safe |
| Feelin' Blue Deodar Cedar | Direct sun (at least 4-6 hours) | Weekly when young; monthly once established | Pet-safe |
| Felicia Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during the growing season, more often in hot weather | Pet-safe |
| Fennel-Leaved Sea Lavender | Direct sun (at least 4-6 hours) | Low to moderate — water to establish, then sparingly | Pet-safe |
| Fern-leaf Yarrow 'Gold Plate' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days; very infrequent once established | Toxic to pets |
| Ferner Osten Maiden Grass | Direct sun (at least 4-6 hours) | Weekly during the first season; established clumps tolerate drought and need water only in extended dry spells | Mildly toxic to pets |
| Fetcani Pass Twinspur | Bright indirect light (just back from a sunny window) | Water when top 2–3 cm of soil dries out | Mildly toxic to pets |
| Few-flowered Abutilon | Bright indirect light (just back from a sunny window) | Every 7–10 days in active growth; fortnightly in cooler months | Pet-safe |
| Few-flowered Lysionotus | Medium indirect light (a couple of metres from a window) | Once or twice a week in the growing season; once a week or less in winter | Pet-safe |
| Few-fruited Tongue Plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; once monthly or less in winter | Mildly toxic to pets |
| Few-Ribbed Matucana | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, every 7-14 days in summer | Pet-safe |
| Few-Toothed Tiger Jaws | Direct sun (at least 4-6 hours) | Every 2–4 weeks during active growth (late summer–autumn); sparingly in winter and spring | Pet-safe |
| Fida's Weingartia | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in spring and summer; suspend almost entirely from mid-autumn through winter. | Pet-safe |
| Fiddle-leaf Pelargonium | Direct sun (at least 4-6 hours) | Water every 10-14 days in the growing season; reduce to monthly or less in winter | Toxic to pets |
| Fiebrig's Crown Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days in spring and summer; every 4-6 weeks in autumn; minimal to none in winter | Pet-safe |
| Field Bindweed | Direct sun (at least 4-6 hours) | Low — extremely drought-tolerant once established | Toxic to pets |
| Field Elm Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil starts to dry, often daily in warm weather | Mildly toxic to pets |
| Field Gladiolus | Direct sun (at least 4-6 hours) | Moderate during late winter to late spring growing season; dry summer dormancy required | Toxic to pets |
| Field marigold | Direct sun (at least 4-6 hours) | Weekly during dry spells; self-sufficient once established | Pet-safe |
| Field poppy | Direct sun (at least 4-6 hours) | Once established, every 10–14 days; keep seedbed moist until germination | Mildly toxic to pets |
| Field Sage | Direct sun (at least 4-6 hours) | Every 10-14 days once established; minimal in winter | Pet-safe |
| Field Scabious | Direct sun (at least 4-6 hours) | Water during establishment and dry spells, then occasionally | Mildly toxic to pets |
| Fiery Masdevallia | Bright indirect light (just back from a sunny window) | Daily in warm weather; every 3–5 days in cool/winter months | Pet-safe |
| Fiesta Double Pink Impatiens | Medium indirect light (a couple of metres from a window) | Keep compost evenly moist at all times; water every 1-2 days in warm weather as double-flowered types are slightly more moisture-demanding than singles | Mildly toxic to pets |
| Filicoides Hinoki Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days when young, then when the top few cm of soil dry | Mildly toxic to pets |
| Filifera Aurea Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days while establishing, then when the top few cm of soil dry | Mildly toxic to pets |
| Fine-lined Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days in autumn to early spring only; completely withheld in summer and mid-winter | Pet-safe |
| Finger Mesemb | Direct sun (at least 4-6 hours) | Every 14-21 days in autumn through spring when the substrate is fully dry; essentially none during summer dormancy | Mildly toxic to pets |
| Finger Poppy Mallow | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; highly drought-tolerant | Mildly toxic to pets |
| Fingered Sedge | Low light (north window or shaded room) | Moderate; keep moist but not waterlogged | Pet-safe |
| Fingertips | Bright indirect light (just back from a sunny window) | Every 2–3 weeks autumn through spring; minimal to none in summer | Pet-safe |
| Fire Alarm Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about weekly | Pet-safe |
| Fire and Ice Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Fire Barrel Cactus | Direct sun (at least 4-6 hours) | Every 3-4 weeks in the growing season (spring–summer); once every 6-8 weeks in autumn; almost none in winter | Mildly toxic to pets |
| Firebush | Direct sun (at least 4-6 hours) | Weekly until established; every 10–14 days once mature | Mildly toxic to pets |
| Firecracker Plant | Direct sun (at least 4-6 hours) | Every 5–7 days during growth; every 10–14 days once established | Mildly toxic to pets |
| Firethorn Bonsai | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil begins to dry, often daily in summer heat | Mildly toxic to pets |
| Fishhook Barrel | Direct sun (at least 4-6 hours) | When fully dry, about every 10-14 days in summer; keep dry in winter | Pet-safe |
| Fishhook Barrel Cactus | Direct sun (at least 4-6 hours) | When the soil is bone dry, every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Fishtail Holly Fern | Low light (north window or shaded room) | Every 7–10 days; less in winter | Pet-safe |
| Fitzgerald's Sarcochilus | Bright indirect light (just back from a sunny window) | Every 3-5 days during the growing season; every 7-10 days in cooler months | Pet-safe |
| Five-leaf akebia | Medium indirect light (a couple of metres from a window) | Once a week when establishing; drought-tolerant once mature | Mildly toxic to pets |
| Flag Pansy Orchid | Bright indirect light (just back from a sunny window) | When the medium is nearly dry, roughly every 5-7 days in summer | Pet-safe |
| Flame nasturtium | Bright indirect light (just back from a sunny window) | Water regularly to maintain consistent moisture, especially in spring and summer | Pet-safe |
| Flame vine | Direct sun (at least 4-6 hours) | Every 7–10 days during establishment; once every 2–3 weeks once established. | Mildly toxic to pets |
| Flamingo pieris | Bright indirect light (just back from a sunny window) | Weekly during dry weather | Toxic to pets |
| Flanagan's Sage | Direct sun (at least 4-6 hours) | Every 10-14 days during the growing season; rarely in winter | Pet-safe |
| Flat-Leaved Crassula | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, approximately every 10-14 days in summer | Toxic to pets |
| Flat-Leaved Dyckia | Direct sun (at least 4-6 hours) | When the compost is completely dry, roughly every 14-21 days in summer | Pet-safe |
| Fleshy Orbea | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 10-14 days in summer and monthly or less in winter | Mildly toxic to pets |
| Flexuose Nerine | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days during active growth | Toxic to pets |
| Floating Bur-reed | Direct sun (at least 4-6 hours) | Fully aquatic; floating or lightly rooted in 10–80 cm of water | Pet-safe |
| Florida Arrowroot | Bright indirect light (just back from a sunny window) | Every 14–21 days; much less in winter | Toxic to pets |
| Florida Silver Palm | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Florida Torreya | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, roughly every 10-14 days | Toxic to pets |
| Florist's Cyclamen | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil feels dry, roughly every 5-7 days | Toxic to pets |
| Flower Carpet Rose | Direct sun (at least 4-6 hours) | Deeply once a week in the growing season; more in containers or heat | Pet-safe |
| Flowering Cherry 'Kanzan' | Direct sun (at least 4-6 hours) | Water young trees weekly in dry spells; mature trees rarely need watering | Toxic to pets |
| Flowering currant | Bright indirect light (just back from a sunny window) | Weekly when establishing; drought-tolerant once mature | Mildly toxic to pets |
| Flowering Dogwood | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply weekly in dry spells | Mildly toxic to pets |
| Flowering Dogwood 'Cherokee Chief' | Bright indirect light (just back from a sunny window) | Weekly deep watering, more in drought | Pet-safe |
| Flowering Quince 'Crimson and Gold' | Direct sun (at least 4-6 hours) | Water while establishing; drought-tolerant once settled | Mildly toxic to pets |
| Flowering Quince 'Texas Scarlet' | Direct sun (at least 4-6 hours) | Weekly in the first year; rarely needed once established | Mildly toxic to pets |
| Fly Bush | Direct sun (at least 4-6 hours) | Keep substrate consistently moist but not waterlogged; water every 2–4 days depending on conditions | Pet-safe |
| Fly Orchid | Bright indirect light (just back from a sunny window) | Seasonal; moist in spring, drier in summer dormancy | Mildly toxic to pets |
| Fly-catching Restrepia | Medium indirect light (a couple of metres from a window) | Every 2–4 days; allow the surface to barely begin to dry | Pet-safe |
| Foamy Bells 'Sweet Tea' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Foothill Penstemon 'Margarita BOP' | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-21 days during the growing season | Mildly toxic to pets |
| Forbes' Glory of the Snow | Bright indirect light (just back from a sunny window) | Relies on natural rainfall during its growing season; water lightly if spring is unusually dry | Toxic to pets |
| Forest Elephant's Foot | Bright indirect light (just back from a sunny window) | Every 1–2 weeks during active growth (autumn to spring); withhold almost entirely in summer dormancy | Mildly toxic to pets |
| Forest Flame pieris | Bright indirect light (just back from a sunny window) | Weekly during dry periods | Toxic to pets |
| Forest Flame Pieris | Bright indirect light (just back from a sunny window) | Every 7-10 days in the growing season; established plants roughly every 10-14 days, more frequently during dry spells | Toxic to pets |
| Forest Spurflower | Medium indirect light (a couple of metres from a window) | Every 7-10 days in the growing season; every 14-21 days in winter | Mildly toxic to pets |
| Forget-me-not | Medium indirect light (a couple of metres from a window) | Weekly watering | Pet-safe |
| Fork-leaved Sundew | Direct sun (at least 4-6 hours) | Keep permanently wet; stand the pot in 1-3 cm of water at all times | Mildly toxic to pets |
| Forked Aichryson | Bright indirect light (just back from a sunny window) | Every 10–14 days during active growth; reduced in winter rest | Mildly toxic to pets |
| Forked Spleenwort | Medium indirect light (a couple of metres from a window) | Sparingly — water only when the growing medium is dry | Mildly toxic to pets |
| Forked Sundew | Direct sun (at least 4-6 hours) | Sit in 1–3 cm of standing water at all times during the growing season; reduce to barely moist during winter dormancy | Mildly toxic to pets |
| Forking larkspur | Direct sun (at least 4-6 hours) | Every 5–8 days | Toxic to pets |
| Formosa Lily | Direct sun (at least 4-6 hours) | 2-3 times per week in active growth | Toxic to pets |
| Formosanum Toad Lily | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water when the top of the soil begins to dry, often twice weekly in summer heat | Mildly toxic to pets |
| Forrest Fir | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry for young trees, roughly every 10-14 days during establishment | Mildly toxic to pets |
| Forrest Ginger Lily | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Forrest's Ginger Lily | Bright indirect light (just back from a sunny window) | Generously and consistently through spring and summer | Mildly toxic to pets |
| Forrest's pieris | Bright indirect light (just back from a sunny window) | Regular; do not allow to dry out | Toxic to pets |
| Forrests Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growth; very sparingly in winter | Pet-safe |
| Forsythia 'Lynwood Gold' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in extended dry spells | Pet-safe |
| Forsythia 'Show Off' | Direct sun (at least 4-6 hours) | Weekly to establish, then mainly during dry spells | Pet-safe |
| Forsythia Sage | Bright indirect light (just back from a sunny window) | Weekly during active growth | Pet-safe |
| Fortune Plum Yew | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, roughly every 10-14 days in the growing season | Toxic to pets |
| Fortune's Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Fortune's Holly Fern | Medium indirect light (a couple of metres from a window) | Every 7–10 days; allow top few centimetres to dry between waterings | Mildly toxic to pets |
| Fortune's Holly Fern | Low light (north window or shaded room) | When the top 2-3 cm of soil feels dry, roughly every 7-10 days in summer and every 10-14 days in winter | Pet-safe |
| Fothergilla 'Mount Airy' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly weekly while establishing | Mildly toxic to pets |
| Fothergilla gardenii | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly weekly while establishing | Mildly toxic to pets |
| Fothergilla major | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly while establishing | Mildly toxic to pets |
| Four-Leaf Water Clover | Bright indirect light (just back from a sunny window) | Aquatic — grows in shallow water or moist substrate permanently | Pet-safe |
| Four-stamen Tamarisk | Direct sun (at least 4-6 hours) | Moderate to low; drought-tolerant once established | Pet-safe |
| Fourth of July Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, more during heat | Pet-safe |
| Foxglove | Bright indirect light (just back from a sunny window) | Regularly — weekly in summer, less in winter | Toxic to pets |
| Foxglove 'Camelot' | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water weekly in dry weather | Toxic to pets |
| Foxglove beardtongue | Direct sun (at least 4-6 hours) | Every 7–10 days during establishment; drought-tolerant once established | Mildly toxic to pets |
| Foxglove Sage | Bright indirect light (just back from a sunny window) | Regular — keep soil evenly moist but not saturated | Mildly toxic to pets |
| Foxtail Palm | Direct sun (at least 4-6 hours) | When the top few cm of soil dries; regularly in growth | Mildly toxic to pets |
| Foxtail Pine | Direct sun (at least 4-6 hours) | Deep soak every 2-3 weeks once established; let soil dry between waterings | Mildly toxic to pets |
| Fragrant Bouquet Hosta | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water deeply 1-2 times weekly, more in heat | Toxic to pets |
| Fragrant Bursera | Direct sun (at least 4-6 hours) | Every 7–10 days in summer growing season; very sparingly in winter | Mildly toxic to pets |
| Fragrant Hosta 'Guacamole' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, about every 5-7 days; more in sun and heat | Toxic to pets |
| Fragrant Orchid | Direct sun (at least 4-6 hours) | Very low to low — rain-fed only | Mildly toxic to pets |
| Fragrant Stomatium | Bright indirect light (just back from a sunny window) | Sparingly in summer; every 2–3 weeks in autumn–spring | Pet-safe |
| Fragrant Sweet Box | Low light (north window or shaded room) | Every 10-14 days during establishment; established plants are very drought-tolerant and require watering only during prolonged dry periods | Mildly toxic to pets |
| Fragrant Water Lily | Direct sun (at least 4-6 hours) | Aquatic — permanently grown in standing water | Toxic to pets |
| Francee Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Franchet Cotoneaster | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Franklin's Gem Boxwood | Direct sun (at least 4-6 hours) | Deep soak weekly during the first two seasons, then every 10-14 days in dry spells | Toxic to pets |
| Franz's Living Stone | Direct sun (at least 4-6 hours) | Every 2-4 weeks in the summer growing season; completely dry from mid-autumn to late spring | Pet-safe |
| Fraser Fir | Direct sun (at least 4-6 hours) | Regularly; moist but well-drained | Mildly toxic to pets |
| Frau Dagmar Hartopp Rose | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant once settled | Pet-safe |
| Fred Ives | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring/summer; every 3–4 weeks in winter | Pet-safe |
| Free-Flowering Cymbidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; every 10 days in winter | Pet-safe |
| Freesia | Direct sun (at least 4-6 hours) | Keep evenly moist while in growth; reduce to nothing once foliage yellows after flowering | Pet-safe |
| Freesia 'Pink Marble' | Direct sun (at least 4-6 hours) | Water regularly once shoots appear, roughly every 4-7 days, keeping soil moist but not wet | Pet-safe |
| Freesia 'Royal Blue' | Direct sun (at least 4-6 hours) | Water every 4-7 days during active growth, keeping the soil evenly moist but never waterlogged | Pet-safe |
| Freesia 'Yellow Passion' | Direct sun (at least 4-6 hours) | Water every 4-7 days while in growth, keeping soil moist but not soggy | Pet-safe |
| Freesia refracta | Direct sun (at least 4-6 hours) | Water every 5-7 days during winter-spring growth, keeping the soil just moist | Pet-safe |
| French Tamarisk | Direct sun (at least 4-6 hours) | Moderate; drought-tolerant once established | Pet-safe |
| Freyn's Pink | Direct sun (at least 4-6 hours) | Infrequent; drought-tolerant once established | Mildly toxic to pets |
| Friedrich's Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn; none during summer dormancy | Pet-safe |
| Friedrich's Window Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in autumn and spring; minimal to none in summer | Mildly toxic to pets |
| Fringed Cliff Stonecrop | Direct sun (at least 4-6 hours) | Every 14–21 days in the growing season; minimal in winter | Pet-safe |
| Fringed Coelogyne | Medium indirect light (a couple of metres from a window) | Every 7-10 days in the growing season; every 14-21 days in cooler months | Pet-safe |
| Fringed Miniature Stelis | Medium indirect light (a couple of metres from a window) | Daily or near-daily; roots must not dry completely between watering | Pet-safe |
| Fringed Spurflower | Medium indirect light (a couple of metres from a window) | Regularly — keep soil evenly moist throughout the growing season | Mildly toxic to pets |
| Fringed Stelis | Medium indirect light (a couple of metres from a window) | Every 1–3 days depending on mount or medium and ambient temperature | Pet-safe |
| Fringed-sepal Primulina | Medium indirect light (a couple of metres from a window) | Reduced in winter; moderate in spring and summer | Mildly toxic to pets |
| Fritillaria imperialis 'Lutea' | Direct sun (at least 4-6 hours) | Moderate moisture in spring growth; keep the dormant bulb dry in summer | Mildly toxic to pets |
| Fritillaria meleagris | Direct sun (at least 4-6 hours) | Keep soil moist through spring growth; tolerates damp ground | Mildly toxic to pets |
| Frohnleiten Epimedium | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 1-2 weeks | Mildly toxic to pets |
| Fuchsia 'Alice Hoffman' | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil or compost are dry, roughly every 7-10 days | Pet-safe |
| Fuchsia 'Annabel' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost are dry, roughly every 5-7 days in summer | Pet-safe |
| Fuchsia 'Beacon' | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil or compost are dry, roughly every 7-10 days in summer | Pet-safe |
| Fuchsia 'Brutus' | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil or compost are dry, roughly every 7-10 days | Pet-safe |
| Fuchsia 'Cardinal Farges' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil are dry, roughly every 8-12 days when established | Pet-safe |
| Fuchsia 'Celia Smedley' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 3-5 days in summer | Mildly toxic to pets |
| Fuchsia 'Checkerboard' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feels dry, roughly every 3-5 days in summer | Mildly toxic to pets |
| Fuchsia 'Dark Eyes' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 2-4 days in summer baskets | Mildly toxic to pets |
| Fuchsia 'Dollar Princess' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feels dry, roughly every 5-7 days in summer | Pet-safe |
| Fuchsia 'Gartenmeister Bonstedt' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, roughly every 3-5 days in warm weather | Pet-safe |
| Fuchsia 'Golden Marinka' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 5-7 days in summer | Pet-safe |
| Fuchsia 'Lady Thumb' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 5-7 days in active growth | Pet-safe |
| Fuchsia 'Marinka' | Bright indirect light (just back from a sunny window) | When the top 2 cm of compost are dry, roughly every 5-7 days; daily checks in hot weather | Pet-safe |
| Fuchsia 'Mrs Popple' | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil or compost is dry, roughly every 3-5 days during active growth | Pet-safe |
| Fuchsia 'Papoose' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feels dry, roughly every 3-5 days in summer | Mildly toxic to pets |
| Fuchsia 'Phyllis' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feels dry, roughly every 4-6 days in summer | Mildly toxic to pets |
| Fuchsia 'Pink Marshmallow' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost feel dry, roughly every 5-7 days; more frequently in summer heat | Pet-safe |
| Fuchsia 'Red Spider' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost are dry, roughly every 5-7 days in summer | Pet-safe |
| Fuchsia 'Snowcap' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 3-5 days in the growing season | Mildly toxic to pets |
| Fuchsia 'Swingtime' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of compost is dry, roughly every 2-3 days in warm weather | Pet-safe |
| Fuchsia 'Thalia' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of compost is dry, roughly every 3-5 days in warm weather | Pet-safe |
| Fuchsia 'Tom Thumb' | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil or compost feels dry, roughly every 5-8 days | Pet-safe |
| Fuchsia 'Voodoo' | Bright indirect light (just back from a sunny window) | When the top 2 cm of compost are dry, roughly every 5-7 days in summer | Pet-safe |
| Fuchsia 'Winston Churchill' | Bright indirect light (just back from a sunny window) | When the top 2 cm of compost are dry, roughly every 6-8 days | Pet-safe |
| Fuchsia magellanica | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 3-5 days in summer heat | Pet-safe |
| Fujian Cypress | Bright indirect light (just back from a sunny window) | Once or twice a week during the growing season; reduce in winter | Mildly toxic to pets |
| Full Moon Maple | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly weekly in summer | Pet-safe |
| Fuller's Living Stone | Direct sun (at least 4-6 hours) | Only when the old lobe pair is fully shrivelled (summer dormancy) and during the active growing window autumn–spring; roughly every 14-21 days when active | Pet-safe |
| Fuller's Stomatium | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; every 4-6 weeks or less in winter | Mildly toxic to pets |
| Fuller's Titanopsis | Direct sun (at least 4-6 hours) | Every 3–4 weeks in autumn/winter growing season; minimal in summer dormancy | Pet-safe |
| Fuller's Titanopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks during autumn to early spring; barely once a month in summer dormancy | Pet-safe |
| Furuse's Orostachys | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; minimal watering in winter | Pet-safe |
| Furzey Darley Dale heath | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Fused Tooth Venus flytrap | Direct sun (at least 4-6 hours) | Continuously moist via tray method during growing season; damp only in dormancy | Pet-safe |
| Gaillardia 'Burgundy' | Direct sun (at least 4-6 hours) | Once or twice a week during the first season; once every 2 weeks or less when established | Mildly toxic to pets |
| Gaillardia 'Dazzler' | Direct sun (at least 4-6 hours) | Once or twice a week in year one; once every 2 weeks or less once established | Mildly toxic to pets |
| Gaillardia 'Fanfare' | Direct sun (at least 4-6 hours) | Once a week during establishment; every 14 days or less once established in the ground | Mildly toxic to pets |
| Gaillardia 'Mesa Red' | Direct sun (at least 4-6 hours) | Once or twice weekly during establishment; once every 14 days or less when established | Mildly toxic to pets |
| Gaillardia 'Mesa Yellow' | Direct sun (at least 4-6 hours) | Once or twice a week during establishment; every 14 days or less when established | Mildly toxic to pets |
| Gaillardia 'SpinTop Orange Halo' | Direct sun (at least 4-6 hours) | Once or twice a week during establishment; once every 10–14 days when established; check containers every 3–4 days in summer | Mildly toxic to pets |
| Gaillardia 'Sun Devil' | Direct sun (at least 4-6 hours) | Every 10-14 days once established; drought-tolerant | Mildly toxic to pets |
| Gaillardia 'Tizzy' | Direct sun (at least 4-6 hours) | Once a week during establishment; every 14 days or less when established in the ground; check every 3–5 days in containers | Mildly toxic to pets |
| Gaillardia 'Torchlight' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days in summer; reduce sharply in winter | Mildly toxic to pets |
| Garden Phlox | Bright indirect light (just back from a sunny window) | 1-2 times per week during active growth | Mildly toxic to pets |
| Garden Phlox 'David' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 5-7 days | Pet-safe |
| Garden Phlox 'David' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Garden Pink 'Mrs Sinkins' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Garden verbena | Direct sun (at least 4-6 hours) | Every 3–5 days during active growth; reduce in cooler weather | Mildly toxic to pets |
| Garden's Clivia | Bright indirect light (just back from a sunny window) | Water freely in spring and summer; reduce to minimal in autumn and winter. | Toxic to pets |
| Gargoyle Lepanthes | Medium indirect light (a couple of metres from a window) | Every 1–2 days; medium should be moist but not sodden | Pet-safe |
| Gasteria (Ox Tongue) | Bright indirect light (just back from a sunny window) | Every 2-3 weeks in spring/summer; roughly monthly or less in autumn/winter | Mildly toxic to pets |
| Gasteria Nitida | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in growth | Pet-safe |
| Gaura 'Siskiyou Pink' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days during the growing season | Pet-safe |
| Geisha Girl flowering quince | Bright indirect light (just back from a sunny window) | Weekly during establishment; occasional supplemental watering once established | Mildly toxic to pets |
| Gentian Sage | Direct sun (at least 4-6 hours) | Moderate; water when the top 2–3 cm of soil dries out | Pet-safe |
| Gentle Hermione Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week during the growing season; more in heat | Pet-safe |
| Georgia Blue Speedwell | Direct sun (at least 4-6 hours) | Moderate; water when the top 2–3 cm of soil dries out | Pet-safe |
| Geranium 'Ann Folkard' | Direct sun (at least 4-6 hours) | Weekly while establishing and in dry spells; little once mature. | Mildly toxic to pets |
| Geranium 'Brookside' | Direct sun (at least 4-6 hours) | Weekly while establishing and in droughts; minimal once settled. | Mildly toxic to pets |
| Geranium 'Johnson's Blue' | Direct sun (at least 4-6 hours) | Water to establish in the first season; thereafter when the top few cm of soil is dry, roughly weekly in dry spells | Pet-safe |
| Geranium 'Nimbus' | Direct sun (at least 4-6 hours) | Weekly while establishing and during dry spells; drought-tolerant when mature | Mildly toxic to pets |
| Geranium 'Orion' | Direct sun (at least 4-6 hours) | Weekly while establishing and in dry spells; drought-tolerant once mature | Mildly toxic to pets |
| Geranium 'Patricia' | Direct sun (at least 4-6 hours) | Water when the top 3-4 cm dries, roughly weekly in growing season; established clumps tolerate some dryness | Mildly toxic to pets |
| Geranium × oxonianum 'Wargrave Pink' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry; roughly weekly, more in heat | Mildly toxic to pets |
| Geranium cantabrigiense | Direct sun (at least 4-6 hours) | Weekly while establishing; very little once settled. | Mildly toxic to pets |
| Geranium cantabrigiense 'Biokovo' | Direct sun (at least 4-6 hours) | Weekly while establishing; very little thereafter. | Mildly toxic to pets |
| Geranium cantabrigiense 'Cambridge' | Bright indirect light (just back from a sunny window) | Water deeply during the first season; established plants need watering only in prolonged drought | Mildly toxic to pets |
| Geranium cinereum 'Ballerina' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil are dry; sparingly once established | Mildly toxic to pets |
| Geranium cinereum 'Lawrence Flatman' | Direct sun (at least 4-6 hours) | When the top few centimetres are dry; keep on the dry side once established | Mildly toxic to pets |
| Geranium cinereum var. subcaulescens | Direct sun (at least 4-6 hours) | When the top few centimetres of soil are dry; sparingly once established | Mildly toxic to pets |
| Geranium clarkei 'Kashmir Purple' | Direct sun (at least 4-6 hours) | Weekly while establishing and in droughts; drought-tolerant once settled | Mildly toxic to pets |
| Geranium clarkei 'Kashmir White' | Direct sun (at least 4-6 hours) | Weekly while establishing and in droughts; drought-tolerant once settled | Mildly toxic to pets |
| Geranium endressii | Bright indirect light (just back from a sunny window) | Water through establishment; afterwards in dry spells only | Mildly toxic to pets |
| Geranium himalayense | Direct sun (at least 4-6 hours) | Weekly during the first season and in dry spells; established plants are drought-tolerant | Mildly toxic to pets |
| Geranium himalayense 'Gravetye' | Direct sun (at least 4-6 hours) | Weekly while establishing and during droughts; drought-tolerant once rooted | Mildly toxic to pets |
| Geranium himalayense 'Plenum' | Direct sun (at least 4-6 hours) | Weekly while establishing and in drought; otherwise drought-tolerant once settled | Mildly toxic to pets |
| Geranium macrorrhizum | Medium indirect light (a couple of metres from a window) | Water to establish; afterwards only in extended drought, roughly every 1-2 weeks if very dry | Pet-safe |
| Geranium macrorrhizum 'Bevan's Variety' | Medium indirect light (a couple of metres from a window) | When the top 4-5 cm of soil is dry; weekly to establish, seldom afterwards | Mildly toxic to pets |
| Geranium macrorrhizum 'Spessart' | Bright indirect light (just back from a sunny window) | Water deeply when top 5 cm of soil is dry; established plants need little to no supplemental water | Mildly toxic to pets |
| Geranium maculatum | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply when the top 3-4 cm dries, roughly weekly in the growing season | Mildly toxic to pets |
| Geranium maculatum 'Elizabeth Ann' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply when the top 3-4 cm dries, about weekly during the growing season | Mildly toxic to pets |
| Geranium nodosum | Low light (north window or shaded room) | Water when the top 3-5 cm dries; established plants tolerate occasional dryness, roughly every 7-12 days in growing season | Mildly toxic to pets |
| Geranium phaeum | Medium indirect light (a couple of metres from a window) | Water when top 3-5 cm of soil is dry; keep evenly moist in its first season | Mildly toxic to pets |
| Geranium phaeum 'Album' | Medium indirect light (a couple of metres from a window) | Water when top 3-5 cm of soil is dry; keep evenly moist while establishing | Mildly toxic to pets |
| Geranium phaeum 'Lily Lovell' | Medium indirect light (a couple of metres from a window) | Water when top 3-5 cm of soil is dry; keep evenly moist while establishing | Mildly toxic to pets |
| Geranium phaeum 'Samobor' | Medium indirect light (a couple of metres from a window) | Water when top 3-5 cm of soil is dry; keep evenly moist while establishing | Mildly toxic to pets |
| Geranium pratense | Direct sun (at least 4-6 hours) | Roughly weekly in the first season and during prolonged dry spells; established plants need little. | Mildly toxic to pets |
| Geranium pratense 'Mrs Kendall Clark' | Direct sun (at least 4-6 hours) | About weekly while establishing and in dry spells; little once settled. | Mildly toxic to pets |
| Geranium pratense 'Plenum Violaceum' | Direct sun (at least 4-6 hours) | Weekly while establishing and during droughts; minimal once mature. | Mildly toxic to pets |
| Geranium pratense 'Victor Reiter Junior' | Direct sun (at least 4-6 hours) | Weekly while establishing and in dry spells; sparing once settled. | Mildly toxic to pets |
| Geranium psilostemon | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; about weekly, more in heat | Mildly toxic to pets |
| Geranium renardii | Direct sun (at least 4-6 hours) | Water when the top 4-5 cm dries; drought-tolerant once established, roughly every 10-14 days in growing season | Mildly toxic to pets |
| Geranium renardii 'Phillipe Vapelle' | Direct sun (at least 4-6 hours) | Water when the top 4-5 cm dries; drought-tolerant once established, roughly every 10-14 days in growing season | Mildly toxic to pets |
| Geranium sanguineum | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; weekly while establishing, infrequently once mature | Mildly toxic to pets |
| Geranium sanguineum 'Album' | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil is dry; established plants are drought-tolerant | Mildly toxic to pets |
| Geranium sanguineum 'Max Frei' | Direct sun (at least 4-6 hours) | Water when top 3-5 cm of soil is dry; drought-tolerant once established | Mildly toxic to pets |
| Geranium sanguineum var. striatum | Direct sun (at least 4-6 hours) | Water when top 3-5 cm of soil is dry; drought-tolerant once established | Mildly toxic to pets |
| Geranium sylvaticum | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water deeply when the top 3-4 cm dries, roughly weekly in growing season | Mildly toxic to pets |
| Geranium sylvaticum 'Mayflower' | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply when the top 3-4 cm dries, about weekly through the growing season | Mildly toxic to pets |
| Geranium wallichianum 'Buxton's Variety' | Bright indirect light (just back from a sunny window) | Water during establishment, then keep just-moist through summer; little needed in winter dormancy | Mildly toxic to pets |
| Geranium wallichianum 'Syabru' | Bright indirect light (just back from a sunny window) | Water during establishment, then keep evenly moist through the growing season | Mildly toxic to pets |
| Geranium x magnificum | Direct sun (at least 4-6 hours) | Weekly in the first season and during drought; established plants are fairly drought-tolerant | Mildly toxic to pets |
| Geranium x oxonianum | Bright indirect light (just back from a sunny window) | Water through the first season; thereafter only during sustained dry spells | Mildly toxic to pets |
| Geranium x oxonianum 'A.T. Johnson' | Bright indirect light (just back from a sunny window) | Water through establishment; thereafter only in prolonged dry spells | Mildly toxic to pets |
| Geranium x oxonianum 'Claridge Druce' | Bright indirect light (just back from a sunny window) | Water during the first season; afterwards only in extended drought | Mildly toxic to pets |
| Geranium x oxonianum 'Wargrave Pink' | Bright indirect light (just back from a sunny window) | Water during establishment; afterwards only in extended drought | Mildly toxic to pets |
| German Empress Orchid Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm is dry, roughly every 7-10 days in growth | Pet-safe |
| Germander Speedwell | Medium indirect light (a couple of metres from a window) | Moderate — keep soil consistently moist, especially in summer | Pet-safe |
| Gertrude Jekyll Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat or sandy soil | Pet-safe |
| Gesine's Living Stone | Direct sun (at least 4-6 hours) | Approximately every 14-21 days during the autumn-spring active period only; none in summer dormancy | Pet-safe |
| Gesneria-flowered Sage | Direct sun (at least 4-6 hours) | Regular during the growing season | Pet-safe |
| Geum 'Mrs Bradshaw' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; keep evenly moist in summer | Mildly toxic to pets |
| Geum 'Prinses Juliana' | Direct sun (at least 4-6 hours) | Keep soil moist but not waterlogged; water every 4-7 days in dry weather | Mildly toxic to pets |
| Geum 'Scarlet Tempest' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; keep evenly moist in summer | Mildly toxic to pets |
| Geum 'Totally Tangerine' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply every 5-7 days in dry spells | Mildly toxic to pets |
| Geum rivale 'Leonard's Variety' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in dry spells, more in containers | Mildly toxic to pets |
| Geyer's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during active growth (autumn to early spring); none in summer | Pet-safe |
| Ghost Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season, reduce in winter | Pet-safe |
| Giant Autumn Daffodil | Direct sun (at least 4-6 hours) | Minimal water during autumn–spring growth; bone dry in summer | Toxic to pets |
| Giant Barrel Cactus | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer; rarely or not at all in winter | Mildly toxic to pets |
| Giant Bellflower | Medium indirect light (a couple of metres from a window) | Regularly — keep soil consistently moist throughout the growing season | Pet-safe |
| Giant Chain Fern | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil begins to dry, roughly every 5-8 days in summer | Pet-safe |
| Giant Chalk Dudleya | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer, monthly or less in winter | Pet-safe |
| Giant Chalk Dudleya | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14–21 days in summer and every 4–6 weeks in winter | Mildly toxic to pets |
| Giant Chin Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-14 days in summer; every 4-6 weeks in winter | Pet-safe |
| Giant Chincherinchee | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days during active growth | Toxic to pets |
| Giant Chinese Silver Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; moderate, regular water thereafter | Mildly toxic to pets |
| Giant Cymbidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce in winter rest | Pet-safe |
| Giant Dioon | Bright indirect light (just back from a sunny window) | Every 1–2 weeks in summer; every 3–4 weeks in winter | Toxic to pets |
| Giant Dogwood | Bright indirect light (just back from a sunny window) | Weekly deep watering for young trees; deep watering in droughts for mature specimens | Pet-safe |
| Giant Feather Grass | Direct sun (at least 4-6 hours) | Every 7-10 days in the first season while establishing, then rarely | Mildly toxic to pets |
| Giant Fishtail Palm | Direct sun (at least 4-6 hours) | Regularly; keep soil moderately moist | Mildly toxic to pets |
| Giant Hard Fern | Medium indirect light (a couple of metres from a window) | 2-3 times per week in growing season; reduce in winter | Pet-safe |
| Giant honeysuckle | Direct sun (at least 4-6 hours) | Twice weekly in active growth; reduce significantly in cooler months | Mildly toxic to pets |
| Giant Maidenhair Fern | Medium indirect light (a couple of metres from a window) | Every 3–4 days in active growth; every 5–7 days in winter | Pet-safe |
| Giant Mondo Grass | Bright indirect light (just back from a sunny window) | Water when the top 2–3 cm of soil is dry, approximately every 7–10 days in the growing season | Mildly toxic to pets |
| Giant Montbretia | Direct sun (at least 4-6 hours) | Every 7-10 days in the growing season; reduce to occasional watering once foliage yellows in autumn | Mildly toxic to pets |
| Giant Phragmipedium | Bright indirect light (just back from a sunny window) | Keep consistently moist — water when the surface of the medium is barely dry | Pet-safe |
| Giant Pineapple Lily | Direct sun (at least 4-6 hours) | Regular during the growing season; minimal in winter dormancy | Toxic to pets |
| Giant Pineapple Lily | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry during active growth, roughly every 7-14 days | Toxic to pets |
| Giant Rainbow Plant | Direct sun (at least 4-6 hours) | Water freely in the wet season (winter/spring); drastically reduce and allow near-drying in summer | Pet-safe |
| Giant Sequoia | Direct sun (at least 4-6 hours) | Weekly while establishing; deep occasional soaks once mature | Mildly toxic to pets |
| Giant Sequoia 'Blauer Eichzwerg' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry; keep evenly moist, every 7-10 days | Mildly toxic to pets |
| Giant Sequoia 'Glaucum' | Direct sun (at least 4-6 hours) | Deeply once or twice a week while establishing; then during dry spells | Mildly toxic to pets |
| Giant Snowdrop | Bright indirect light (just back from a sunny window) | Regular moisture during growth; tolerates drier summer dormancy than G. nivalis | Toxic to pets |
| Giant Snowflake Bacopa | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of potting mix feels dry, roughly every 3-5 days in warm weather | Pet-safe |
| Giant Thevetia | Direct sun (at least 4-6 hours) | Every 7–14 days once established; water deeply during the growing season | Toxic to pets |
| Giant Timber Bamboo | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week; more frequently in hot weather or during shooting season | Pet-safe |
| Giant Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist spring through early summer; tolerates drier conditions once fully summer-dormant. | Mildly toxic to pets |
| Giant Typhonium | Medium indirect light (a couple of metres from a window) | Regularly during the growing season; reduce through autumn and winter | Toxic to pets |
| Giant Wild Pine | Bright indirect light (just back from a sunny window) | Weekly soak or twice-weekly misting | Pet-safe |
| Gibbaeum album | Bright indirect light (just back from a sunny window) | Lightly in autumn through spring during growth; keep nearly dry in summer | Mildly toxic to pets |
| Gibbaeum heathii | Direct sun (at least 4-6 hours) | Sparingly in autumn-spring growth; near-zero through summer dormancy | Mildly toxic to pets |
| Gibbaeum petrense | Direct sun (at least 4-6 hours) | Light watering in autumn-spring; withhold through summer | Mildly toxic to pets |
| Gibbaeum velutinum | Direct sun (at least 4-6 hours) | Moderate in autumn-spring; minimal in summer | Mildly toxic to pets |
| Ginkgo 'Autumn Gold' | Direct sun (at least 4-6 hours) | Regularly for the first 2-3 years; drought-tolerant once established | Mildly toxic to pets |
| Ginkgo 'Fastigiata' | Direct sun (at least 4-6 hours) | Weekly while establishing in the first 1-2 years; rarely once mature | Mildly toxic to pets |
| Ginkgo 'Mariken' | Direct sun (at least 4-6 hours) | Weekly when young or container-grown; occasionally once established in ground | Mildly toxic to pets |
| Ginkgo 'Saratoga' | Direct sun (at least 4-6 hours) | Weekly during establishment; minimal once mature | Mildly toxic to pets |
| Glacier Pink | Direct sun (at least 4-6 hours) | Low; water very sparingly, letting the soil nearly dry out between waterings | Mildly toxic to pets |
| Gladiolus 'Espresso' | Direct sun (at least 4-6 hours) | Keep evenly moist during growth, roughly 25 mm per week and more during spike formation | Toxic to pets |
| Gladiolus 'Impressive' | Direct sun (at least 4-6 hours) | Keep evenly moist during growth, roughly 25 mm per week in dry spells | Toxic to pets |
| Gladiolus 'Purple Flora' | Direct sun (at least 4-6 hours) | Keep evenly moist in growth, about 25 mm per week, more in heat and as spikes form | Toxic to pets |
| Glandular Heron's Bill | Direct sun (at least 4-6 hours) | Water sparingly; allow soil to dry almost completely between waterings | Mildly toxic to pets |
| Glandular Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; very sparingly or not at all in winter | Pet-safe |
| Glandular-stemmed Monanthes | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring and summer; monthly in winter | Mildly toxic to pets |
| Glaucous Lampranthus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer growing season; every 4–6 weeks in winter | Mildly toxic to pets |
| Glaziou's Fuchsia | Bright indirect light (just back from a sunny window) | Water freely in growth; reduce in winter | Pet-safe |
| Gleditsia triacanthos 'Sunburst' | Direct sun (at least 4-6 hours) | Water weekly for the first two seasons; established trees are notably drought-tolerant | Pet-safe |
| Gleditsia triacanthos f. inermis | Direct sun (at least 4-6 hours) | Water weekly for the first two seasons; established trees are highly drought-tolerant | Pet-safe |
| Globe candytuft | Direct sun (at least 4-6 hours) | Every 7–10 days; keep evenly moist but not waterlogged | Pet-safe |
| Gloriosa Daisy | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out; about weekly, more in heat | Mildly toxic to pets |
| Glory of Texas Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer and once every 5-6 weeks in winter | Pet-safe |
| Glory of the Snow | Bright indirect light (just back from a sunny window) | Low; relies on natural rainfall in most temperate gardens | Mildly toxic to pets |
| Glory of the Sun | Direct sun (at least 4-6 hours) | Moderate in growth; completely dry in summer dormancy | Mildly toxic to pets |
| Glossy Abelia | Direct sun (at least 4-6 hours) | Regularly during the first growing season; occasional deep watering once established | Pet-safe |
| Glyceria maxima 'Variegata' | Direct sun (at least 4-6 hours) | Keep constantly moist to shallowly submerged | Toxic to pets |
| Gnome Spruce | Direct sun (at least 4-6 hours) | Every 5-7 days; water when the surface of the small root zone dries | Pet-safe |
| Goat's Horn Cactus | Direct sun (at least 4-6 hours) | When the soil is bone dry, every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Goat's-beard | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Mildly toxic to pets |
| Goehring's Dyckia | Direct sun (at least 4-6 hours) | When the compost is completely dry, roughly every 14-21 days in growing season | Pet-safe |
| Gold Coast Juniper | Direct sun (at least 4-6 hours) | Water deeply through the first season; thereafter mainly in prolonged drought | Toxic to pets |
| Gold Dew Tufted Hair Grass | Bright indirect light (just back from a sunny window) | Moderate to frequent — prefers consistently moist soil | Pet-safe |
| Gold Dust Alyssum | Direct sun (at least 4-6 hours) | Fortnightly to monthly once established (very drought-tolerant) | Pet-safe |
| Gold Heart Bleeding Heart | Medium indirect light (a couple of metres from a window) | Weekly during the growing season, reducing as foliage dies back in summer | Toxic to pets |
| Gold Mound Spirea | Direct sun (at least 4-6 hours) | Weekly when establishing; every 1–2 weeks once established | Pet-safe |
| Gold Plate yarrow | Direct sun (at least 4-6 hours) | Every 1–2 weeks once established; more frequent during establishment | Mildly toxic to pets |
| Gold Rush Dawn Redwood | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days in summer | Mildly toxic to pets |
| Gold Tooth Aloe | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in growth | Toxic to pets |
| Golden Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (soil evenly moist; never waterlogged) | Toxic to pets |
| Golden Arch Dendrobium | Bright indirect light (just back from a sunny window) | Every 5-7 days in active growth; reduce to every 3-4 weeks in winter | Pet-safe |
| Golden Ash | Direct sun (at least 4-6 hours) | Moderate; regular deep watering when establishing | Pet-safe |
| Golden Bamboo | Direct sun (at least 4-6 hours) | Weekly when establishing; drought-tolerant once established | Pet-safe |
| Golden Barrel Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Golden Cinquefoil | Direct sun (at least 4-6 hours) | Every 10–14 days; drought-tolerant once established | Pet-safe |
| Golden Cliff Stonecrop | Direct sun (at least 4-6 hours) | Every 10–14 days in spring and autumn; monthly in summer; very sparingly in winter | Pet-safe |
| Golden Club | Direct sun (at least 4-6 hours) | Permanently aquatic; plant crown 10–15 cm (4–6 in) below the water surface | Mildly toxic to pets |
| Golden Crocus | Direct sun (at least 4-6 hours) | Minimal supplemental water needed; relies on natural rainfall; ensure summer-dry conditions for corm dormancy | Mildly toxic to pets |
| Golden Deodar Cedar | Direct sun (at least 4-6 hours) | Moderately; regularly during establishment, infrequently once mature | Mildly toxic to pets |
| Golden Deodar Cedar | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in the growing season | Mildly toxic to pets |
| Golden Easter Lily Cactus | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is completely dry, roughly every 10-14 days in the growing season; once a month or less in winter. | Pet-safe |
| Golden Eriosyce | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is completely dry, every 10-14 days in summer | Pet-safe |
| Golden everlasting | Direct sun (at least 4-6 hours) | Every 7–10 days once established; reduce in autumn | Pet-safe |
| golden fescue | Direct sun (at least 4-6 hours) | Low; water every 10–14 days during the growing season, less in winter | Pet-safe |
| Golden Globe Arborvitae | Direct sun (at least 4-6 hours) | Twice weekly while establishing; weekly thereafter | Mildly toxic to pets |
| Golden Goddess Bamboo | Direct sun (at least 4-6 hours) | Twice weekly during dry periods in summer; reduce to weekly or less in cooler seasons | Pet-safe |
| Golden Ice Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks (allow soil to dry completely between waterings) | Pet-safe |
| Golden Japanese Sweet Flag | Bright indirect light (just back from a sunny window) | Keep the soil constantly moist to wet; water as soon as the surface begins to dry, often every 2-4 days | Mildly toxic to pets |
| Golden Japanese Sweet Flag | Medium indirect light (a couple of metres from a window) | Keep constantly moist; tolerate standing water | Pet-safe |
| Golden Rat Tail Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer and every 3-4 weeks in winter | Pet-safe |
| Golden Sedum | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; every 3–4 weeks in winter | Pet-safe |
| Golden Star Cactus | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Golden Tree Fern | Bright indirect light (just back from a sunny window) | 2-3 times per week; trunk must stay moist | Pet-safe |
| Golden Tree Fern | Bright indirect light (just back from a sunny window) | Keep consistently moist; water when the top 3-5 cm of soil feels dry or when trunk feels dry to the touch, roughly every 3-7 days in summer | Pet-safe |
| Golden-Edged Cymbidium | Bright indirect light (just back from a sunny window) | Keep evenly moist in growth, about every 5-7 days, drier in winter | Pet-safe |
| Golden-Flowered Ginger | Bright indirect light (just back from a sunny window) | Keep evenly moist during the growing season; reduce after die-back. | Mildly toxic to pets |
| Golden-flowered Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the growing season; minimally in winter | Pet-safe |
| Golden-Hair Bamboo | Bright indirect light (just back from a sunny window) | Twice per week in growing season; once per week or less in winter | Pet-safe |
| Golden-Leaved Jerusalem Sage | Direct sun (at least 4-6 hours) | Low — water every 2–3 weeks in summer; keep dry in winter | Mildly toxic to pets |
| Golden-rayed Lily | Direct sun (at least 4-6 hours) | When top 3 cm of soil is dry | Toxic to pets |
| Golden-spike Disa | Bright indirect light (just back from a sunny window) | Keep consistently moist throughout the year, roughly every 2-4 days | Pet-safe |
| Goldenrod | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Goldmoss Stonecrop | Direct sun (at least 4-6 hours) | Rarely — established plants rely on rainfall; water only in prolonged drought | Mildly toxic to pets |
| Goldtau Hair Grass | Medium indirect light (a couple of metres from a window) | Every 5-10 days; keep consistently moist | Pet-safe |
| Goldtau Tufted Hair Grass | Bright indirect light (just back from a sunny window) | Keep evenly moist, watering deeply 1-2 times weekly when dry | Mildly toxic to pets |
| Gollum Jade | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is fully dry, roughly every 2-3 weeks; less in winter | Toxic to pets |
| Gowen Cypress | Direct sun (at least 4-6 hours) | Infrequently; drought-tolerant once established | Mildly toxic to pets |
| Graceful Cattail | Direct sun (at least 4-6 hours) | Continuously moist to submerged | Pet-safe |
| Graceful Cautleya | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry during active growth, approximately every 7-10 days; minimal in winter dormancy | Mildly toxic to pets |
| Gracillimus Maiden Grass | Direct sun (at least 4-6 hours) | Weekly in year one, then mainly during extended dry spells | Mildly toxic to pets |
| Grand Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; rainfall-dependent once mature | Pet-safe |
| Grape-leaved Anemone 'Robustissima' | Bright indirect light (just back from a sunny window) | When the top 4-5 cm of soil is dry, roughly every 7-14 days | Toxic to pets |
| Grapeleaf Abutilon | Direct sun (at least 4-6 hours) | Moderate; established plants are fairly drought-tolerant | Mildly toxic to pets |
| Graptopetalum rusbyi | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | Pet-safe |
| Graptosedum 'California Sunset' | Direct sun (at least 4-6 hours) | Every 1-2 weeks in active growth; far less in winter | Pet-safe |
| Graptoveria 'Acaulis' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 1-2 weeks in growth | Pet-safe |
| Graptoveria 'Fred Ives' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer | Pet-safe |
| Grass-leaf Disa | Bright indirect light (just back from a sunny window) | Keep consistently moist year-round, roughly every 2-3 days in summer | Pet-safe |
| Grass-Leaved Edraianthus | Direct sun (at least 4-6 hours) | Low — allow soil to partially dry between waterings | Mildly toxic to pets |
| Grasshopper Lycaste | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; near-dry rest in winter | Pet-safe |
| Grassy Arrowhead | Direct sun (at least 4-6 hours) | Permanently aquatic; grow in standing water 5–30 cm (2–12 in) deep | Pet-safe |
| Gray Birch | Direct sun (at least 4-6 hours) | Moderate; tolerates drier conditions than most birches once established | Pet-safe |
| Gray Goldenrod | Direct sun (at least 4-6 hours) | Very drought-tolerant; supplemental water rarely needed | Pet-safe |
| Gray Organ Pipe | Direct sun (at least 4-6 hours) | When the top half of soil is dry, roughly every 10-14 days in summer; very infrequently in winter | Pet-safe |
| Gray's sedge | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water every 2–4 days in dry weather | Pet-safe |
| Grayleaf Cranesbill | Direct sun (at least 4-6 hours) | Every 7–10 days when dry; very sparingly in winter | Pet-safe |
| Grayswood Pink Rock Rose | Direct sun (at least 4-6 hours) | Minimal once established — established plants are drought-tolerant and need watering only during prolonged summer dry spells. | Mildly toxic to pets |
| Great Expectations Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Great Masterwort | Medium indirect light (a couple of metres from a window) | Regularly — keep soil evenly moist throughout the growing season | Mildly toxic to pets |
| Great Mullein | Direct sun (at least 4-6 hours) | Low — once established, rainfall is usually sufficient | Mildly toxic to pets |
| Great Pond Sedge | Direct sun (at least 4-6 hours) | Permanently wet; grows in standing water or waterlogged soil | Pet-safe |
| Great White Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist in spring; reduce after summer dormancy | Mildly toxic to pets |
| Greater Coreopsis | Bright indirect light (just back from a sunny window) | Low to moderate; drought-tolerant once established | Pet-safe |
| Greater Duckweed | Direct sun (at least 4-6 hours) | Permanently floating on water surface | Pet-safe |
| Greater Fringed Gentian | Bright indirect light (just back from a sunny window) | Regular — consistently moist | Pet-safe |
| Greater Knapweed | Direct sun (at least 4-6 hours) | Rarely needed once established; water new plants occasionally through their first summer | Pet-safe |
| Greater Pyramidal Saxifrage | Direct sun (at least 4-6 hours) | Every 10–14 days during the growing season; very sparingly in winter | Pet-safe |
| Greater Quaking Grass | Direct sun (at least 4-6 hours) | Water seedlings until established, then only during prolonged drought, roughly every 10-14 days | Mildly toxic to pets |
| Greater Sea Spurrey | Direct sun (at least 4-6 hours) | Minimal supplemental watering; relies on coastal rainfall and tidal humidity | Mildly toxic to pets |
| Greater Spearwort | Direct sun (at least 4-6 hours) | Shallow to moderate water depth: 10–45 cm | Toxic to pets |
| Greater Stitchwort | Medium indirect light (a couple of metres from a window) | Moderate; keep soil evenly moist during spring and summer | Mildly toxic to pets |
| Greek Cyclamen | Bright indirect light (just back from a sunny window) | Dry in summer dormancy; moderate during autumn and winter growth | Toxic to pets |
| Greek Fir | Direct sun (at least 4-6 hours) | Every 2–3 weeks during establishment; rarely needed once mature | Pet-safe |
| Greek Jancaea | Medium indirect light (a couple of metres from a window) | Little and often to keep root zone moist; almost dry during winter dormancy | Pet-safe |
| Greek yarrow | Direct sun (at least 4-6 hours) | Every 10–14 days during establishment; minimal once mature | Mildly toxic to pets |
| Green Arrow Arum | Direct sun (at least 4-6 hours) | Permanent standing water or consistently saturated soil; never allow to dry out | Toxic to pets |
| Green Ash | Direct sun (at least 4-6 hours) | Weekly when establishing; drought-tolerant once mature | Pet-safe |
| Green Cliff Brake Fern | Medium indirect light (a couple of metres from a window) | When the top half of the soil is dry, roughly every 7-10 days in summer and every 14 days in winter | Pet-safe |
| Green Dragon | Medium indirect light (a couple of metres from a window) | Regularly during spring and summer growing season | Toxic to pets |
| Green Gem Boxwood | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Green Ixia | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days during active growth | Mildly toxic to pets |
| Green Milkweed | Direct sun (at least 4-6 hours) | Low to moderate; every 1–2 weeks once established | Toxic to pets |
| Green Moor Grass | Medium indirect light (a couple of metres from a window) | Every 1–2 weeks during establishment; largely self-sufficient once established | Pet-safe |
| Green Rock Fern | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is completely dry, roughly every 10-14 days | Pet-safe |
| Green Sapote | Direct sun (at least 4-6 hours) | Every 7–10 days; allow partial drying between irrigations | Mildly toxic to pets |
| Green Spleenwort | Medium indirect light (a couple of metres from a window) | When the top centimetre of soil dries out | Pet-safe |
| Green Velvet Boxwood | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Green-Flowered Galtonia | Direct sun (at least 4-6 hours) | Regular from spring through late summer; reduce in autumn | Pet-safe |
| Green-flowered Pitaya | Direct sun (at least 4-6 hours) | Every 2–4 weeks in spring and summer; essentially dry in winter | Mildly toxic to pets |
| Green-tip Forest Lily | Bright indirect light (just back from a sunny window) | Water moderately in spring and summer; reduce to barely moist in autumn and winter. | Toxic to pets |
| Green-winged Orchid | Direct sun (at least 4-6 hours) | Rain-fed; moist spring, dry summer dormancy | Mildly toxic to pets |
| Greene's Liveforever | Bright indirect light (just back from a sunny window) | Every 2–3 weeks during active growth (autumn–spring); very little to none in summer | Pet-safe |
| Greenish Air Plant | Bright indirect light (just back from a sunny window) | 2–3 times per week (misting) or weekly soak | Pet-safe |
| Greenspire Linden | Direct sun (at least 4-6 hours) | Moderate; deep watering during establishment and drought | Pet-safe |
| Greenstem Forsythia | Direct sun (at least 4-6 hours) | Weekly while establishing, then drought-tolerant | Pet-safe |
| Grefsheim Spirea | Direct sun (at least 4-6 hours) | Weekly until established; reduce to occasional watering in drought | Pet-safe |
| Greig's Tulip | Direct sun (at least 4-6 hours) | Rainfall-dependent during growth; needs dry summer dormancy | Toxic to pets |
| Grey Club-rush | Direct sun (at least 4-6 hours) | Shallow to moderately deep aquatic; 10–60 cm over the crown | Pet-safe |
| Grey Sage | Direct sun (at least 4-6 hours) | Every 10-14 days; drought-tolerant once established | Pet-safe |
| Grey Speedwell | Direct sun (at least 4-6 hours) | Every 14–21 days during growing season; barely any in winter | Pet-safe |
| Grigua Cycad | Direct sun (at least 4-6 hours) | Every 21–30 days; very drought-tolerant | Toxic to pets |
| Grinning Argyroderma | Direct sun (at least 4-6 hours) | Every 3–4 weeks in autumn (main growing season); once or twice in spring; completely withheld mid-summer | Pet-safe |
| Guadua Bamboo | Direct sun (at least 4-6 hours) | Frequently during establishment; moderate once mature | Pet-safe |
| Guatemalan Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week, or soak for 20–30 minutes once a week | Pet-safe |
| Guatemalan Blue Sage | Medium indirect light (a couple of metres from a window) | Every 5-7 days during the growing season | Pet-safe |
| Guatemalan Ponytail Palm | Bright indirect light (just back from a sunny window) | Every 14–21 days in summer; every 28–42 days in winter | Mildly toxic to pets |
| Guernsey Lily | Direct sun (at least 4-6 hours) | Completely dry in summer; begin watering in late summer as flower spikes emerge; water regularly until foliage dies back in late spring | Toxic to pets |
| Gumbo Limbo | Direct sun (at least 4-6 hours) | Weekly when newly planted; once established, drought-tolerant and needs watering only during prolonged dry spells | Pet-safe |
| Gunnera manicata | Bright indirect light (just back from a sunny window) | Keep permanently wet; never let the rootzone dry | Mildly toxic to pets |
| Gurken's Orthophytum | Direct sun (at least 4-6 hours) | Allow to dry between waterings — roughly every 7–10 days | Pet-safe |
| Gymnocarpium dryopteris 'Plumosum' | Low light (north window or shaded room) | Keep the soil consistently moist, watering when the top 1-2 cm dries, roughly every 4-6 days | Mildly toxic to pets |
| Gypsicola Butterwort | Bright indirect light (just back from a sunny window) | Keep damp via a shallow tray during summer growth; water sparingly once the succulent winter rosette forms | Mildly toxic to pets |
| Gypsum Butterwort | Bright indirect light (just back from a sunny window) | Tray-water sparingly in summer; near-dry in winter dormancy | Mildly toxic to pets |
| Haage's Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; every 4–6 weeks in winter | Mildly toxic to pets |
| Hackberry Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil dries, regularly in summer | Mildly toxic to pets |
| Hairy Aichryson | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; once monthly or less in winter | Mildly toxic to pets |
| Hairy Alpine Primrose | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth; minimal in summer and winter | Mildly toxic to pets |
| Hairy Coreopsis | Direct sun (at least 4-6 hours) | Low to moderate; water during establishment, then as needed during drought | Pet-safe |
| Hairy Gibbaeum | Bright indirect light (just back from a sunny window) | Every 3–4 weeks in winter and spring (active season); dry in summer | Pet-safe |
| Hairy Hydrangea | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil feels dry, roughly every 5-7 days in summer | Toxic to pets |
| Hairy Lip Fern | Bright indirect light (just back from a sunny window) | every 2-3 weeks (drought-tolerant once established) | Mildly toxic to pets |
| Hairy Primrose | Bright indirect light (just back from a sunny window) | Regularly during active growth (spring–autumn); sparingly in winter | Toxic to pets |
| Hairy Rattleweed | Direct sun (at least 4-6 hours) | Low; allow soil to dry between waterings | Toxic to pets |
| Hairy Rock-cress | Direct sun (at least 4-6 hours) | Low; water only during prolonged drought | Mildly toxic to pets |
| Hairy Sage | Direct sun (at least 4-6 hours) | Moderate; water when the top 3–5 cm of soil is dry | Mildly toxic to pets |
| Hairy Solomon's Seal | Medium indirect light (a couple of metres from a window) | Regular; keep evenly moist | Mildly toxic to pets |
| Hairy St John's-wort | Medium indirect light (a couple of metres from a window) | Moderate — water when the top 2–3 cm of soil is dry | Toxic to pets |
| Hairy Stonecrop | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season; minimal in winter | Pet-safe |
| Hairy Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep medium consistently moist; use a shallow tray with no more than 1 cm of water | Pet-safe |
| Hairy Sun Rose | Direct sun (at least 4-6 hours) | Very low — once every 3–4 weeks in the growing season once established | Mildly toxic to pets |
| Hairy Water Clover | Medium indirect light (a couple of metres from a window) | Permanently in waterlogged substrate or submerged | Mildly toxic to pets |
| Hairy-fruited Draba | Direct sun (at least 4-6 hours) | Every 10–14 days during growth; very little in winter | Pet-safe |
| Hairy-leaf Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the active (cool) season; minimal or none in summer | Toxic to pets |
| Hairy-tongued Restrepia | Medium indirect light (a couple of metres from a window) | Every 2–4 days; medium stays lightly moist | Pet-safe |
| Hakonechloa All Gold | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Halesia carolina | Bright indirect light (just back from a sunny window) | Weekly while establishing; regular watering in dry spells | Pet-safe |
| Halesia monticola | Bright indirect light (just back from a sunny window) | Weekly while establishing; regular watering in dry spells | Pet-safe |
| Half-hidden Yam | Bright indirect light (just back from a sunny window) | Every 2–3 weeks during the growing season; very sparingly or not at all during dormancy | Mildly toxic to pets |
| Half-Stained Sage | Direct sun (at least 4-6 hours) | Every 7–10 days in active growth; reduce in winter | Mildly toxic to pets |
| Hall Totara | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days for young plants | Toxic to pets |
| Hall's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during active growth (autumn to early spring); none in summer dormancy | Pet-safe |
| Hall's Living Stones | Direct sun (at least 4-6 hours) | Seasonally — water in autumn (September–November) only; completely dry in winter and summer | Pet-safe |
| Hameln Dwarf Fountain Grass | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, about weekly while establishing; drought-tolerant once settled | Pet-safe |
| Hameln Fountain Grass | Direct sun (at least 4-6 hours) | Weekly for the first season; every 2 weeks once established | Pet-safe |
| Hamilton's Sundew | Bright indirect light (just back from a sunny window) | Keep tray with 1–2 cm of water at all times | Pet-safe |
| Hand-Bearing Oncidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 10–14 days in winter | Pet-safe |
| Hansa Rose | Direct sun (at least 4-6 hours) | Water weekly while establishing; drought-tolerant once settled | Pet-safe |
| Happy Wanderer | Bright indirect light (just back from a sunny window) | Low to moderate; drought tolerant once established | Mildly toxic to pets |
| Hard Fern | Medium indirect light (a couple of metres from a window) | 2-3 times per week in growing season; reduce slightly in winter | Pet-safe |
| Hard Rush | Direct sun (at least 4-6 hours) | Consistently moist to saturated soil; tolerates standing water to 7 cm (3 in) deep | Pet-safe |
| Hardy Chinese Windmill Palm | Direct sun (at least 4-6 hours) | Weekly while establishing; established garden plants need little extra water | Pet-safe |
| Hardy Cyclamen | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry during active growth (autumn-spring); withhold water during summer dormancy | Toxic to pets |
| Hardy Geranium 'Rozanne' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; about weekly, more in heat or containers | Mildly toxic to pets |
| Hardy Ice Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during active growth; keep dry in winter | Mildly toxic to pets |
| Hardy Ice Plant | Direct sun (at least 4-6 hours) | When the top 3–4 cm of soil is dry, roughly every 7–14 days in summer and very sparingly in winter | Mildly toxic to pets |
| Hare's Tail Grass | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-14 days | Pet-safe |
| Harlequin Flower | Direct sun (at least 4-6 hours) | Water freely when in active growth; stop completely once foliage yellows | Mildly toxic to pets |
| Harlow Carr Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; more in heat or pots | Pet-safe |
| Harris's Air Plant | Bright indirect light (just back from a sunny window) | Mist thoroughly 2–3 times per week or soak for 20–30 minutes once a week. | Mildly toxic to pets |
| Hart's Tongue Fern | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Hartford Climbing Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in active growth | Pet-safe |
| Hasse's Liveforever | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (autumn–spring); virtually none in summer | Pet-safe |
| Hatchet Cactus | Direct sun (at least 4-6 hours) | When the potting mix is completely dry, roughly every 14-21 days in summer; very sparingly in winter (once every 4-6 weeks) | Pet-safe |
| Hatfieldii Yew | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Hatschbach's Fuchsia | Bright indirect light (just back from a sunny window) | Water freely in growth; keep just moist in winter | Pet-safe |
| Haussknecht's Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season (spring–summer); every 4–6 weeks or rainfall-only in winter | Pet-safe |
| Haworth's Lampranthus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; sparingly in summer dormancy | Mildly toxic to pets |
| Hay-Scented Fern | Medium indirect light (a couple of metres from a window) | Keep evenly moist while establishing; water when the top 2-3 cm of soil is dry, roughly weekly | Mildly toxic to pets |
| Haygarth's Cape Primrose | Bright indirect light (just back from a sunny window) | Every 7-10 days in growth; every 3-4 weeks in winter | Pet-safe |
| Hayne's Matucana | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, every 7-14 days in summer | Pet-safe |
| Hazel Smith Sequoia | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in the growing season | Mildly toxic to pets |
| Heart-leaf Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 1–2 days; mounted plants may need daily misting | Pet-safe |
| Heart-leaved Blechnum | Medium indirect light (a couple of metres from a window) | Twice a week in summer, once a week in cooler months | Pet-safe |
| Heartleaf Foamflower | Medium indirect light (a couple of metres from a window) | Regular; keep consistently moist | Pet-safe |
| Heath Speedwell | Bright indirect light (just back from a sunny window) | Low to moderate — allow soil to partially dry between waterings | Pet-safe |
| Heath Spotted Orchid | Bright indirect light (just back from a sunny window) | Consistent moisture from rainfall | Mildly toxic to pets |
| Heath-leaved Sage | Direct sun (at least 4-6 hours) | Low; water deeply every 2–3 weeks when established | Mildly toxic to pets |
| Heavy Metal Switch Grass | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water deeply every 1-2 weeks while young | Mildly toxic to pets |
| Hechtia texensis | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Mildly toxic to pets |
| Hedera canariensis | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Hedera colchica | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in growth | Toxic to pets |
| Hedera colchica 'Dentata Variegata' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in growth | Toxic to pets |
| Hedera helix 'Glacier' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Hedera helix 'Goldheart' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Hedera helix 'Ivalace' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Hedge Bamboo | Bright indirect light (just back from a sunny window) | 2-3 times per week; daily in summer heat or in containers | Pet-safe |
| Hedge Bedstraw | Bright indirect light (just back from a sunny window) | Low to moderate — rainfall usually sufficient | Mildly toxic to pets |
| Hedge bindweed | Direct sun (at least 4-6 hours) | Tolerates drought once established; water young plants weekly until roots are established | Mildly toxic to pets |
| Hedge Woundwort | Medium indirect light (a couple of metres from a window) | Regularly during active growth; reduce in winter | Mildly toxic to pets |
| Hedgerow Cranesbill | Bright indirect light (just back from a sunny window) | Low to moderate; water only to establish, then drought-tolerant | Pet-safe |
| Heldreich's Sage | Direct sun (at least 4-6 hours) | Occasional; drought-tolerant once established | Pet-safe |
| Helenium 'Chipperfield Orange' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days during dry periods | Toxic to pets |
| Helenium 'Coppelia' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in dry summer weather | Toxic to pets |
| Helenium 'Floretan' | Direct sun (at least 4-6 hours) | Every 5-7 days; maintain consistent soil moisture through summer | Toxic to pets |
| Helenium 'Helbro' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water every 3-5 days during dry summer spells | Toxic to pets |
| Helenium 'Pumilum Magnificum' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in dry weather | Toxic to pets |
| Helenium 'Riverton Beauty' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in warm, dry weather | Toxic to pets |
| Helenium 'Rotgold' | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil is dry, roughly every 4-7 days in summer | Mildly toxic to pets |
| Helenium 'Rubinzwerg' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days during dry summer spells | Toxic to pets |
| Helenium 'Sahin's Early Flowerer' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days during dry summer spells | Toxic to pets |
| Helenium 'Short and Sassy' | Direct sun (at least 4-6 hours) | Every 5-7 days; do not allow soil to dry out completely during summer | Toxic to pets |
| Helenium 'Waldtraut' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water every 3-5 days during dry spells | Toxic to pets |
| Helenium 'Wyndley' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water every 3-5 days during dry spells | Toxic to pets |
| Helenium autumnale 'Pumilum Magnificum' | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil is dry, roughly every 4-7 days in summer | Mildly toxic to pets |
| Heliamphora ionasi | Bright indirect light (just back from a sunny window) | Keep permanently moist to wet; never allow the medium to dry | Mildly toxic to pets |
| Heliamphora tatei | Bright indirect light (just back from a sunny window) | Keep permanently moist to wet; do not let the medium dry | Mildly toxic to pets |
| Helianthus 'Lemon Queen' | Direct sun (at least 4-6 hours) | Water when the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| Helianthus × multiflorus 'Loddon Gold' | Direct sun (at least 4-6 hours) | About once or twice a week, keeping soil moist in summer | Pet-safe |
| Helianthus decapetalus 'Flore Pleno' | Direct sun (at least 4-6 hours) | Water when the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| Helianthus salicifolius | Direct sun (at least 4-6 hours) | Water when the top 3-4 cm of soil is dry, roughly every 7-10 days; drought-tolerant once established | Pet-safe |
| Hellebore | Medium indirect light (a couple of metres from a window) | Weekly watering until established | Toxic to pets |
| Hellebore 'Penny's Pink' | Medium indirect light (a couple of metres from a window) | Keep evenly moist during establishment and dry spells; established clumps are moderately drought-tolerant | Toxic to pets |
| Helleborus × hybridus | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry; roughly weekly in the first year, then only in dry spells once established | Toxic to pets |
| Helleborus foetidus | Medium indirect light (a couple of metres from a window) | When the top few centimetres of soil dry out; weekly while establishing, then rarely once settled | Toxic to pets |
| Helleborus orientalis 'Ivory Prince' | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry; weekly while establishing, then during dry spells | Toxic to pets |
| Helleri Holly | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 7-14 days during dry weather | Toxic to pets |
| Helmut's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during active autumn-to-spring growth only; strictly none in summer | Pet-safe |
| Hemiboea subcapitata | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Mildly toxic to pets |
| Hemlock Water Dropwort | Direct sun (at least 4-6 hours) | Constantly wet; wetland marginal or in-water species | Toxic to pets |
| Hemlock Water Parsnip | Direct sun (at least 4-6 hours) | Continuously — must have saturated or inundated soil | Toxic to pets |
| Henry's honeysuckle | Medium indirect light (a couple of metres from a window) | Weekly during dry periods; established plants are relatively drought-tolerant | Mildly toxic to pets |
| Henry's Lily | Medium indirect light (a couple of metres from a window) | When top 3–4 cm of soil feels dry | Toxic to pets |
| Herald Trumpet Vine | Direct sun (at least 4-6 hours) | Water every 5-7 days in the growing season, ensuring the top 3-5 cm is slightly dry before watering; reduce significantly in winter to every 2-4 weeks | Mildly toxic to pets |
| Herald's Trumpet | Direct sun (at least 4-6 hours) | Every 5-7 days in growth, every 14 days in winter | Toxic to pets |
| Herb Robert | Medium indirect light (a couple of metres from a window) | Low to moderate; water only during prolonged dry spells | Pet-safe |
| Heritage River Birch | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week in the first 2 years; established trees prefer consistently moist soil | Pet-safe |
| Herradura Masdevallia | Medium indirect light (a couple of metres from a window) | 3–5 times per week | Pet-safe |
| Herre's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during autumn-to-spring active period; none in summer | Pet-safe |
| Herrenhausen Oregano | Direct sun (at least 4-6 hours) | Every 10–14 days when established; more frequently for young plants | Pet-safe |
| Herrenhausen Shield Fern | Low light (north window or shaded room) | Every 3–5 days; keep moist but well-drained | Pet-safe |
| Heterodox Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep substrate evenly moist at all times | Mildly toxic to pets |
| Heterodoxa Sun Pitcher | Bright indirect light (just back from a sunny window) | Water every 3-5 days, maintaining a consistently moist but not waterlogged substrate; keep pitchers partially filled with distilled or rainwater | Pet-safe |
| Heuchera 'Amber Waves' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-10 days in the growing season | Mildly toxic to pets |
| Heuchera 'Berry Smoothie' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days during active growth | Mildly toxic to pets |
| Heuchera 'Carnival Rose Granita' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Heuchera 'Citronelle' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Mildly toxic to pets |
| Heuchera 'Dolce Blackcurrant' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-9 days in the growing season | Mildly toxic to pets |
| Heuchera 'Dolce Cinnamon Curls' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days during active growth | Mildly toxic to pets |
| Heuchera 'Fire Alarm' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days in the growing season | Mildly toxic to pets |
| Heuchera 'Galaxy' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-9 days during growth | Mildly toxic to pets |
| Heuchera 'Georgia Peach' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days during active growth | Mildly toxic to pets |
| Heuchera 'Grape Expectations' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-9 days during the growing season | Mildly toxic to pets |
| Heuchera 'Green Spice' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Hollywood' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Key Lime Pie' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Lime Marmalade' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Mildly toxic to pets |
| Heuchera 'Mahogany' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Marmalade' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Heuchera 'Midnight Rose' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Miracle' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Mocha' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Northern Exposure Amber' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Peach Flambe' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Pewter Moon' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Plum Pudding' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-9 days in summer | Mildly toxic to pets |
| Heuchera 'Purple Petticoats' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Quicksilver' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Raspberry Ice' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Rave On' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Heuchera 'Saturn' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Heuchera 'Silver Scrolls' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Heuchera 'Sparkling Burgundy' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Heuchera 'Sugar Berry' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Heuchera 'Tiramisu' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days during growth | Mildly toxic to pets |
| Heuchera 'Venus' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Heuchera villosa 'Autumn Bride' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| Heucherella 'Tapestry' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about every 5-7 days in summer | Pet-safe |
| Heucherella Brass Lantern | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Pet-safe |
| Heucherella Stoplight | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply once or twice a week in dry spells | Pet-safe |
| Heucherella Sunrise Falls | Medium indirect light (a couple of metres from a window) | Keep evenly moist; in containers and baskets water more often, even daily in summer heat | Pet-safe |
| Heucherella Sweet Tea | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply once or twice a week in dry weather | Pet-safe |
| Hibiscus syriacus 'Aphrodite' | Direct sun (at least 4-6 hours) | Weekly while establishing; every 10-14 days once mature unless rainfall is sparse | Pet-safe |
| Hibiscus syriacus 'Blue Bird' | Direct sun (at least 4-6 hours) | Water weekly during the first two seasons and in summer droughts; established plants are moderately drought-tolerant | Pet-safe |
| Hibiscus syriacus 'Helene' | Direct sun (at least 4-6 hours) | Water weekly while establishing and during summer drought; moderately drought-tolerant once mature | Pet-safe |
| Hibiscus syriacus 'Minerva' | Direct sun (at least 4-6 hours) | Water weekly during establishment and summer drought; moderately drought-tolerant once established | Pet-safe |
| Hicksii Yew | Medium indirect light (a couple of metres from a window) | Every 7-10 days while establishing, then as needed | Toxic to pets |
| Hilde's Air Plant | Bright indirect light (just back from a sunny window) | Daily misting in warm weather; 2–3 times per week in winter. | Mildly toxic to pets |
| Himalayan Cotoneaster | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry; established plants are drought-tolerant once settled | Toxic to pets |
| Himalayan Cypress | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in dry spells | Mildly toxic to pets |
| Himalayan Inula | Bright indirect light (just back from a sunny window) | 2-3 times per week; maintain consistent moisture | Pet-safe |
| Himalayan pieris | Bright indirect light (just back from a sunny window) | Regular; keep consistently moist | Toxic to pets |
| Himalayan Pieris Wakehurst | Bright indirect light (just back from a sunny window) | Water every 7–10 days; do not allow to dry out, particularly during spring growth flush | Toxic to pets |
| Hinds' Torchwood | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; very rarely in winter dormancy | Mildly toxic to pets |
| Hinoki Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days while establishing, then when the top few cm of soil dry | Mildly toxic to pets |
| Hinoki Cypress Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil begins to dry, often daily in summer | Mildly toxic to pets |
| Hirsute Slipper Orchid | Medium indirect light (a couple of metres from a window) | Every 4–5 days in growth; occasional misting only during 30–40 day winter rest | Pet-safe |
| Hirta Toad Lily | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water when the surface begins to dry, typically once or twice a week in summer | Mildly toxic to pets |
| Hirtz's Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting; never allow roots to fully dry | Pet-safe |
| Histrioides Iris | Direct sun (at least 4-6 hours) | Moderate in late winter and spring; dry in summer | Toxic to pets |
| Hoary Plantain | Direct sun (at least 4-6 hours) | Rarely; established plants are drought-tolerant | Pet-safe |
| Hoary Stock | Direct sun (at least 4-6 hours) | Weekly, allowing soil to dry slightly between waterings | Pet-safe |
| Hobbit Jade | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is fully dry, about every 2-3 weeks; less in winter | Toxic to pets |
| Hogweed | Bright indirect light (just back from a sunny window) | Regular during establishment; drought-tolerant once established | Mildly toxic to pets |
| Holger Juniper | Direct sun (at least 4-6 hours) | Water regularly the first season; afterward only in extended drought | Toxic to pets |
| Hollow Joe Pye Weed | Direct sun (at least 4-6 hours) | Keep soil reliably moist; water weekly or more during dry weather | Pet-safe |
| Hollow-Rooted Fumewort | Medium indirect light (a couple of metres from a window) | Rainfall-dependent during spring growth; completely dry in summer dormancy | Toxic to pets |
| Holmgren's Dioon | Direct sun (at least 4-6 hours) | Every 3–5 weeks in the growing season; monthly or less in winter | Toxic to pets |
| Holmstrup Arborvitae | Direct sun (at least 4-6 hours) | Two to three times weekly when young; weekly once established | Mildly toxic to pets |
| Honesty | Medium indirect light (a couple of metres from a window) | Twice weekly in dry spells; keep soil consistently moist | Mildly toxic to pets |
| Honey Garlic | Bright indirect light (just back from a sunny window) | Low; rainfall usually sufficient once established in the UK | Toxic to pets |
| Honeysuckle Fuchsia | Bright indirect light (just back from a sunny window) | Daily in active growth; less in winter | Pet-safe |
| Hooded Dendrobium | Bright indirect light (just back from a sunny window) | Abundant in summer growth; nearly withheld over the deciduous winter rest | Pet-safe |
| Hooded Maxillaria | Medium indirect light (a couple of metres from a window) | Every 5–7 days year-round; slight reduction in winter | Pet-safe |
| Hooded Pitcher Plant | Direct sun (at least 4-6 hours) | Keep the tray method: maintain 1-3 cm of distilled or rainwater in the saucer at all times during the growing season; reduce to just-moist in winter dormancy | Pet-safe |
| Hooded Pleurothallis | Medium indirect light (a couple of metres from a window) | Daily misting or watering; roots must remain evenly moist at all times | Pet-safe |
| Hooded-leaf Pelargonium | Direct sun (at least 4-6 hours) | Water when the top 3–4 cm of compost is dry, approximately every 7–12 days in the growing season; keep barely moist in winter | Toxic to pets |
| Hoogendorn Holly | Direct sun (at least 4-6 hours) | Weekly deep watering when young, then every 7-14 days in dry weather | Toxic to pets |
| Hook Sedge | Direct sun (at least 4-6 hours) | Keep evenly moist; water weekly in dry spells and don't let containers fully dry | Mildly toxic to pets |
| Hooker's Holly Fern | Medium indirect light (a couple of metres from a window) | Every 7–10 days, less in winter | Pet-safe |
| Hooker's Inula | Bright indirect light (just back from a sunny window) | 2 times per week; tolerates periodic damp conditions | Pet-safe |
| Hooker's Orchid Cactus | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, approximately every 7-14 days in spring and summer; reduce to once every 3-4 weeks in autumn and winter | Pet-safe |
| Hoop Petticoat Daffodil | Direct sun (at least 4-6 hours) | Once per week during spring growth; withhold irrigation after foliage yellows | Toxic to pets |
| Hoopsii Blue Spruce | Direct sun (at least 4-6 hours) | Water deeply weekly for the first two to three years, then only in extended dry spells | Mildly toxic to pets |
| Horn-Bearing Coryphantha | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, roughly every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Horned Eriosyce | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once a month or less in winter | Pet-safe |
| Horned violet | Bright indirect light (just back from a sunny window) | Every 5–7 days; keep evenly moist | Pet-safe |
| Horse Crippler Cactus | Direct sun (at least 4-6 hours) | Every 3–4 weeks in spring and summer; dry rest in winter | Mildly toxic to pets |
| Horseshoe Vetch | Direct sun (at least 4-6 hours) | Rarely — established plants are very drought-tolerant | Mildly toxic to pets |
| Horst's Gymnocalycium | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, approximately every 7-10 days in summer; every 3-4 weeks in winter | Pet-safe |
| Horstmann Korean Fir | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hosta | Medium indirect light (a couple of metres from a window) | Keep evenly moist; roughly weekly in the ground, more often in pots or heat | Toxic to pets |
| Hosta 'Blue Angel' | Medium indirect light (a couple of metres from a window) | Every 5-7 days during the growing season, or when the top 3-5 cm of soil is drying | Toxic to pets |
| Hosta 'El Nino' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7 days during the growing season | Toxic to pets |
| Hosta 'Elegans' | Medium indirect light (a couple of metres from a window) | Every 5-7 days during the growing season, or when the top 3-5 cm of soil is drying | Toxic to pets |
| Hosta 'Empress Wu' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Hosta 'Fire Island' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Hosta 'Fortunei Aureomarginata' | Medium indirect light (a couple of metres from a window) | Every 5-7 days during the growing season, or when the top 3-5 cm of soil is drying | Toxic to pets |
| Hosta 'Frances Williams' | Medium indirect light (a couple of metres from a window) | Every 5-7 days in the growing season, or when the top 3-5 cm of soil is drying out | Toxic to pets |
| Hosta 'Golden Tiara' | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Great Expectations' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Hosta 'Guacamole' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Halcyon' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Invincible' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Island Charm' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Krossa Regal' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7 days during the growing season | Toxic to pets |
| Hosta 'Lancifolia' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in summer | Toxic to pets |
| Hosta 'Midnight Rider' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in summer | Toxic to pets |
| Hosta 'Night Before Christmas' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'On Stage' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Patriot' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Hosta 'Patriot' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days through the growing season | Toxic to pets |
| Hosta 'Paul Revere' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Hosta 'Pineapple Upside Down Cake' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Regal Splendor' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Remember Me' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Hosta 'Revolution' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Hosta 'Royal Standard' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Sagae' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Hosta 'Shade Fanfare' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Something Different' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in summer | Toxic to pets |
| Hosta 'Stained Glass' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Hosta 'Sum and Substance' | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, about every 5-7 days; more in heat | Toxic to pets |
| Hosta 'Sum and Substance' | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Touch of Class' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7 days during the growing season | Toxic to pets |
| Hosta 'Twilight' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Undulata Albomarginata' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Ventricosa' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Hosta 'Wheel of Fortune' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in summer | Toxic to pets |
| Hosta 'Wide Brim' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Hound's-tongue | Direct sun (at least 4-6 hours) | Rarely, once established | Toxic to pets |
| Houseleek Cliff Stonecrop | Direct sun (at least 4-6 hours) | Every 14–21 days in the growing season; very sparingly in winter | Pet-safe |
| Houseleek Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; very sparingly in winter | Pet-safe |
| Hoya polyneura (Fishtail Hoya) | Bright indirect light (just back from a sunny window) | Roughly weekly in spring and summer; every 2-3 weeks in winter | Pet-safe |
| Humboldt's Bladderwort | Bright indirect light (just back from a sunny window) | Keep bromeliad tank or equivalent reservoir filled with 2–5 cm of pure water at all times; change every 1–2 weeks | Pet-safe |
| Humboldt's Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 5-6 weeks in winter | Pet-safe |
| Hume Roscoea | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry during active growth, approximately every 10-14 days; nearly none in winter dormancy | Mildly toxic to pets |
| Humulus lupulus 'Aureus' | Direct sun (at least 4-6 hours) | Keep soil reliably moist in the growing season, about every 3-5 days in summer | Toxic to pets |
| Hunchback Gymnocalycium | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in summer; every 3-4 weeks in winter | Pet-safe |
| Hungarian Lilac | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hungarian Oak | Direct sun (at least 4-6 hours) | Establish with regular watering in year 1–2; highly drought-tolerant once established | Mildly toxic to pets |
| Huron Sunrise Miscanthus | Direct sun (at least 4-6 hours) | Weekly in the establishment year; thereafter only during prolonged drought | Mildly toxic to pets |
| Hyacinth | Bright indirect light (just back from a sunny window) | Weekly watering during growth | Toxic to pets |
| Hyacinthus orientalis 'Carnegie' | Direct sun (at least 4-6 hours) | Moist through growth and flowering; reduce after foliage dies back | Toxic to pets |
| Hyacinthus orientalis 'City of Haarlem' | Direct sun (at least 4-6 hours) | Moist during growth and flowering; reduce after foliage dies back | Toxic to pets |
| Hyacinthus orientalis 'Delft Blue' | Direct sun (at least 4-6 hours) | Keep soil moist during growth and flowering; reduce sharply after foliage dies back | Toxic to pets |
| Hyacinthus orientalis 'Jan Bos' | Direct sun (at least 4-6 hours) | Moist through growth and flowering; reduce after foliage dies back | Toxic to pets |
| Hyacinthus orientalis 'Woodstock' | Direct sun (at least 4-6 hours) | Moist during growth and flowering; much drier after dormancy sets in | Toxic to pets |
| Hybrid trumpet vine | Direct sun (at least 4-6 hours) | Weekly during establishment; established plants are drought-tolerant | Mildly toxic to pets |
| Hydrangea 'Annabelle' | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water deeply 2-3 times weekly in summer, more in heat or drought | Toxic to pets |
| Hydrangea 'Annabelle' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days; more frequently in hot weather | Mildly toxic to pets |
| Hydrangea 'Blushing Bride' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil feels dry, roughly every 3-5 days in summer heat | Mildly toxic to pets |
| Hydrangea 'Bobo' | Bright indirect light (just back from a sunny window) | When the top 3 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hydrangea 'Endless Summer' | Bright indirect light (just back from a sunny window) | Keep consistently moist; water deeply 2-3 times weekly in heat | Toxic to pets |
| Hydrangea 'Endless Summer' | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water deeply 2-3 times weekly in summer heat, more for containers | Toxic to pets |
| Hydrangea 'Incrediball' | Bright indirect light (just back from a sunny window) | When the top 5 cm of soil is dry, about 2-3 times per week in summer | Toxic to pets |
| Hydrangea 'Let's Dance Rhythmic Blue' | Bright indirect light (just back from a sunny window) | When the top 3 cm of soil is dry, roughly every 5-7 days during the growing season | Mildly toxic to pets |
| Hydrangea 'Limelight' | Direct sun (at least 4-6 hours) | Keep soil moist while establishing; water deeply once or twice weekly in summer, less once established | Toxic to pets |
| Hydrangea 'Limelight' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hydrangea 'Little Lime' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, about 1-2 times per week | Toxic to pets |
| Hydrangea 'Nikko Blue' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 5-7 days during the growing season | Mildly toxic to pets |
| Hydrangea 'Pee Gee' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Hydrangea 'PeeWee' | Bright indirect light (just back from a sunny window) | When the top 5 cm of soil is dry, about once per week | Toxic to pets |
| Hydrangea 'Pinky Winky' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, about 1-2 times per week | Toxic to pets |
| Hydrangea 'Quick Fire' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Hydrangea 'Snowflake' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hydrangea 'Strawberry Sundae' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Hydrangea 'Tardiva' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Hydrangea 'Vanilla Strawberry' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly 1-2 times per week | Toxic to pets |
| Hydrangea aspera 'Villosa' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply every 5-7 days in dry summer spells | Toxic to pets |
| Hydrocharis morsus-ranae | Direct sun (at least 4-6 hours) | Free-floating; keep on the surface of still or slow water | Mildly toxic to pets |
| Hylotelephium 'Autumn Joy' | Direct sun (at least 4-6 hours) | Roughly every 10-14 days in its first season; established plants rarely need watering | Pet-safe |
| Hylotelephium 'Purple Emperor' | Direct sun (at least 4-6 hours) | Every 10-14 days when young; established plants need little to no watering | Pet-safe |
| Hylotelephium spectabile 'Brilliant' | Direct sun (at least 4-6 hours) | Every 10-14 days while establishing; mature clumps rely on rainfall | Pet-safe |
| Hylotelephium telephium 'Munstead Dark Red' | Direct sun (at least 4-6 hours) | Every 10-14 days while establishing; mature plants are largely self-reliant | Pet-safe |
| Iberian Cranesbill | Bright indirect light (just back from a sunny window) | Weekly in spring and summer; occasional in autumn | Pet-safe |
| Ice Dance Sedge | Medium indirect light (a couple of metres from a window) | Keep moist while establishing; water deeply weekly in dry spells | Mildly toxic to pets |
| Ice Plant | Direct sun (at least 4-6 hours) | Every 10-14 days during establishment; mature clumps rely on rainfall | Pet-safe |
| Idaho fescue | Direct sun (at least 4-6 hours) | Very low; water every 2–3 weeks during the first season; monthly or less once established | Pet-safe |
| Imbricate Sword Fern | Low light (north window or shaded room) | Every 5–7 days in summer, every 10–14 days in winter | Pet-safe |
| Immersed Stelis | Medium indirect light (a couple of metres from a window) | Daily misting for mounted specimens; every 2 days for potted plants | Pet-safe |
| Imperial Air Plant | Bright indirect light (just back from a sunny window) | Mist daily or soak for 20–30 minutes 2–3 times per week in the growing season. | Mildly toxic to pets |
| Imperial Bromeliad | Direct sun (at least 4-6 hours) | Water sparingly; allow potting medium to almost completely dry between waterings | Pet-safe |
| Indian Cucumber Root | Low light (north window or shaded room) | Consistently moist; water whenever the top 2–3 cm of soil begins to dry during the growing season | Mildly toxic to pets |
| Indian Fig Opuntia | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Indian Head Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 7-10 days in spring and summer; every 3-4 weeks in autumn; minimal in winter | Pet-safe |
| Indian Head Notocactus | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in the active growing season; reduce to once every 5-8 weeks in winter | Pet-safe |
| Indian Sinocrassula | Direct sun (at least 4-6 hours) | Every 2–4 weeks in growing season; monthly or less in winter | Mildly toxic to pets |
| Inflated Bladderwort | Direct sun (at least 4-6 hours) | Permanently aquatic in soft, acidic, low-nutrient water; refresh or top up with distilled or rainwater as needed | Pet-safe |
| Inflated Rock Rose | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; weekly in the first season | Mildly toxic to pets |
| Inner-rough Pleurothallis | Medium indirect light (a couple of metres from a window) | When the medium surface is just drying, roughly every 4-6 days | Pet-safe |
| Intense Blue Fescue | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; minimal once established | Mildly toxic to pets |
| Intermediate Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week in summer; 1–2 times per week in winter. | Mildly toxic to pets |
| Intermediate Galangal | Medium indirect light (a couple of metres from a window) | Twice a week in warm months; once a week or less in cooler conditions | Mildly toxic to pets |
| Intermediate Polypody | Medium indirect light (a couple of metres from a window) | Every 7–10 days in active growth (autumn–spring); reduce to every 2–3 weeks in summer | Pet-safe |
| Ionas Sun Pitcher | Bright indirect light (just back from a sunny window) | Water every 3-5 days to keep substrate consistently moist; maintain a partial fill of distilled water in the pitchers at all times | Pet-safe |
| Ionas's Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep soil constantly moist; shallow tray of a few mm of water is acceptable | Mildly toxic to pets |
| Iridescent Bamboo | Direct sun (at least 4-6 hours) | Twice weekly in spring and summer; weekly in autumn; fortnightly in winter | Pet-safe |
| Iris 'Benton Susan' | Direct sun (at least 4-6 hours) | Water at planting and during establishment, then only in prolonged drought; established clumps are drought-tolerant | Toxic to pets |
| Iris 'Black Gamecock' | Direct sun (at least 4-6 hours) | Keep consistently wet; tolerates standing water and never fully dry out | Toxic to pets |
| Iris 'Clarence' | Direct sun (at least 4-6 hours) | Keep moist through spring and late summer to support rebloom; do not waterlog | Toxic to pets |
| Iris 'Immortality' | Direct sun (at least 4-6 hours) | Keep evenly moist through spring and late summer to support rebloom; avoid waterlogging | Toxic to pets |
| Iris 'Jane Phillips' | Direct sun (at least 4-6 hours) | Water deeply during spring growth and after planting; keep drier in summer | Toxic to pets |
| Iris 'Katharine Hodgkin' | Direct sun (at least 4-6 hours) | Water during autumn-to-spring growth; keep dry in summer dormancy | Toxic to pets |
| Iris ensata | Direct sun (at least 4-6 hours) | Keep soil constantly moist in spring and summer; drier in winter | Toxic to pets |
| Iris laevigata | Direct sun (at least 4-6 hours) | Permanently wet; thrives in 0-15 cm of standing water year-round | Toxic to pets |
| Iris laevigata 'Variegata' | Direct sun (at least 4-6 hours) | Permanently wet; thrives in 0-15 cm of standing water year-round | Toxic to pets |
| Iris pseudacorus | Direct sun (at least 4-6 hours) | Permanently wet; thrives in 0-30 cm of standing water | Toxic to pets |
| Iris pseudacorus 'Variegatus' | Direct sun (at least 4-6 hours) | Keep permanently wet; never let the rootzone dry out | Toxic to pets |
| Iris reticulata 'Harmony' | Direct sun (at least 4-6 hours) | Water during autumn-to-spring growth; keep dry in summer dormancy | Toxic to pets |
| Iris versicolor | Direct sun (at least 4-6 hours) | Keep consistently wet to shallowly submerged | Toxic to pets |
| Iris virginica | Direct sun (at least 4-6 hours) | Keep wet to shallowly submerged year-round | Toxic to pets |
| Irish Fleabane | Direct sun (at least 4-6 hours) | Every 7-10 days during the growing season; less in winter | Mildly toxic to pets |
| Iron Butterfly Foamflower | Medium indirect light (a couple of metres from a window) | Once or twice per week during the growing season; water sparingly in winter. | Mildly toxic to pets |
| Iron Butterfly Tiarella | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply once or twice a week when rainfall is short | Mildly toxic to pets |
| Island Liveforever | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in active season (October–April); none to minimal in summer | Pet-safe |
| Italian aster | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; drought-tolerant in summer | Pet-safe |
| Italian Cypress | Direct sun (at least 4-6 hours) | Every 1-2 weeks while establishing, then minimal | Mildly toxic to pets |
| Italian Gladiolus | Direct sun (at least 4-6 hours) | Moderate during growth; dry when dormant | Toxic to pets |
| Italian jasmine | Bright indirect light (just back from a sunny window) | Every 7–14 days; drought-tolerant once established | Mildly toxic to pets |
| Italian Sage Phlomis | Direct sun (at least 4-6 hours) | Low — once every 2–3 weeks once established | Mildly toxic to pets |
| Itea virginica | Bright indirect light (just back from a sunny window) | Keep soil moist; water weekly or more in dry spells, tolerant of wet ground | Mildly toxic to pets |
| Itea virginica 'Henry's Garnet' | Bright indirect light (just back from a sunny window) | Keep soil moist; water weekly or more in dry weather, tolerant of wet ground | Mildly toxic to pets |
| Itea virginica 'Little Henry' | Bright indirect light (just back from a sunny window) | Keep soil moist; water weekly or more in dry spells, tolerant of wet ground | Mildly toxic to pets |
| Ithuriel's Spear | Bright indirect light (just back from a sunny window) | Moderate in spring during active growth; dry summer dormancy required | Mildly toxic to pets |
| Ithuriel's Spear | Direct sun (at least 4-6 hours) | Moderate water during spring growth; dry summer rest required | Mildly toxic to pets |
| Itoh Peony 'Bartzella' | Direct sun (at least 4-6 hours) | Deeply once a week during growth and budding; established plants tolerate short dry spells | Toxic to pets |
| Ivan Cranesbill | Medium indirect light (a couple of metres from a window) | Once or twice a week in dry spells; less in cooler or wetter periods | Pet-safe |
| Ivory Cymbidium | Bright indirect light (just back from a sunny window) | Thorough watering every 5–7 days in active growth; reduce significantly in winter | Pet-safe |
| Ivory Primulina | Medium indirect light (a couple of metres from a window) | Allow the top half of compost to dry before rewatering | Mildly toxic to pets |
| Ivy-Leaved Cyclamen | Medium indirect light (a couple of metres from a window) | Drought-tolerant once established; rely entirely on natural rainfall | Toxic to pets |
| Ivy-leaved Duckweed | Medium indirect light (a couple of metres from a window) | Permanently submerged | Pet-safe |
| Jacqueline Postill Daphne | Bright indirect light (just back from a sunny window) | Roughly every 7-10 days in the growing season, allowing the top 3-5 cm to dry between waterings | Toxic to pets |
| Jalisco Mountain Air Plant | Bright indirect light (just back from a sunny window) | Mist or dunk every 2–3 days in hot weather; once a week in cool, humid conditions. | Mildly toxic to pets |
| Janke's Gesneriad | Medium indirect light (a couple of metres from a window) | Water at the root zone only when the soil approaches dryness, roughly every 10–14 days in the growing season | Mildly toxic to pets |
| Japanese Anemone 'Honorine Jobert' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Japanese Apricot | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil dries, often daily in summer | Toxic to pets |
| Japanese Banana | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 4-6 days in active growth | Pet-safe |
| Japanese barberry | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; drought-tolerant once established | Mildly toxic to pets |
| Japanese Beech | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil begins to dry, often daily in summer | Mildly toxic to pets |
| Japanese Beech Fern | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water when the top 2-3 cm begin to dry, roughly weekly during dry periods | Mildly toxic to pets |
| Japanese Big-Leaf Magnolia | Bright indirect light (just back from a sunny window) | Weekly during dry periods; established trees are moderately drought-tolerant | Pet-safe |
| Japanese Black Pine | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is approaching dry, often daily in summer heat | Mildly toxic to pets |
| Japanese Black Pine 'Kotobuki' | Direct sun (at least 4-6 hours) | When the soil surface is approaching dry, then water thoroughly | Mildly toxic to pets |
| Japanese Black Pine 'Thunderhead' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry; allow slight drying between waterings | Mildly toxic to pets |
| Japanese Blood Grass | Direct sun (at least 4-6 hours) | Keep soil moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Japanese Brake Fern | Medium indirect light (a couple of metres from a window) | Every 4–6 days in the growing season; every 7–10 days in winter | Pet-safe |
| Japanese Camellia | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry; keep evenly moist in late summer | Pet-safe |
| Japanese Camellia 'Nuccio's Pearl' | Bright indirect light (just back from a sunny window) | About weekly, more in heat and during budding; water when the top 3-5 cm of soil is dry | Pet-safe |
| Japanese Cedar 'Cristata' | Direct sun (at least 4-6 hours) | Keep evenly moist; weekly in dry spells, more for young plants | Mildly toxic to pets |
| Japanese Cedar 'Elegans' | Direct sun (at least 4-6 hours) | Keep evenly moist; water weekly in dry spells, more for young plants | Mildly toxic to pets |
| Japanese Cedar 'Globosa Nana' | Direct sun (at least 4-6 hours) | Keep evenly moist; weekly in dry weather, more in containers | Mildly toxic to pets |
| Japanese Cedar 'Spiralis' | Direct sun (at least 4-6 hours) | Keep evenly moist; weekly in dry weather, more for young or potted plants | Mildly toxic to pets |
| Japanese Cedar 'Vilmoriniana' | Direct sun (at least 4-6 hours) | Keep evenly moist; weekly in dry spells, attentive in troughs | Mildly toxic to pets |
| Japanese Cedar Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Japanese Chain Fern | Medium indirect light (a couple of metres from a window) | Every 4–6 days in summer, every 8–12 days in winter | Pet-safe |
| Japanese Cobra Lily | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist during the growing season (spring to early summer); cease watering during summer dormancy | Toxic to pets |
| Japanese Cornel Dogwood | Direct sun (at least 4-6 hours) | Regular watering while establishing; drought-tolerant once mature | Pet-safe |
| Japanese Dunce Cap | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; reduce significantly in winter dormancy | Pet-safe |
| Japanese False Spleenwort | Medium indirect light (a couple of metres from a window) | Every 3–5 days in growing season; reduce slightly in winter | Mildly toxic to pets |
| Japanese Flowering Cherry Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil starts to dry, often daily in summer | Toxic to pets |
| Japanese forest grass | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Japanese Garden Juniper | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is just dry, frequently in summer | Toxic to pets |
| Japanese Holly 'Sky Pencil' | Bright indirect light (just back from a sunny window) | When the top few centimetres of soil dry; about weekly in summer | Toxic to pets |
| Japanese Holly Fern | Low light (north window or shaded room) | Every 7–10 days; allow top 2–3 cm of soil to dry between waterings | Pet-safe |
| Japanese Hornbeam | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Japanese kerria | Medium indirect light (a couple of metres from a window) | Weekly during establishment; drought-tolerant once established | Mildly toxic to pets |
| Japanese Larch | Direct sun (at least 4-6 hours) | When the surface just begins to dry, often once or twice daily in summer | Mildly toxic to pets |
| Japanese Laurel | Low light (north window or shaded room) | Once per week indoors; allow top 2–5 cm (1–2 in) of soil to dry between waterings | Mildly toxic to pets |
| Japanese Maple | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, about weekly and more in heat | Mildly toxic to pets |
| Japanese Maple 'Bloodgood' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply in dry spells | Mildly toxic to pets |
| Japanese Maple 'Crimson Queen' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, about weekly and more in heat or pots | Mildly toxic to pets |
| Japanese Maple 'Dissectum' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, often weekly in summer | Pet-safe |
| Japanese Maple 'Osakazuki' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, around weekly in dry weather | Pet-safe |
| Japanese Maple 'Sango Kaku' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly weekly in dry spells | Pet-safe |
| Japanese Maple 'Tamukeyama' | Bright indirect light (just back from a sunny window) | One to two deep waterings per week when growing | Pet-safe |
| Japanese Mazus | Direct sun (at least 4-6 hours) | Every 3–5 days; prefers moist, consistently watered soil | Mildly toxic to pets |
| Japanese Pepper Vine | Medium indirect light (a couple of metres from a window) | When the top 2–3 cm of soil dry out, approximately every 5–7 days | Mildly toxic to pets |
| Japanese Pieris | Bright indirect light (just back from a sunny window) | Keep evenly moist; water weekly in dry spells and never let it dry out | Toxic to pets |
| Japanese Pieris 'Forest Flame' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water weekly during dry spells, more in containers | Toxic to pets |
| Japanese Pieris 'Mountain Fire' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry; keep evenly moist, particularly while establishing | Toxic to pets |
| Japanese Pieris Flamingo | Bright indirect light (just back from a sunny window) | Water deeply every 7–10 days; more frequently in hot, dry spells | Toxic to pets |
| Japanese Plum Yew | Medium indirect light (a couple of metres from a window) | Keep evenly moist; weekly in dry spells, more while establishing | Mildly toxic to pets |
| Japanese Privet Bonsai | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil dries, often daily in summer | Toxic to pets |
| Japanese Quince Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Japanese Rose | Direct sun (at least 4-6 hours) | Weekly while young, then drought-tolerant once established | Pet-safe |
| Japanese Royal Fern | Medium indirect light (a couple of metres from a window) | Frequently — keep soil constantly moist | Pet-safe |
| Japanese Sage | Medium indirect light (a couple of metres from a window) | Regular during growing season; reduce in winter | Pet-safe |
| Japanese Show Lily | Bright indirect light (just back from a sunny window) | Regular during active growth, roughly every 5–7 days in dry spells; reduce after foliage dies back | Toxic to pets |
| Japanese Solomon's Seal | Medium indirect light (a couple of metres from a window) | Every 5–7 days during growth; minimal when dormant | Mildly toxic to pets |
| Japanese Spirea | Direct sun (at least 4-6 hours) | Once per week while establishing; drought-tolerant when established | Pet-safe |
| Japanese Spirea 'Anthony Waterer' | Direct sun (at least 4-6 hours) | Weekly during the first season, then only in prolonged dry spells | Mildly toxic to pets |
| Japanese Spirea 'Goldflame' | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil is dry, about weekly while establishing | Pet-safe |
| Japanese Stiff Shield Fern | Medium indirect light (a couple of metres from a window) | Weekly in the first year, then only during prolonged dry spells | Pet-safe |
| Japanese Sweet Flag | Bright indirect light (just back from a sunny window) | Keep soil consistently moist or wet; do not allow to dry out | Mildly toxic to pets |
| Japanese Timber Bamboo | Direct sun (at least 4-6 hours) | Frequent during establishment; moderate once established | Pet-safe |
| Japanese Tree Lilac | Direct sun (at least 4-6 hours) | Weekly while young, then only in drought | Mildly toxic to pets |
| Japanese Tree Lilac | Direct sun (at least 4-6 hours) | Every 7-14 days during the first two seasons; drought-tolerant once established | Mildly toxic to pets |
| Japanese Tree Lilac 'Ivory Silk' | Direct sun (at least 4-6 hours) | Weekly deep soakings for the first two years, then during droughts | Pet-safe |
| Japanese Umbrella Pine | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly weekly while young, less once established | Mildly toxic to pets |
| Japanese White Pine | Direct sun (at least 4-6 hours) | Water only when the soil surface has begun to dry; pines prefer a slightly drier regime | Mildly toxic to pets |
| Japanese White Pine 'Glauca' | Direct sun (at least 4-6 hours) | Water young trees weekly in dry weather; established trees seldom | Mildly toxic to pets |
| Japanese Witch Hazel | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-14 days in the growing season | Pet-safe |
| Japanese Wood Poppy | Medium indirect light (a couple of metres from a window) | Regular; keep soil evenly moist during the growing season | Mildly toxic to pets |
| Japanese Zelkova | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Jasminum beesianum | Direct sun (at least 4-6 hours) | Keep evenly moist while establishing; water in prolonged dry spells once mature | Pet-safe |
| Jasminum mesnyi | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| Jasminum nudiflorum | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out, about every 7-10 days while establishing | Pet-safe |
| Jelena witch hazel | Bright indirect light (just back from a sunny window) | Regularly during establishment; thereafter water during summer dry spells | Mildly toxic to pets |
| Jelena Witch Hazel | Bright indirect light (just back from a sunny window) | Deeply once or twice a week during the first growing season; established plants roughly every 10-14 days or as the top 5 cm dries | Mildly toxic to pets |
| Jelly Bean Plant | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in growth | Mildly toxic to pets |
| Jenkins Fan Palm | Bright indirect light (just back from a sunny window) | When top 2–3 cm of soil feels dry | Pet-safe |
| Jerusalem Sage | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water deeply once every 2–3 weeks in the first growing season, then rely on rainfall in most UK and Mediterranean-climate US regions. | Mildly toxic to pets |
| Joe-Pye Weed | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in dry weather | Toxic to pets |
| Johnny Jump Up | Bright indirect light (just back from a sunny window) | When the top 1–2 cm of soil is dry, roughly every 5–7 days | Mildly toxic to pets |
| Jointed Pectinaria | Direct sun (at least 4-6 hours) | Every 3–4 weeks during the growing season; almost dry in summer and winter | Mildly toxic to pets |
| Jonquil | Direct sun (at least 4-6 hours) | Moderate during autumn–spring growth; very dry during summer dormancy | Toxic to pets |
| Jordaaniella cuprea | Direct sun (at least 4-6 hours) | When the top few centimetres of soil are dry, about every 7-12 days in growth; reduce sharply in cold or dormancy | Mildly toxic to pets |
| Joseph's Lepanthes | Medium indirect light (a couple of metres from a window) | Every 7–10 days (potted); near-daily misting if mounted | Pet-safe |
| Josephine's Lily | Direct sun (at least 4-6 hours) | Water from flower-scape emergence (late summer) through leaf period (winter–spring); completely dry from late spring to late summer | Toxic to pets |
| Jubilee Celebration Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season; more in heat | Pet-safe |
| Juniper Bonsai | Direct sun (at least 4-6 hours) | When the top of the soil begins to dry, often daily in hot weather | Mildly toxic to pets |
| Juniper-leaved Thrift | Direct sun (at least 4-6 hours) | Every 10–14 days during growth; very sparingly in winter | Pet-safe |
| Juno Iris | Direct sun (at least 4-6 hours) | Moderate from early spring to late spring; completely dry mid-summer to mid-autumn | Toxic to pets |
| Jupiter's Distaff | Medium indirect light (a couple of metres from a window) | Regularly in dry spells, especially in sun | Pet-safe |
| Kaapsehoop Cycad | Bright indirect light (just back from a sunny window) | Every 1–2 weeks in summer; every 3–4 weeks in winter | Toxic to pets |
| Kahili Ginger | Bright indirect light (just back from a sunny window) | Water freely in spring and summer (every 3–5 days); reduce sharply in autumn and keep barely moist over winter | Mildly toxic to pets |
| Kamchatka Stonecrop | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is fully dry, roughly every 10-14 days; very infrequently once established | Pet-safe |
| Kangaroo Vine | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about every 7-10 days | Pet-safe |
| Karas Mountains Living Stones | Direct sun (at least 4-6 hours) | Only during the active growth window: water sparingly when new leaves are developing (roughly autumn to late spring). Withhold water entirely in summer dormancy. | Pet-safe |
| Karl Foerster Feather Reed Grass | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, roughly weekly; tolerant of occasional wet ground | Pet-safe |
| Karl Foerster Feather Reed Grass | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 2 weeks once established | Pet-safe |
| Karl Foerster Reed Grass | Bright indirect light (just back from a sunny window) | Every 7-14 days during the first season; established plants need water only in prolonged drought | Pet-safe |
| Karley Rose Fountain Grass | Direct sun (at least 4-6 hours) | Water every 7-14 days during establishment; established plants tolerate drought and need watering only in prolonged dry spells | Mildly toxic to pets |
| Karley Rose Oriental Fountain Grass | Direct sun (at least 4-6 hours) | Weekly in the first season, then moderate watering during dry periods | Pet-safe |
| Karoo Cycad | Direct sun (at least 4-6 hours) | Every 21–30 days; highly drought-tolerant once established | Toxic to pets |
| Kashmir Cypress | Direct sun (at least 4-6 hours) | Regularly; moist but well-drained | Mildly toxic to pets |
| Kashmir Gentian | Bright indirect light (just back from a sunny window) | Keep evenly moist through the growing season | Mildly toxic to pets |
| Kashmir rowan | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Katz Sakura stock | Direct sun (at least 4-6 hours) | Every 3–5 days; keep soil evenly moist but never waterlogged | Pet-safe |
| Keiske's Leucothoe | Medium indirect light (a couple of metres from a window) | Once or twice a week in the growing season, less in winter | Toxic to pets |
| Kentucky wisteria | Direct sun (at least 4-6 hours) | Weekly during the first growing season; drought-tolerant once established | Toxic to pets |
| Keteleeria davidiana | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing; established trees rely largely on rainfall with watering in drought | Mildly toxic to pets |
| Khirni | Direct sun (at least 4-6 hours) | Every 7–14 days when young; drought-tolerant once established | Pet-safe |
| Kidney Maidenhair Fern | Medium indirect light (a couple of metres from a window) | Every 3–5 days during active growth; every 6–8 days in winter | Pet-safe |
| Kidney Vetch | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Kiftsgate Rose | Direct sun (at least 4-6 hours) | Deep weekly soak while establishing; little needed once mature | Pet-safe |
| Killarney Fern | Low light (north window or shaded room) | Continuously moist — maintain permanent moisture in the sphagnum substrate and high atmospheric humidity at all times | Mildly toxic to pets |
| King Billy Pine | Bright indirect light (just back from a sunny window) | Keep consistently moist at all times; never allow to dry out, watering deeply in any dry spell | Mildly toxic to pets |
| King George aster | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; rarely needs irrigation in UK climates | Pet-safe |
| King Henry Venus flytrap | Direct sun (at least 4-6 hours) | Continuously moist via tray method; barely damp in winter | Pet-safe |
| King of Hearts Brunnera | Low light (north window or shaded room) | Keep soil consistently moist; water when the top 2-3 cm dries, about every 5-7 days in warm weather | Mildly toxic to pets |
| King Size Scarlet everlasting | Direct sun (at least 4-6 hours) | Every 7–10 days; water deeply then let soil partially dry | Pet-safe |
| Kirk's Huernia | Bright indirect light (just back from a sunny window) | Every 14–21 days when growing (spring–autumn); once monthly or less in winter | Pet-safe |
| Kitten Tails | Medium indirect light (a couple of metres from a window) | Infrequently; dry to medium-dry | Mildly toxic to pets |
| Kiwi Aeonium | Bright indirect light (just back from a sunny window) | When the top 3 cm of soil is dry, roughly every 7-12 days in active growth | Mildly toxic to pets |
| Knap Hill Scarlet quince | Bright indirect light (just back from a sunny window) | Weekly when establishing; monthly once established | Mildly toxic to pets |
| Knautia macedonica | Direct sun (at least 4-6 hours) | When the top few centimetres are dry; roughly weekly while establishing | Mildly toxic to pets |
| Kniphofia 'Alcazar' | Direct sun (at least 4-6 hours) | Weekly while establishing and during summer drought; minimal once mature | Pet-safe |
| Kniphofia 'Bees' Sunset' | Direct sun (at least 4-6 hours) | Weekly while establishing and during drought; little once mature | Pet-safe |
| Kniphofia 'Little Maid' | Direct sun (at least 4-6 hours) | Weekly while establishing and in summer drought; sparing once settled | Pet-safe |
| Kniphofia 'Tawny King' | Direct sun (at least 4-6 hours) | Weekly during the first season and in summer drought; established clumps need little once settled | Pet-safe |
| Kniphofia triangularis | Direct sun (at least 4-6 hours) | Every 10-14 days once established, when soil is dry | Pet-safe |
| Kniphofia uvaria | Direct sun (at least 4-6 hours) | Water regularly through the first season, then mainly in summer dry spells once established | Pet-safe |
| Knock Out Rose | Direct sun (at least 4-6 hours) | About 2.5 cm of water weekly, deep soak | Pet-safe |
| Knotted Clover | Direct sun (at least 4-6 hours) | Low; drought-tolerant | Pet-safe |
| Kobus Magnolia | Direct sun (at least 4-6 hours) | Weekly when establishing; once established, natural rainfall is often sufficient except during prolonged drought | Pet-safe |
| Koehne's rowan | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Koelreuteria paniculata | Direct sun (at least 4-6 hours) | Weekly for the first 1-2 years; minimal once established | Mildly toxic to pets |
| Kolkwitzia amabilis | Direct sun (at least 4-6 hours) | Weekly while establishing, then in dry spells | Mildly toxic to pets |
| Kolkwitzia amabilis 'Pink Cloud' | Direct sun (at least 4-6 hours) | Weekly during the first two growing seasons; established plants only in prolonged drought | Mildly toxic to pets |
| Korean Angelica | Medium indirect light (a couple of metres from a window) | 2-3 times per week in active growth; reduce in winter | Mildly toxic to pets |
| Korean feather reed grass | Bright indirect light (just back from a sunny window) | Water deeply 1-2 times weekly; keep soil consistently moist but not waterlogged | Pet-safe |
| Korean Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; moderately drought-tolerant once mature | Pet-safe |
| Korean Hornbeam | Direct sun (at least 4-6 hours) | When the top 1-2 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Korean Hornbeam Bonsai | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil starts to dry, often daily in summer | Mildly toxic to pets |
| Korean rhododendron | Bright indirect light (just back from a sunny window) | Weekly during establishment and summer; reduce to monthly when dormant | Toxic to pets |
| Korean Rock Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days in growing season; reduce in winter | Pet-safe |
| Korean Spice Viburnum | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil is dry, about weekly while establishing | Pet-safe |
| Kousa Dogwood | Bright indirect light (just back from a sunny window) | Weekly deep watering while establishing | Pet-safe |
| Krossa Regal Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Kuma Bamboo Grass | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season, reduce in winter | Pet-safe |
| Kurume Azalea 'Hino Crimson' | Bright indirect light (just back from a sunny window) | About weekly once established, more in heat; water when the top 2-3 cm of soil is dry | Toxic to pets |
| Küster's Ceratozamia | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season; every 3–5 weeks in winter | Toxic to pets |
| Labrador violet | Medium indirect light (a couple of metres from a window) | Every 5–7 days; keep consistently moist | Pet-safe |
| Laburnum × watereri 'Vossii' | Direct sun (at least 4-6 hours) | Water weekly through the first two seasons, then only in prolonged drought | Toxic to pets |
| Lace Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; dry rest in winter | Mildly toxic to pets |
| Lace Fern | Bright indirect light (just back from a sunny window) | When the soil is completely dry, approximately every 10-21 days depending on temperature and season | Pet-safe |
| Lace-bark Pine | Direct sun (at least 4-6 hours) | Water young trees weekly in dry spells; established trees rarely | Mildly toxic to pets |
| Lacecap Hydrangea | Bright indirect light (just back from a sunny window) | When the top 2-4 cm of soil is dry, often several times a week in heat | Toxic to pets |
| Laced Up Elderberry | Direct sun (at least 4-6 hours) | Weekly for the first 1–2 seasons; every 10–14 days once established | Mildly toxic to pets |
| Laceleaf Japanese Maple 'Crimson Queen' | Bright indirect light (just back from a sunny window) | Deeply once or twice a week in the growing season, more in heat | Pet-safe |
| Lady Fern | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil starts to dry, roughly every 3-5 days indoors | Pet-safe |
| Lady in Red Fern | Medium indirect light (a couple of metres from a window) | Keep consistently moist, roughly every 3-5 days for potted plants | Mildly toxic to pets |
| Lady of Shalott Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat or sandy soil | Pet-safe |
| Lady of the Night | Bright indirect light (just back from a sunny window) | Every 5–7 days; adjust based on season and soil moisture | Toxic to pets |
| Lady Slipper Orchid | Bright indirect light (just back from a sunny window) | Every 5-10 days; keep the medium evenly moist | Mildly toxic to pets |
| Laelia anceps | Bright indirect light (just back from a sunny window) | Every 5-7 days when growing; reduce sharply through winter rest | Pet-safe |
| Laelia gouldiana | Bright indirect light (just back from a sunny window) | Every 5-7 days in growth; sparingly through the dry winter rest | Pet-safe |
| Laguna Beach Liveforever | Bright indirect light (just back from a sunny window) | Every 10–14 days from autumn through spring; withhold almost entirely in summer | Pet-safe |
| Lamance Iris | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; tolerates seasonal flooding of 5–10 cm (2–4 in) for short periods. | Toxic to pets |
| Lamb's Ear | Direct sun (at least 4-6 hours) | Low; water only when soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Lamb's Stomatium | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; once monthly or less in winter | Mildly toxic to pets |
| Lamellate Rainbow Plant | Direct sun (at least 4-6 hours) | Top-water only; moist in cool season, near-dry in summer | Pet-safe |
| Lamprocapnos spectabilis 'Alba' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil begins to dry, roughly every 5-7 days in spring | Toxic to pets |
| Lamprocapnos spectabilis 'Gold Heart' | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil begins to dry, roughly every 5-7 days in spring | Toxic to pets |
| Lance-leaf Liveforever | Bright indirect light (just back from a sunny window) | Every 10–14 days in winter and spring (active season); withhold almost entirely in summer | Pet-safe |
| Lance-leaf Stelis | Medium indirect light (a couple of metres from a window) | Every 2–3 days; never allow the medium to dry completely | Pet-safe |
| Lance-Leaved Trillium | Medium indirect light (a couple of metres from a window) | Moist in spring; more drought-tolerant than most Trilliums once dormant | Mildly toxic to pets |
| Lance-leaved Water Plantain | Direct sun (at least 4-6 hours) | Permanently waterlogged to submerged; 5–30 cm (2–12 in) water depth | Mildly toxic to pets |
| Lansberg's Restrepia | Bright indirect light (just back from a sunny window) | Every 2-4 days; evenly moist but not waterlogged | Pet-safe |
| Lantana | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil is dry; roughly weekly in summer, less in cooler weather | Toxic to pets |
| Lapidaria margaretae | Direct sun (at least 4-6 hours) | Soak only in autumn and early spring growth; keep bone-dry through summer and deep winter | Mildly toxic to pets |
| large blue fescue | Direct sun (at least 4-6 hours) | Low to moderate; water every 7–10 days during active growth, monthly once established | Pet-safe |
| Large Chain Orchid | Bright indirect light (just back from a sunny window) | Every 5-7 days during active growth; reduce to every 10-14 days in winter | Pet-safe |
| Large Masterwort | Medium indirect light (a couple of metres from a window) | Every 5-7 days; soil should remain evenly moist throughout the growing season | Mildly toxic to pets |
| Large-cloaked Stelis | Medium indirect light (a couple of metres from a window) | Every 1–2 days, never allowing the medium to dry completely | Pet-safe |
| Large-flowered Bacopa | Direct sun (at least 4-6 hours) | Keep soil evenly and consistently moist | Mildly toxic to pets |
| large-flowered butterwort | Bright indirect light (just back from a sunny window) | Keep soil permanently damp during growing season; reduce but do not dry out completely in winter | Pet-safe |
| Large-Flowered Copiapoa | Direct sun (at least 4-6 hours) | Every 14-21 days in summer; once a month or dry in winter | Pet-safe |
| Large-Flowered Maxillaria | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 7–10 days in cooler months | Pet-safe |
| Large-Flowered Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growth; sparingly in winter | Pet-safe |
| Large-flowered Rain Lily | Direct sun (at least 4-6 hours) | Allow partial drying between waterings; a dry-wet cycle triggers blooming | Toxic to pets |
| Large-flowered Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season (autumn–spring); monthly or less in summer | Toxic to pets |
| Larkspur | Direct sun (at least 4-6 hours) | Every 5–7 days | Toxic to pets |
| Late Tulip | Direct sun (at least 4-6 hours) | Rainfall-dependent during spring growth; needs dry summer rest | Toxic to pets |
| Lau's Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 5-6 weeks in winter | Pet-safe |
| Lau's Turbinicarpus | Direct sun (at least 4-6 hours) | When soil is completely dry, approximately every 14-21 days in summer; minimal or no water in winter | Pet-safe |
| Laurel-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; weekly in the first season | Mildly toxic to pets |
| Lauren's Grape peony poppy | Direct sun (at least 4-6 hours) | Weekly during establishment; every 10–14 days once plants are growing strongly | Toxic to pets |
| Laurustinus Viburnum | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil is dry; weekly while establishing, then occasional | Pet-safe |
| Lavender trumpet vine | Bright indirect light (just back from a sunny window) | Weekly during the growing and flowering season; every 2–3 weeks in summer and winter. | Mildly toxic to pets |
| Lavender-leaved Sage | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 3–4 weeks in winter | Mildly toxic to pets |
| Lawrence's Coelogyne | Bright indirect light (just back from a sunny window) | Every 5-7 days during active growth; reduce to every 14-21 days in winter when temperatures are cooler | Pet-safe |
| Leaf-Spined Brain Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-14 days during summer; once every 4-6 weeks in winter | Pet-safe |
| Least Primrose | Direct sun (at least 4-6 hours) | Every 7–10 days during active growth; very sparingly in summer and winter | Mildly toxic to pets |
| Least Yellow Pond Lily | Bright indirect light (just back from a sunny window) | Permanently submerged — thrives at water depths of 30–100 cm (1–3 ft). | Mildly toxic to pets |
| Least Yellow Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic; plant at 20–60 cm (8–24 in) water depth | Mildly toxic to pets |
| Leather Polypody | Medium indirect light (a couple of metres from a window) | Every 5–8 days; keep soil consistently moist but not waterlogged | Mildly toxic to pets |
| Leatherleaf Sedge | Direct sun (at least 4-6 hours) | Water weekly while establishing in year one, then only during prolonged dry spells | Mildly toxic to pets |
| leatherleaf viburnum | Bright indirect light (just back from a sunny window) | Weekly when establishing; every 2–4 weeks once mature | Mildly toxic to pets |
| Leathery Polypody | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growing season; monthly in winter dormancy | Pet-safe |
| Lebanese Rosularia | Bright indirect light (just back from a sunny window) | Every 2–4 weeks in growing season; monthly or less in winter | Pet-safe |
| Lehmann's Ice Plant | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in spring-summer; very sparingly in winter (once every 3-4 weeks) | Pet-safe |
| Lemboglossum rossii | Bright indirect light (just back from a sunny window) | Water when the bark approaches dryness, roughly every 4-7 days, keeping pseudobulbs plump | Pet-safe |
| Lemmon's marigold | Direct sun (at least 4-6 hours) | Every 7–10 days in summer heat; monthly during cool winter dormancy | Mildly toxic to pets |
| Lemna minor | Bright indirect light (just back from a sunny window) | Floats permanently on still or slow water; no separate watering | Mildly toxic to pets |
| Leopard Plant 'Desdemona' | Medium indirect light (a couple of metres from a window) | Every 3-5 days in warm weather; keep soil consistently moist or wet | Mildly toxic to pets |
| Leopard Plant 'The Rocket' | Medium indirect light (a couple of metres from a window) | Every 3-5 days or more frequently in warm weather; soil should remain consistently moist | Mildly toxic to pets |
| lesser bladderwort | Bright indirect light (just back from a sunny window) | Permanently submerged or floating in shallow standing water | Pet-safe |
| Lesser Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 7–10 days in active growth; reduce significantly in winter | Pet-safe |
| Lesser Pond Sedge | Direct sun (at least 4-6 hours) | Permanently wet; waterlogged soil or up to 20 cm of standing water | Pet-safe |
| Lesser Quaking Grass | Direct sun (at least 4-6 hours) | Water sparingly; keep soil evenly moist during germination and establishment | Pet-safe |
| Lesser Sea Spurrey | Direct sun (at least 4-6 hours) | Low; tolerates periods of drought punctuated by brackish flooding | Mildly toxic to pets |
| Lesser Spearwort | Direct sun (at least 4-6 hours) | Saturated mud to 5 cm standing water | Toxic to pets |
| Lesser Stitchwort | Bright indirect light (just back from a sunny window) | Moderate; keep soil consistently moist but never waterlogged | Mildly toxic to pets |
| Lesser Water Plantain | Direct sun (at least 4-6 hours) | Saturated to 10 cm depth of water | Pet-safe |
| Leucanthemum × superbum 'Alaska' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly weekly; more in extended heat | Toxic to pets |
| Leucanthemum × superbum 'Becky' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly weekly; more in prolonged heat | Toxic to pets |
| Leucanthemum × superbum 'Silver Princess' | Direct sun (at least 4-6 hours) | About once a week, when the top 3-4 cm of soil is dry | Toxic to pets |
| Leucanthemum × superbum 'Snowcap' | Direct sun (at least 4-6 hours) | About once a week, when the top 3-4 cm of soil is dry | Toxic to pets |
| Leucanthemum × superbum 'Wirral Supreme' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about weekly; more during drought | Toxic to pets |
| Levy's Huernia | Bright indirect light (just back from a sunny window) | Every 14–21 days during active growth (spring–autumn); once monthly or less in winter | Pet-safe |
| Leyland Cypress | Direct sun (at least 4-6 hours) | Weekly during the first two years, then only in prolonged drought | Mildly toxic to pets |
| Liatris spicata | Direct sun (at least 4-6 hours) | When the top 3-4 cm is dry; roughly weekly while establishing | Pet-safe |
| Liatris spicata 'Kobold' | Direct sun (at least 4-6 hours) | When the top 3-4 cm is dry; about weekly while establishing | Pet-safe |
| Licorice Fern | Bright indirect light (just back from a sunny window) | Keep evenly moist while in active growth (fall through spring); water when the surface just begins to dry | Pet-safe |
| Licorice plant | Bright indirect light (just back from a sunny window) | Every 7–14 days; allow top 2–3 cm to dry | Pet-safe |
| Lilac 'Charles Joly' | Direct sun (at least 4-6 hours) | Weekly through the first season, then only in drought | Mildly toxic to pets |
| Lilac Sage | Bright indirect light (just back from a sunny window) | Water when the top 5 cm of soil is dry | Pet-safe |
| Lilac Trumpet Vine | Direct sun (at least 4-6 hours) | Water every 7-10 days during the growing season, allowing the top 3-5 cm to dry slightly between waterings; reduce to every 2-3 weeks in cooler months | Mildly toxic to pets |
| Lilafee Epimedium | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly | Mildly toxic to pets |
| Lily Magnolia | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce in autumn and winter | Pet-safe |
| Lily of the valley | Low light (north window or shaded room) | Weekly watering | Toxic to pets |
| Lime Rickey Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about weekly | Pet-safe |
| Limestone Oak Fern | Bright indirect light (just back from a sunny window) | Keep moist but never waterlogged; water when the top 2 cm dries, roughly weekly in dry spells | Mildly toxic to pets |
| Linaria maroccana 'Fairy Bouquet' | Direct sun (at least 4-6 hours) | When the top 2 cm of soil is dry, roughly every 4-7 days | Mildly toxic to pets |
| Liquidambar styraciflua | Direct sun (at least 4-6 hours) | Weekly while establishing; keep soil consistently moist | Mildly toxic to pets |
| Liquidambar styraciflua 'Worplesdon' | Direct sun (at least 4-6 hours) | Weekly while establishing; keep soil consistently moist | Mildly toxic to pets |
| Liriodendron tulipifera | Direct sun (at least 4-6 hours) | Deep soak weekly in the first two or three growing seasons, then rely on rainfall | Pet-safe |
| Lithops Pseudotruncatella | Direct sun (at least 4-6 hours) | Very infrequently, following the seasonal cycle rather than a fixed schedule | Pet-safe |
| Little Bunny Fountain Grass | Direct sun (at least 4-6 hours) | Weekly while establishing in the first season, then only during prolonged drought | Pet-safe |
| Little Calyx Aechmea | Bright indirect light (just back from a sunny window) | Every 7–10 days in growing season | Pet-safe |
| Little Gem Magnolia | Direct sun (at least 4-6 hours) | Weekly while establishing (1–3 years); deep watering in summer drought thereafter | Pet-safe |
| Little Gem Spruce | Direct sun (at least 4-6 hours) | Every 5-7 days; keep the small root zone evenly moist, watering when the surface dries | Pet-safe |
| Little Hard Fern | Medium indirect light (a couple of metres from a window) | 2-3 times per week in the growing season; less often in winter | Pet-safe |
| Little Heath pieris | Bright indirect light (just back from a sunny window) | Weekly; maintain consistent moisture | Toxic to pets |
| Little Kitten Dwarf Maiden Grass | Direct sun (at least 4-6 hours) | Weekly to establish, then during dry spells; container plants need more frequent water | Mildly toxic to pets |
| Little Leather Lepanthes | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; keep roots evenly moist | Pet-safe |
| Little Sweet Betsy | Medium indirect light (a couple of metres from a window) | Consistently moist from emergence through early summer; reduced in summer dormancy | Mildly toxic to pets |
| Living Rock Cactus | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 21-30 days in summer; essentially none in winter | Pet-safe |
| Lobbi Japanese Cedar | Direct sun (at least 4-6 hours) | Weekly during establishment; fortnightly in dry spells once mature | Mildly toxic to pets |
| Lobed Tickseed | Bright indirect light (just back from a sunny window) | Low to moderate; drought-tolerant but benefits from occasional watering | Pet-safe |
| Lobelia cardinalis | Direct sun (at least 4-6 hours) | Keep consistently moist to wet; never let it dry out | Toxic to pets |
| Lobelia erinus 'Cascade Blue' | Direct sun (at least 4-6 hours) | Keep consistently moist; check baskets daily in warm weather | Toxic to pets |
| Lobelia erinus 'Riviera Lilac' | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the surface starts to dry | Toxic to pets |
| Lobelia siphilitica | Direct sun (at least 4-6 hours) | Keep consistently moist; tolerates wet soil and short dry spells | Toxic to pets |
| Lobivia famatimensis | Direct sun (at least 4-6 hours) | Water thoroughly when the mix dries out, roughly every 1-2 weeks in summer; keep dry through winter | Pet-safe |
| Loblolly Pine Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm is dry, commonly daily in summer and every 3-5 days in cool weather | Pet-safe |
| Lobster Flower | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in summer; monthly or less in winter | Pet-safe |
| London Pride | Medium indirect light (a couple of metres from a window) | Every 5–7 days in the growing season; less in winter | Pet-safe |
| London Pride | Medium indirect light (a couple of metres from a window) | Weekly during dry spells; little additional watering needed in temperate climates | Pet-safe |
| Long Eye-leaf | Direct sun (at least 4-6 hours) | Every 14-21 days during the autumn-to-spring growing season when the old body wrinkles; completely dry from late spring through summer | Mildly toxic to pets |
| Long-Beaked Stork's Bill | Direct sun (at least 4-6 hours) | Water lightly during the cooler growing season; minimal water needed in summer | Mildly toxic to pets |
| Long-flowered Sage | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; rarely in winter | Mildly toxic to pets |
| Long-Haired Zygopetalum | Bright indirect light (just back from a sunny window) | Every 3–4 days in growth, reduce to weekly in winter | Pet-safe |
| Long-Leaf Wax Plant | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season, monthly in winter | Pet-safe |
| Long-Leaved Pachyphytum | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; every 4–6 weeks in autumn and winter | Pet-safe |
| Long-leaved Pelargonium | Direct sun (at least 4-6 hours) | Water moderately during active growth (autumn–spring); withhold almost entirely in summer dormancy | Toxic to pets |
| Long-Leaved Phlomis | Direct sun (at least 4-6 hours) | Low — water every 2–3 weeks during the growing season; minimal to none in winter | Mildly toxic to pets |
| Long-leaved speedwell | Direct sun (at least 4-6 hours) | Weekly during the growing season; reduce in winter | Pet-safe |
| Long-lipped Tongue Orchid | Direct sun (at least 4-6 hours) | Winter-wet, summer-dry cycle; water lightly in autumn through spring, withhold completely in summer | Mildly toxic to pets |
| Long-Petaled Deuterocohnia | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer; monthly or less in winter | Pet-safe |
| Long-Petalled Lewisia | Bright indirect light (just back from a sunny window) | Moderate in spring; almost dry in summer dormancy | Mildly toxic to pets |
| Long-Spurred Violet | Medium indirect light (a couple of metres from a window) | Regular; keep soil evenly moist | Pet-safe |
| Long-Stalked Cranesbill | Direct sun (at least 4-6 hours) | Low; tolerates extended dry periods | Pet-safe |
| Long-stamen Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Pet-safe |
| Long-stamened Sage | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries out, roughly every 5-8 days in summer | Pet-safe |
| Long-styled Sage | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; very sparingly in winter | Mildly toxic to pets |
| Long-tailed Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in warm months; every 1-2 days in cool months — medium must not dry out between waterings | Pet-safe |
| Long-tongue Tongue Plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer; monthly or less in winter | Mildly toxic to pets |
| Longcluster Japanese Wisteria | Direct sun (at least 4-6 hours) | Every 7–14 days during dry periods; established plants need little supplemental watering | Toxic to pets |
| Lonicera caprifolium | Direct sun (at least 4-6 hours) | Keep the root zone evenly moist; water deeply in dry spells, every 5-7 days in summer heat | Mildly toxic to pets |
| Lonicera japonica | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, around every 5-10 days while establishing | Mildly toxic to pets |
| Lonicera periclymenum | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil dries, roughly every 5-10 days while establishing | Mildly toxic to pets |
| Lonicera periclymenum 'Serotina' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil dries, roughly every 5-10 days while establishing | Mildly toxic to pets |
| Lonicera sempervirens | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, about every 5-10 days while establishing | Mildly toxic to pets |
| Lonicera x heckrottii | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, about every 5-10 days while establishing | Mildly toxic to pets |
| Loose Aichryson | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; every 4–6 weeks in winter | Mildly toxic to pets |
| Loose Puya | Direct sun (at least 4-6 hours) | When the soil is dry to at least 4 cm depth, roughly every 14-21 days in summer; almost nothing in winter | Mildly toxic to pets |
| Loose-flowered Monanthes | Bright indirect light (just back from a sunny window) | Every 2–4 weeks in spring and summer; every 4–6 weeks or less in winter | Mildly toxic to pets |
| Loranthus-leaf Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 2-3 days; keep evenly moist | Pet-safe |
| Lords-and-Ladies | Low light (north window or shaded room) | Weekly during active growth (autumn–spring); reduce in summer dormancy | Toxic to pets |
| Lorentz's Deuterocohnia | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 14-21 days in the growing season; minimal in winter | Pet-safe |
| Lossow's Jensenobotrya | Bright indirect light (just back from a sunny window) | Water sparingly year-round, every 2–3 weeks | Toxic to pets |
| Lotax Dragon Orchid | Medium indirect light (a couple of metres from a window) | Every 2–3 days; never fully dry | Pet-safe |
| Love-in-a-mist | Direct sun (at least 4-6 hours) | Once or twice a week; established plants rarely need supplemental watering in cool, moist climates | Toxic to pets |
| Low's Cymbidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce in winter | Pet-safe |
| Low's Cymbidium | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of the compost is dry, roughly every 5-7 days in active growth | Pet-safe |
| Lowii Pitcher Plant | Bright indirect light (just back from a sunny window) | Keep mix moist, watering every few days; never let it dry out or stand flooded | Pet-safe |
| Lowland Brittle Fern | Medium indirect light (a couple of metres from a window) | Moderate — keep evenly moist, allowing the surface to just dry between waterings | Mildly toxic to pets |
| Lucky Nut | Direct sun (at least 4-6 hours) | Every 5–10 days during establishment; drought-tolerant once established | Toxic to pets |
| Lucuma | Direct sun (at least 4-6 hours) | Every 7–14 days; allow top 5–8 cm to dry between waterings | Mildly toxic to pets |
| Lungwort 'Bertram Anderson' | Medium indirect light (a couple of metres from a window) | Every 7-10 days; somewhat more drought-tolerant than other pulmonarias but still prefers consistent moisture | Pet-safe |
| Lungwort 'Mrs Moon' | Medium indirect light (a couple of metres from a window) | Every 5-7 days in the growing season; keep soil moist but not waterlogged | Pet-safe |
| Lungwort Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry spells, more in containers | Mildly toxic to pets |
| Lupin 'The Governor' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Lupine | Direct sun (at least 4-6 hours) | Weekly watering | Toxic to pets |
| Lupinus 'Chandelier' | Direct sun (at least 4-6 hours) | Every 5-7 days; keep the soil evenly moist, never sodden | Toxic to pets |
| Lupinus 'Manhattan Lights' | Direct sun (at least 4-6 hours) | Every 5-7 days; keep soil consistently moist but well-drained | Toxic to pets |
| Lupinus 'Masterpiece' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply once or twice weekly in dry spells | Toxic to pets |
| Lupinus 'Tequila Flame' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; deep water once or twice weekly when dry | Toxic to pets |
| Lupinus 'The Governor' | Direct sun (at least 4-6 hours) | Every 5-7 days; keep soil consistently moist, never waterlogged | Toxic to pets |
| Lupinus polyphyllus 'Gallery Blue' | Direct sun (at least 4-6 hours) | Every 5-7 days; maintain evenly moist soil without waterlogging | Toxic to pets |
| Lurida Cast Iron Plant | Low light (north window or shaded room) | When the top half of the soil is dry, roughly every 10-14 days | Toxic to pets |
| Ly's Wax Plant | Medium indirect light (a couple of metres from a window) | Every 7–10 days in summer, every 14–21 days in winter | Pet-safe |
| Lycaste aromatica | Bright indirect light (just back from a sunny window) | Every 4-6 days while in leaf; sparingly once leaves drop | Pet-safe |
| Lycaste skinneri | Bright indirect light (just back from a sunny window) | Every 5-7 days in active growth; reduce sharply after leaf drop, roughly every 2-3 weeks in winter rest | Pet-safe |
| Lycian Sage Phlomis | Direct sun (at least 4-6 hours) | Low — every 2–3 weeks in the growing season; minimal to none in winter | Mildly toxic to pets |
| Lydia's Eye-leaf | Direct sun (at least 4-6 hours) | Every 14-21 days in autumn through spring when the body wrinkles; none at all from late spring through summer | Mildly toxic to pets |
| Lydia's Window Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (September–March in the Northern Hemisphere); essentially none in summer | Mildly toxic to pets |
| Lydian Broom | Direct sun (at least 4-6 hours) | Low — drought-tolerant; water only to establish | Toxic to pets |
| Lydian Stonecrop | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly or less in winter | Pet-safe |
| Lyme Grass | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Lysimachia nummularia | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water whenever the surface begins to dry | Mildly toxic to pets |
| Lysimachia nummularia 'Aurea' | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water whenever the surface starts to dry | Mildly toxic to pets |
| Lythrum salicaria | Direct sun (at least 4-6 hours) | Keep wet; thrives in saturated soil and shallow water | Mildly toxic to pets |
| Macarthur Palm | Medium indirect light (a couple of metres from a window) | Every 5–7 days during growing season; reduce in cooler months | Pet-safe |
| MacDonnell Ranges Cycad | Direct sun (at least 4-6 hours) | Every 3–4 weeks (established); monthly or less in winter | Toxic to pets |
| Madame Alfred Carriere Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly when establishing; mature plants when the top few centimetres of soil dry, and they tolerate some drought | Pet-safe |
| Madame Butterfly snapdragon | Direct sun (at least 4-6 hours) | Every 5–7 days; keep evenly moist | Pet-safe |
| Madame Galen Trumpet Vine | Direct sun (at least 4-6 hours) | Weekly when young; drought-tolerant once established | Mildly toxic to pets |
| Madame Lemoine Lilac | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days; established plants are drought-tolerant | Pet-safe |
| Madison's Matucana | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, every 10-14 days in summer | Pet-safe |
| Madonna White Snapdragon | Direct sun (at least 4-6 hours) | When the top 2–3 cm of soil is dry, roughly every 5–7 days | Pet-safe |
| Magdalene's Angraecum | Bright indirect light (just back from a sunny window) | Every 5-7 days in active growth; reduce to every 14-21 days in winter | Pet-safe |
| Magenta Cherry | Direct sun (at least 4-6 hours) | Every 5–7 days in the growing season; reduce to every 10–14 days in winter | Mildly toxic to pets |
| Magnificent Inula | Bright indirect light (just back from a sunny window) | 2-3 times per week; tolerates moist to wet conditions | Pet-safe |
| Magnificent Juno Iris | Direct sun (at least 4-6 hours) | Moderate in growth; dry in summer dormancy | Toxic to pets |
| Magnolia 'Elizabeth' | Direct sun (at least 4-6 hours) | Weekly during the first few years and in summer droughts | Pet-safe |
| Magnolia 'Jane' | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the first two years, then during dry spells | Pet-safe |
| Magnolia 'Susan' | Direct sun (at least 4-6 hours) | Keep moist while establishing; water deeply weekly in dry spells for the first few years | Pet-safe |
| Magnolia grandiflora 'Gallissonnière' | Direct sun (at least 4-6 hours) | Weekly deep watering in the first 2-3 years, then only during prolonged dry spells | Pet-safe |
| Magnolia wilsonii | Bright indirect light (just back from a sunny window) | Weekly while establishing and during dry summer spells | Pet-safe |
| Magnolia-leaved Sage | Bright indirect light (just back from a sunny window) | Weekly in summer; every 2–3 weeks in winter | Mildly toxic to pets |
| Mahonia aquifolium Apollo | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, weekly through the first year then occasionally | Pet-safe |
| Mahonia Charity | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, weekly to establish then chiefly during droughts | Pet-safe |
| Mahonia Pinnacle | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, weekly through the first year then occasionally | Pet-safe |
| Mahonia repens | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, weekly to establish then rarely | Pet-safe |
| Mahonia Soft Caress | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, about weekly and more attentively than spinier mahonias | Pet-safe |
| Mahonia Winter Sun | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, weekly while establishing then only in dry spells | Pet-safe |
| Maiden Grass | Direct sun (at least 4-6 hours) | Weekly during the first growing season; every 2–3 weeks once established | Pet-safe |
| Maidenhair Spleenwort | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Maidenhair Tree | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil dries, roughly every 1-3 days in summer | Mildly toxic to pets |
| Maire's fescue | Direct sun (at least 4-6 hours) | Low; water every 2–3 weeks during dry spells; once established, relies on natural rainfall in most temperate climates | Pet-safe |
| Majeste Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry weather, more for containers | Mildly toxic to pets |
| Majestic Giants Pansy | Bright indirect light (just back from a sunny window) | When the top 1–2 cm of soil starts to dry, roughly every 3–5 days in mild weather | Mildly toxic to pets |
| Male Fern | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Maltese cross | Direct sun (at least 4-6 hours) | Every 5–7 days in the growing season; less in cool or wet periods | Pet-safe |
| Malus 'Profusion' | Direct sun (at least 4-6 hours) | Water regularly while establishing; mature trees need water only in prolonged drought | Toxic to pets |
| Malus 'Royalty' | Direct sun (at least 4-6 hours) | Water regularly for the first 2-3 years; established trees need water only in extended drought | Toxic to pets |
| Malus floribunda | Direct sun (at least 4-6 hours) | Water regularly during establishment; mature trees need water only in extended drought | Toxic to pets |
| Malus tschonoskii | Direct sun (at least 4-6 hours) | Water regularly for the first 2-3 years; established trees need water only in prolonged drought | Toxic to pets |
| Mammillaria bombycina | Direct sun (at least 4-6 hours) | Water thoroughly when the soil is fully dry, roughly every 1-2 weeks in summer; keep nearly dry in winter | Pet-safe |
| Mammillaria mystax | Direct sun (at least 4-6 hours) | Water deeply when the mix is completely dry, about every 1-2 weeks in summer; keep dry in winter | Pet-safe |
| Mandacaru Cactus | Direct sun (at least 4-6 hours) | Every 2-3 weeks in the growing season (spring–summer); every 4-6 weeks in autumn; once every 6-8 weeks in winter | Mildly toxic to pets |
| Manhattan Euonymus | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Manica Cycad | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; every 3–4 weeks in winter | Toxic to pets |
| Manna Ash | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Pet-safe |
| Many Fingers | Direct sun (at least 4-6 hours) | Every 2 weeks in spring and summer; every 4–6 weeks in autumn and winter | Pet-safe |
| Many-Flowered Air Plant | Bright indirect light (just back from a sunny window) | Mist 1–2 times per week, or a 20-minute soak every 1–2 weeks | Pet-safe |
| Many-Flowered Cornflag | Direct sun (at least 4-6 hours) | Weekly during autumn-to-spring growing season; dry in summer dormancy | Mildly toxic to pets |
| Many-flowered Fockea | Bright indirect light (just back from a sunny window) | Every 10–14 days in summer; monthly or less in winter | Mildly toxic to pets |
| Many-Flowered Ruschia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season (autumn–spring); very sparingly in summer | Mildly toxic to pets |
| Many-Flowered Rush | Direct sun (at least 4-6 hours) | Frequent to constant — prefers permanently moist to wet soil | Pet-safe |
| Many-haired Draba | Direct sun (at least 4-6 hours) | Every 10–14 days during growth; almost dry in winter | Pet-safe |
| Many-Headed Barrel Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and essentially none in winter | Pet-safe |
| Many-Nippled Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, approximately every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Many-pinnate Cycad | Bright indirect light (just back from a sunny window) | Every 10–14 days in summer; every 3–5 weeks in winter | Toxic to pets |
| Many-spiked Ixia | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry during active growth, roughly every 10-14 days | Toxic to pets |
| Many-spiked Sage | Direct sun (at least 4-6 hours) | Moderate; water when the top 5 cm of soil is dry | Mildly toxic to pets |
| Many-stemmed Liveforever | Direct sun (at least 4-6 hours) | Every 2–3 weeks autumn through late spring; none in summer | Pet-safe |
| Marbled Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during the autumn-to-spring active period; completely dry in summer | Pet-safe |
| Marbled Living Stones | Direct sun (at least 4-6 hours) | Seasonally — water only in autumn during new-leaf emergence (September–November); completely dry rest of year | Pet-safe |
| Marginal Wood Fern | Low light (north window or shaded room) | Keep evenly moist while establishing; water deeply during droughts, about every 7-10 days in dry summers | Pet-safe |
| Margined Copiapoa | Direct sun (at least 4-6 hours) | When the soil is completely dry throughout, roughly every 14-21 days in summer; monthly or less in winter | Pet-safe |
| Margined Saxifrage | Bright indirect light (just back from a sunny window) | Every 7–10 days when growing; very sparingly in winter | Pet-safe |
| Marie Simon Ceanothus | Direct sun (at least 4-6 hours) | Every 7-10 days in the growing season, allowing the top few centimetres of soil to dry between waterings; less in winter | Mildly toxic to pets |
| Marie's Davallia | Bright indirect light (just back from a sunny window) | Every 5–10 days in the growing season; minimal in winter dormancy | Pet-safe |
| Maritime Zamia | Direct sun (at least 4-6 hours) | Every 14–21 days in the growing season; once a month or less in winter | Toxic to pets |
| Marmalade Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly | Pet-safe |
| Marram Grass | Direct sun (at least 4-6 hours) | Low; drought-tolerant | Pet-safe |
| Marseille Germander | Direct sun (at least 4-6 hours) | Infrequently once established; weekly when newly planted | Mildly toxic to pets |
| Marsh Afrikaner | Direct sun (at least 4-6 hours) | Moderate during winter–spring growing season; withhold entirely once foliage dies back in summer | Toxic to pets |
| Marsh Fern | Bright indirect light (just back from a sunny window) | Keep wet to saturated at all times; never allow the soil to dry out | Mildly toxic to pets |
| Marson's Crown Cactus | Direct sun (at least 4-6 hours) | Every 7-14 days in active growth; once every 4-6 weeks in winter | Pet-safe |
| Marson's Gymnocalycium | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-12 days in summer; monthly or less in winter | Pet-safe |
| Martagon Lily | Medium indirect light (a couple of metres from a window) | When top 3–4 cm of soil feels dry | Toxic to pets |
| Martinezii Lily | Direct sun (at least 4-6 hours) | Dry in summer; moderate in winter-to-spring growth period | Toxic to pets |
| Martius Fan Palm | Direct sun (at least 4-6 hours) | Weekly during establishment; once established, every 2–3 weeks depending on rainfall | Pet-safe |
| Mary's Prosthechea | Bright indirect light (just back from a sunny window) | Every 5-7 days in growth; every 14-21 days in winter | Pet-safe |
| Masdevallia coccinea | Medium indirect light (a couple of metres from a window) | Keep evenly moist all year, watering about every 2-4 days so the medium never dries fully | Pet-safe |
| Masdevallia veitchiana | Medium indirect light (a couple of metres from a window) | Keep roots evenly moist year-round; water roughly every 2-4 days so the mix never fully dries | Pet-safe |
| Masked Twinspur | Bright indirect light (just back from a sunny window) | Water regularly to keep soil evenly moist | Mildly toxic to pets |
| Masters' Larch | Direct sun (at least 4-6 hours) | Weekly during first 2 years; monthly once established | Pet-safe |
| Masterwort 'Ruby Wedding' | Medium indirect light (a couple of metres from a window) | Every 5-7 days in warm weather; reduce in cooler months when growth slows | Mildly toxic to pets |
| Masterwort 'Venice' | Medium indirect light (a couple of metres from a window) | Every 5-7 days; do not allow soil to dry out during active growth | Mildly toxic to pets |
| Matasano | Direct sun (at least 4-6 hours) | Every 2–3 weeks when young; highly drought-tolerant once established | Toxic to pets |
| Mathilde's Rock Jasmine | Direct sun (at least 4-6 hours) | Sparingly; allow to nearly dry between waterings | Mildly toxic to pets |
| Matted Globularia | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; minimal in winter — avoid wetting the crown. | Mildly toxic to pets |
| Matthiola incana 'Giant Imperial Mix' | Direct sun (at least 4-6 hours) | Keep evenly moist; water every 3-5 days, adjusting to weather | Pet-safe |
| Matthiola incana 'Katz Sakura' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water every 3-5 days, more in heat | Pet-safe |
| Maughan's Cone Plant | Direct sun (at least 4-6 hours) | Every 2–4 weeks in autumn growth phase; none during summer dormancy | Pet-safe |
| Maughan's Cone Plant | Direct sun (at least 4-6 hours) | Every 3–4 weeks during the autumn–winter–spring growing period; none from June to late August | Pet-safe |
| Mauritius Lychee | Direct sun (at least 4-6 hours) | 2–3 times per week in summer; withhold supplemental water in winter dry period | Mildly toxic to pets |
| Maury's Air Plant | Direct sun (at least 4-6 hours) | Mist or soak every 10–14 days | Pet-safe |
| Mayapple | Low light (north window or shaded room) | 1–2 times per week during spring; reduce as plant enters summer dormancy | Toxic to pets |
| McDowell's Thelocactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 14-21 days in summer; once a month or less in winter. | Pet-safe |
| Meadow Blazing Star | Direct sun (at least 4-6 hours) | Keep evenly moist to medium; water during dry spells | Pet-safe |
| Meadow Clary | Direct sun (at least 4-6 hours) | Low to moderate; water when the top 5 cm is dry | Mildly toxic to pets |
| meadow fountain grass | Direct sun (at least 4-6 hours) | Weekly when new; every 2–3 weeks once established | Pet-safe |
| Meadow Phlox | Direct sun (at least 4-6 hours) | 1-2 times per week; prefers consistently moist soil | Mildly toxic to pets |
| Meadow Saxifrage | Bright indirect light (just back from a sunny window) | Every 5–7 days in spring; minimal watering needed from midsummer onward | Pet-safe |
| Mediterranean Fan Palm | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Mediterranean feather grass | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; minimal in winter | Pet-safe |
| Mejia's Masdevallia | Medium indirect light (a couple of metres from a window) | Water when the medium is approaching dryness, roughly every 1-2 days in active growth | Pet-safe |
| Membrane-flowered Stelis | Medium indirect light (a couple of metres from a window) | Every 1–2 days; never allow roots to fully dry | Pet-safe |
| Mendoza Graptopetalum | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 10-14 days in summer | Pet-safe |
| Menyanthes trifoliata | Direct sun (at least 4-6 hours) | Keep permanently in wet mud or shallow water; never let it dry | Mildly toxic to pets |
| Merola's Dioon | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; monthly or less in winter | Toxic to pets |
| Mexican Blue Palm | Direct sun (at least 4-6 hours) | Occasional deep soakings; highly drought-tolerant once established | Mildly toxic to pets |
| Mexican Blue Palm | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in summer; reduce to every 3-4 weeks in winter | Pet-safe |
| Mexican Bush Sage | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 2–3 weeks in autumn | Mildly toxic to pets |
| Mexican Butterwort | Bright indirect light (just back from a sunny window) | Tray-water in summer; near-dry in winter | Mildly toxic to pets |
| Mexican Cypress | Direct sun (at least 4-6 hours) | Weekly during establishment; fortnightly in dry periods once mature | Mildly toxic to pets |
| Mexican Feather Grass | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought | Mildly toxic to pets |
| Mexican Fence Post Cactus | Direct sun (at least 4-6 hours) | When the top half of soil is dry, roughly every 10-14 days in summer; every 4-6 weeks in winter | Pet-safe |
| Mexican Fleabane | Direct sun (at least 4-6 hours) | Every 10–14 days during active growth; minimal once established | Pet-safe |
| Mexican Giant Cardon | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 2-3 weeks in summer; minimal in winter | Mildly toxic to pets |
| Mexican Lime Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and every 4-6 weeks in winter | Pet-safe |
| Mexican Pincushion | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days in summer and once a month or less in winter | Pet-safe |
| Mexican Sage | Direct sun (at least 4-6 hours) | Weekly during active growth | Pet-safe |
| Mexican Tree Fern | Bright indirect light (just back from a sunny window) | 2-3 times per week; keep trunk moist | Pet-safe |
| Meyer's Cape Primrose | Bright indirect light (just back from a sunny window) | Every 10-14 days in growth; every 4-6 weeks in winter | Pet-safe |
| Meyer's Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks from late summer (August/September) through autumn; withheld completely from May to August | Pet-safe |
| Michaelovsky Fritillary | Direct sun (at least 4-6 hours) | Moderate during active growth in spring; withhold almost completely from midsummer through autumn | Toxic to pets |
| Middendorf Weigela | Bright indirect light (just back from a sunny window) | Every 7 days during dry periods; keep evenly moist but not waterlogged | Pet-safe |
| Mignonette | Direct sun (at least 4-6 hours) | Every 5–7 days; do not allow to dry out completely | Pet-safe |
| Milkflower cotoneaster | Direct sun (at least 4-6 hours) | Weekly during the first growing season; drought-tolerant once established | Mildly toxic to pets |
| Milky bellflower | Direct sun (at least 4-6 hours) | Weekly during dry periods; moderate water requirements | Pet-safe |
| Milky Way Kousa Dogwood | Bright indirect light (just back from a sunny window) | Weekly while establishing; deep watering in summer drought | Pet-safe |
| Miller's Laelia | Direct sun (at least 4-6 hours) | Every 3–5 days in summer; very sparse in winter (monthly or less) | Pet-safe |
| Million bells | Direct sun (at least 4-6 hours) | Daily in hot weather for containers; every 2–3 days in cooler periods | Mildly toxic to pets |
| Mimulus ringens | Direct sun (at least 4-6 hours) | Keep wet at all times; never allow the soil to dry | Mildly toxic to pets |
| Min Fir | Direct sun (at least 4-6 hours) | Regularly during establishment; moderate thereafter | Pet-safe |
| Miniature Chusan Palm | Bright indirect light (just back from a sunny window) | Weekly in the growing season, reduced in winter | Pet-safe |
| Miniature Cone Plant | Bright indirect light (just back from a sunny window) | Every 10–14 days during active growth (autumn–spring); completely dry through summer dormancy | Pet-safe |
| Miniature Cone Plant | Direct sun (at least 4-6 hours) | Strictly seasonal: water very sparingly from September to early April; completely dry from April through August | Mildly toxic to pets |
| Minnesota Trout Lily | Medium indirect light (a couple of metres from a window) | Moist throughout active growth (April–May); bone-dry conditions are fatal | Mildly toxic to pets |
| Minor Sun Pitcher | Bright indirect light (just back from a sunny window) | Water every 3-5 days to keep the substrate consistently moist; maintain partial pitcher fill with distilled water | Pet-safe |
| Mintleaf Spurflower | Bright indirect light (just back from a sunny window) | Every 7-10 days, allowing the top 2-3 cm of soil to dry between waterings | Mildly toxic to pets |
| Miquel's Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks | Toxic to pets |
| Miss Grace Dawn Redwood | Direct sun (at least 4-6 hours) | Weekly or more in dry periods; tolerates wet soils | Pet-safe |
| Miss Jekyll love-in-a-mist | Direct sun (at least 4-6 hours) | Weekly or as needed | Mildly toxic to pets |
| Miss Kim Lilac | Direct sun (at least 4-6 hours) | Weekly to establish, then occasional deep watering in drought | Mildly toxic to pets |
| Miss Sharples Maidenhair Fern | Medium indirect light (a couple of metres from a window) | Every 4–6 days; maintain consistent soil moisture | Pet-safe |
| Miss Wilmott's Ghost | Direct sun (at least 4-6 hours) | Water occasionally in the first year, then rarely once established | Mildly toxic to pets |
| Missouri Foxtail Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, roughly every 10-21 days in summer; virtually none in winter | Pet-safe |
| Mitchell's Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method, seasonally adjusted | Pet-safe |
| Mitla Air Plant | Direct sun (at least 4-6 hours) | Water 1–3 times per week depending on season | Pet-safe |
| Mock Orange | Direct sun (at least 4-6 hours) | Water in dry spells; drought-tolerant once established | Mildly toxic to pets |
| Mock Orange 'Belle Etoile' | Direct sun (at least 4-6 hours) | Weekly while establishing; during dry spells thereafter | Mildly toxic to pets |
| Moctezuma Butterwort | Bright indirect light (just back from a sunny window) | Tray-water in summer; near-dry in winter | Mildly toxic to pets |
| Modoc Cypress | Direct sun (at least 4-6 hours) | Minimal once established; drought-tolerant | Pet-safe |
| Moluccan Fishtail Palm | Direct sun (at least 4-6 hours) | Regularly; maintain consistent soil moisture | Mildly toxic to pets |
| Momi Fir | Direct sun (at least 4-6 hours) | Moderate; water regularly during establishment | Pet-safe |
| Monarch Birch | Direct sun (at least 4-6 hours) | Regular watering for first 2–3 years; moderate once established | Pet-safe |
| Monarch of the East | Bright indirect light (just back from a sunny window) | Minimal until potted and in growth; then water when the top 2-3 cm of soil is dry | Toxic to pets |
| Monarch of the Veldt | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Mildly toxic to pets |
| Monarda 'Jacob Cline' | Direct sun (at least 4-6 hours) | Water deeply about once or twice a week, keeping soil consistently moist | Mildly toxic to pets |
| Monarda 'Marshall's Delight' | Direct sun (at least 4-6 hours) | Water deeply once or twice a week to keep soil evenly moist | Mildly toxic to pets |
| Monk's Hood Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 10-14 days in summer; every 4-6 weeks or less in winter | Pet-safe |
| Monkey flower | Medium indirect light (a couple of metres from a window) | Every 2–3 days; more frequently in warm or windy weather | Pet-safe |
| Monster Scaphosepalum | Medium indirect light (a couple of metres from a window) | When the top of the medium just begins to dry, roughly every 3-5 days | Pet-safe |
| Monstrose Apple Cactus | Direct sun (at least 4-6 hours) | When the mix is dry, roughly every 10-14 days in summer; minimal in winter | Pet-safe |
| Mont Cenis Bellflower | Direct sun (at least 4-6 hours) | Very low — water sparingly during growth; keep dry in winter | Mildly toxic to pets |
| Montbretia 'Lucifer' | Direct sun (at least 4-6 hours) | Approximately every 7-10 days during the growing season; reduce to monthly once dormant in autumn | Mildly toxic to pets |
| Monterey Cypress | Direct sun (at least 4-6 hours) | Weekly during establishment; infrequent once mature | Mildly toxic to pets |
| Montezuma Cypress | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water deeply every 7-14 days, more frequently in heat | Pet-safe |
| Montgomery Astilbe | Bright indirect light (just back from a sunny window) | Keep soil consistently moist to wet; water when the top 2-3 cm dries, roughly every 3-5 days in summer | Mildly toxic to pets |
| Montpellier Rock Rose | Direct sun (at least 4-6 hours) | Low — establishment watering only | Mildly toxic to pets |
| Moon Cactus | Bright indirect light (just back from a sunny window) | Every 14–21 days in spring/summer; every 4–6 weeks in autumn; almost none in winter | Pet-safe |
| Moonglow Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days when establishing, then deep occasional soaks | Mildly toxic to pets |
| Moonshadow Euonymus | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Moor Witch Purple Moor Grass | Bright indirect light (just back from a sunny window) | Moderate to frequent — prefers reliably moist soil; dislikes drought | Pet-safe |
| Moorcroft's Sage | Direct sun (at least 4-6 hours) | Moderate during growth; minimal in winter | Pet-safe |
| Moore's Coelogyne | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 10–14 days in winter | Pet-safe |
| Moore's Coelogyne | Bright indirect light (just back from a sunny window) | Every 5-7 days in the growing season; every 14-21 days in winter | Pet-safe |
| Moore's Crinum | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in the growing season | Toxic to pets |
| Moore's Cycad | Bright indirect light (just back from a sunny window) | Water every 2–4 weeks during active growth, sparingly in winter | Toxic to pets |
| Moore's Macrozamia | Bright indirect light (just back from a sunny window) | Every 2–4 weeks | Toxic to pets |
| Mophead Hydrangea 'Cityline Paris' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, often 2-3 times weekly in summer heat | Toxic to pets |
| Moretti's Bellflower | Bright indirect light (just back from a sunny window) | Low to moderate — water carefully during growth, keep dry in winter | Mildly toxic to pets |
| Morning Light Maiden Grass | Direct sun (at least 4-6 hours) | Weekly while establishing in the first year, then only during prolonged drought | Mildly toxic to pets |
| Morning Light Maiden Grass | Direct sun (at least 4-6 hours) | Weekly for the first growing season; every 2–3 weeks once established | Pet-safe |
| Moroccan toadflax | Direct sun (at least 4-6 hours) | Once or twice a week; reduce to weekly once established | Mildly toxic to pets |
| Moser's Gymnocalycium | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, approximately every 7-10 days in summer; every 4-6 weeks in winter | Pet-safe |
| Moso Bamboo | Direct sun (at least 4-6 hours) | 2–3 times per week in the growing season; weekly in winter | Pet-safe |
| Mossy Saxifrage | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth; reduce in summer heat and winter | Pet-safe |
| Moth Mullein | Direct sun (at least 4-6 hours) | Every 10–14 days during dry spells; largely self-sufficient once established | Mildly toxic to pets |
| Mother of Hundreds | Direct sun (at least 4-6 hours) | Every 10-14 days in spring-summer when the top 3 cm of soil is dry; every 4-6 weeks in autumn and winter | Pet-safe |
| Mother of Pearl poppy | Direct sun (at least 4-6 hours) | Once or twice weekly during establishment; minimal once established | Mildly toxic to pets |
| Mother of Thousands | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days in summer | Toxic to pets |
| Mottled Wild Ginger | Low light (north window or shaded room) | Every 7–10 days during the growing season; every 14 days once well established | Mildly toxic to pets |
| Moudry Black Fountain Grass | Direct sun (at least 4-6 hours) | Weekly during establishment, then occasional deep watering in dry spells | Pet-safe |
| Mount Etna Broom | Direct sun (at least 4-6 hours) | Low — very drought-tolerant once established | Toxic to pets |
| Mountain African Daisy | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season | Mildly toxic to pets |
| Mountain Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, every 1-3 weeks in warm growth | Toxic to pets |
| Mountain Alyssum | Direct sun (at least 4-6 hours) | Every 14–21 days during growth; minimal in winter | Pet-safe |
| Mountain Bellwort | Medium indirect light (a couple of metres from a window) | Once per week during the growing season; less frequent than other bellworts owing to this species' preference for drier conditions. | Mildly toxic to pets |
| Mountain Bladder Fern | Low light (north window or shaded room) | 2-3 times per week in active growth; reduce when dormant | Pet-safe |
| Mountain Bluebells | Bright indirect light (just back from a sunny window) | Water deeply 2–3 times per week; does not tolerate drying out | Pet-safe |
| Mountain Cornflower | Direct sun (at least 4-6 hours) | Weekly in the first season; established plants are drought-tolerant and rarely need watering | Pet-safe |
| Mountain Desert Sage | Direct sun (at least 4-6 hours) | Very low once established; xeric to moderate | Pet-safe |
| Mountain Fern | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water when the top 2-3 cm dry out, roughly weekly in dry weather | Mildly toxic to pets |
| Mountain Fetterbush | Bright indirect light (just back from a sunny window) | Water every 7–14 days; once established it is relatively drought-tolerant for a Pieris | Toxic to pets |
| Mountain Fire pieris | Bright indirect light (just back from a sunny window) | Weekly to bi-weekly depending on conditions | Toxic to pets |
| Mountain Germander | Direct sun (at least 4-6 hours) | Rarely once established; water during dry spells in the first season | Mildly toxic to pets |
| Mountain Hemlock | Direct sun (at least 4-6 hours) | Weekly during establishment; relies on rainfall and snowmelt once established | Pet-safe |
| Mountain Hydrangea 'Bluebird' | Bright indirect light (just back from a sunny window) | About weekly, roughly 2.5 cm (1 inch) per week; water when the top 3-5 cm of soil is dry | Toxic to pets |
| mountain laurel | Bright indirect light (just back from a sunny window) | Weekly during establishment; water during dry spells once established | Toxic to pets |
| Mountain Laurel 'Olympic Fire' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry; keep evenly moist, especially in the first years | Toxic to pets |
| Mountain Pieris | Bright indirect light (just back from a sunny window) | Keep evenly moist; water weekly in dry weather and never allow drought stress | Toxic to pets |
| Mountain Pine | Direct sun (at least 4-6 hours) | When the soil surface starts to dry, then soak thoroughly | Mildly toxic to pets |
| Mountain Rimu | Bright indirect light (just back from a sunny window) | Every 7-14 days; keep soil consistently moist, especially in summer | Mildly toxic to pets |
| Mountain Strelitzia | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 7-14 days in summer | Mildly toxic to pets |
| Mountain Sweet Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method, moist year-round | Pet-safe |
| Mourning Holly Fern | Low light (north window or shaded room) | Every 5–7 days in the growing season, every 10–14 days in winter | Pet-safe |
| Mouse Head Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks year-round, with a brief reduction after flowering | Mildly toxic to pets |
| Mouse-ear Hawkweed | Direct sun (at least 4-6 hours) | Infrequent — allow soil to dry between waterings | Mildly toxic to pets |
| Mouse-Tail Air Plant | Bright indirect light (just back from a sunny window) | Mist or soak every 10–14 days | Pet-safe |
| Mpumalanga Cycad | Direct sun (at least 4-6 hours) | Every 3–5 weeks | Toxic to pets |
| Mr Bowling Ball Arborvitae | Direct sun (at least 4-6 hours) | Twice weekly while establishing; weekly thereafter | Mildly toxic to pets |
| Mugo Pine | Direct sun (at least 4-6 hours) | Water weekly while establishing the first year, then only in prolonged drought | Mildly toxic to pets |
| Muir's Living Pebble | Direct sun (at least 4-6 hours) | Only when the body begins to slightly wrinkle, roughly every 3-4 weeks during the autumn-spring growing season; completely dry through summer dormancy | Mildly toxic to pets |
| Muir's Rhinephyllum | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring–summer; minimal in winter | Pet-safe |
| Muir's Rhinephyllum | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 21-28 days in the growing season (autumn-spring); almost none in summer | Mildly toxic to pets |
| Muir's Sage | Direct sun (at least 4-6 hours) | Low; drought tolerant once established | Pet-safe |
| Mulanje Cycad | Direct sun (at least 4-6 hours) | Weekly to fortnightly in summer; every 3–4 weeks in winter | Toxic to pets |
| Mulberry Wine prickly heath | Bright indirect light (just back from a sunny window) | Regular; keep consistently moist | Toxic to pets |
| Munby's Rock Rose | Direct sun (at least 4-6 hours) | Very low — drought-tolerant once established | Mildly toxic to pets |
| Muscari 'White Magic' | Direct sun (at least 4-6 hours) | Rainfall in most settings; water in dry spring spells | Pet-safe |
| Muscari armeniacum | Direct sun (at least 4-6 hours) | Rainfall in most settings; water in dry spring spells | Pet-safe |
| Musk Mallow | Direct sun (at least 4-6 hours) | Low to moderate once established | Pet-safe |
| Mutton Bird Sedge | Bright indirect light (just back from a sunny window) | Moderate to regular; do not allow to dry out in the growing season | Pet-safe |
| Myretoun Ruby winter heath | Direct sun (at least 4-6 hours) | Weekly for new plants in the first season; every 2–3 weeks for established plants during dry spells | Pet-safe |
| Myriophyllum spicatum | Direct sun (at least 4-6 hours) | Continuously submerged; maintain pond level so plants sit in 0.5-3 m of water | Mildly toxic to pets |
| Myrtillocactus geometrizans | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 1-2 weeks in summer; sparingly in winter | Mildly toxic to pets |
| Nahanni Fern | Bright indirect light (just back from a sunny window) | Keep evenly moist; water when the top 2 cm of soil begins to dry, roughly weekly in dry spells | Mildly toxic to pets |
| Naked Bamboo | Medium indirect light (a couple of metres from a window) | 2-3 times per week in growing season; reduce in winter | Pet-safe |
| Naked Crocus | Bright indirect light (just back from a sunny window) | Low to moderate — prefers moisture during active growth; dry in summer | Mildly toxic to pets |
| Namaqualand Cheiridopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks during autumn through early spring; completely dry June–August | Pet-safe |
| Namaqualand Sage | Direct sun (at least 4-6 hours) | Low; sparingly once established | Pet-safe |
| Nana Lutea Hinoki Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days while establishing, then when the top few cm of soil dry | Mildly toxic to pets |
| Nananthus transvaalensis | Direct sun (at least 4-6 hours) | Only when soil is bone dry, about every 10-14 days in growth; minimal in summer and winter dormancy | Mildly toxic to pets |
| Nandina Firepower | Direct sun (at least 4-6 hours) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Nandina Gulf Stream | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 10-14 days in dry spells | Toxic to pets |
| Nandina Harbour Dwarf | Bright indirect light (just back from a sunny window) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Nandina Obsessed | Direct sun (at least 4-6 hours) | Weekly while establishing, then every 10-14 days once mature | Toxic to pets |
| Nannorrhops Ritchiana | Direct sun (at least 4-6 hours) | When soil has dried out, roughly every 10-21 days in heat | Mildly toxic to pets |
| nannyberry | Bright indirect light (just back from a sunny window) | Weekly for first two seasons; infrequently once established | Mildly toxic to pets |
| Naomi Hakone Grass | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Narcissus 'February Gold' | Direct sun (at least 4-6 hours) | Moist during autumn-to-spring growth; dry through summer dormancy | Toxic to pets |
| Narcissus 'Hawera' | Direct sun (at least 4-6 hours) | Keep soil evenly moist during active growth (autumn rooting through spring flowering); largely dry in summer dormancy | Toxic to pets |
| Narcissus 'Ice Follies' | Direct sun (at least 4-6 hours) | Moist in spring growth; drier through summer dormancy | Toxic to pets |
| Narcissus 'Jetfire' | Direct sun (at least 4-6 hours) | Moist during spring growth; drier through summer dormancy | Toxic to pets |
| Narcissus 'Minnow' | Direct sun (at least 4-6 hours) | Evenly moist while in leaf and flower; dry in summer dormancy | Toxic to pets |
| Narcissus 'Pipit' | Direct sun (at least 4-6 hours) | Moist in spring growth; drier through summer dormancy | Toxic to pets |
| Narcissus 'Tahiti' | Direct sun (at least 4-6 hours) | Moist in spring growth; drier through summer dormancy | Toxic to pets |
| Narcissus 'Tete-a-Tete' | Direct sun (at least 4-6 hours) | Moist in spring growth; drier through summer dormancy | Toxic to pets |
| Narcissus 'Thalia' | Direct sun (at least 4-6 hours) | Moist in spring growth; drier through summer dormancy | Toxic to pets |
| Nardoo | Direct sun (at least 4-6 hours) | Aquatic — grow permanently in shallow water 5–15 cm deep, or in waterlogged pond margin soil | Pet-safe |
| Narrow Holly Fern | Medium indirect light (a couple of metres from a window) | Every 7–14 days; drought-tolerant once established | Pet-safe |
| Narrow Rib Cereus | Direct sun (at least 4-6 hours) | Every 2–4 weeks in growing season; once a month or less in winter | Mildly toxic to pets |
| narrow small-reed | Direct sun (at least 4-6 hours) | Keep constantly moist to wet; suited to boggy, saturated, or seasonally flooded soils | Pet-safe |
| Narrow-Leaf Bird of Paradise | Direct sun (at least 4-6 hours) | Allow soil to dry well between waterings; approximately every 10–21 days in the growing season, very infrequent in winter | Toxic to pets |
| Narrow-Leaf Coneflower | Direct sun (at least 4-6 hours) | Water to establish in year one, then only in prolonged drought | Pet-safe |
| Narrow-leaf Dioon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month in winter | Toxic to pets |
| Narrow-Leaf Fountain Bamboo | Medium indirect light (a couple of metres from a window) | 2-3 times per week in warm months; weekly in cool weather | Pet-safe |
| Narrow-Leaved Ash | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Pet-safe |
| Narrow-leaved Biarum | Direct sun (at least 4-6 hours) | Light watering in autumn–spring active growth; completely dry in summer | Toxic to pets |
| Narrow-Leaved Bird of Paradise | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is completely dry, roughly every 10-14 days in summer | Mildly toxic to pets |
| Narrow-leaved Fockea | Bright indirect light (just back from a sunny window) | Every 10–14 days in growing season; once a month or less in winter | Mildly toxic to pets |
| Narrow-leaved Gentian | Bright indirect light (just back from a sunny window) | Moderate; allow the top centimetre of soil to dry between waterings | Pet-safe |
| Narrow-leaved Glade Fern | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water when the top 2 cm begin to dry, roughly every 5-7 days in dry weather | Mildly toxic to pets |
| Narrow-Leaved Spleenwort | Low light (north window or shaded room) | Every 2–3 days in warm months; reduce in winter | Pet-safe |
| Narrow-leaved Water Plantain | Direct sun (at least 4-6 hours) | Marginal aquatic; submerged 0–20 cm over the crown | Mildly toxic to pets |
| Narrow-leaved Watsonia | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry during active growth, roughly every 7-14 days | Mildly toxic to pets |
| Narrow-Petaled Hechtia | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer | Mildly toxic to pets |
| Narrowleaf gazania | Direct sun (at least 4-6 hours) | Every 10–21 days once established; twice weekly when newly planted | Mildly toxic to pets |
| Narvaez Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Natal Cycad | Direct sun (at least 4-6 hours) | Every 14–21 days (allow soil to dry between waterings) | Toxic to pets |
| Natal Lily | Bright indirect light (just back from a sunny window) | Every 7–10 days in spring and summer; sparingly (every 3–4 weeks) during the winter rest | Toxic to pets |
| Natal Sundew | Direct sun (at least 4-6 hours) | Keep in a shallow tray of 1–2 cm pure water throughout the growing season; allow the tray to dry briefly in winter during dormancy. | Pet-safe |
| Nathalie's Ramonda | Medium indirect light (a couple of metres from a window) | Once or twice a week in the growing season; minimal in winter | Pet-safe |
| Naureen's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during the active autumn-to-spring period; completely dry in summer | Pet-safe |
| Neblina Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep medium consistently moist; flush pitchers with pure water weekly | Pet-safe |
| Needle Grass | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Needle Palm | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, about every 5-7 days while actively growing | Mildly toxic to pets |
| Neglected Air Plant | Bright indirect light (just back from a sunny window) | Soak for 30 minutes to 2 hours once a week | Pet-safe |
| Neglected Pink | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry between waterings | Toxic to pets |
| Nejapa Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer; once every 5-8 weeks in winter | Pet-safe |
| Nel's Tongue Plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; once a month or less in winter | Mildly toxic to pets |
| Neli's Rhombophyllum | Bright indirect light (just back from a sunny window) | Every 3–4 weeks in growing season (autumn–spring); withhold almost entirely in summer | Mildly toxic to pets |
| Neli's Tongue Plant | Bright indirect light (just back from a sunny window) | Every 2–4 weeks in autumn and spring growing seasons; near-dry in summer dormancy and restricted in winter | Mildly toxic to pets |
| Nemesia 'Sunsatia Cranberry' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-3 days in warm weather | Pet-safe |
| Nemesia strumosa 'Poetry Blue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-3 days in warm weather | Pet-safe |
| Neon Tangerine Calendula | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Nepenthes edwardsiana | Bright indirect light (just back from a sunny window) | Keep media constantly moist, watering roughly every 1-2 days | Mildly toxic to pets |
| Nepenthes macrophylla | Bright indirect light (just back from a sunny window) | Keep the mix evenly moist, watering about every 1-3 days | Mildly toxic to pets |
| Nepenthes nebularum | Bright indirect light (just back from a sunny window) | Keep media constantly moist, watering roughly every 1-2 days | Mildly toxic to pets |
| Nepeta 'Six Hills Giant' | Direct sun (at least 4-6 hours) | When soil is dry to a few centimetres; infrequently once established | Mildly toxic to pets |
| Nepeta 'Walker's Low' | Direct sun (at least 4-6 hours) | When the top few centimetres are dry; weekly while establishing | Mildly toxic to pets |
| Nepeta racemosa 'Blue Wonder' | Direct sun (at least 4-6 hours) | When the top few centimetres are dry; weekly while establishing | Mildly toxic to pets |
| Nepeta sibirica 'Souvenir d'André Chaudron' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry; sparingly once established | Mildly toxic to pets |
| Nest Air Plant | Bright indirect light (just back from a sunny window) | Mist or dip 2–3 times per week in summer; once per week in cool winter conditions. | Pet-safe |
| Net-scaled Ceratostylis | Bright indirect light (just back from a sunny window) | When the upper surface of the medium is just drying, roughly every 4-6 days | Pet-safe |
| Netted Chain Fern | Low light (north window or shaded room) | Freely — keep soil moist to seasonally wet | Pet-safe |
| Nettle-leaved Mullein | Direct sun (at least 4-6 hours) | Every 10–14 days during dry spells; seldom needed once established | Mildly toxic to pets |
| Nevada Bitterroot | Direct sun (at least 4-6 hours) | Moderate in spring; completely dry in summer dormancy | Pet-safe |
| Nevada Lewisia | Bright indirect light (just back from a sunny window) | Moderate in spring; almost none in summer dormancy | Mildly toxic to pets |
| New Dawn Rose | Direct sun (at least 4-6 hours) | Deeply once a week in the growing season; more during establishment or drought | Pet-safe |
| New England Aster | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water weekly, more in heat | Pet-safe |
| New England Aster 'Purple Dome' | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply during dry spells, about weekly | Pet-safe |
| New England Aster 'Purple Dome' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7 days in summer | Mildly toxic to pets |
| New York aster | Direct sun (at least 4-6 hours) | Weekly during the growing season; less frequent once established in cool climates | Pet-safe |
| New York Aster 'Fellowship' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| New York Fern | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water when the top 2-3 cm begin to dry, roughly weekly in dry spells | Mildly toxic to pets |
| New York Ironweed | Direct sun (at least 4-6 hours) | Keep consistently moist; water weekly when rainfall is short | Mildly toxic to pets |
| New Zealand Gentian | Bright indirect light (just back from a sunny window) | Keep moist but never waterlogged; reduce in winter | Mildly toxic to pets |
| New Zealand Tree Fern | Bright indirect light (just back from a sunny window) | Consistently moist — water 2-3 times per week during dry spells in the growing season | Pet-safe |
| New Zealand Tree Fuchsia | Bright indirect light (just back from a sunny window) | Regular — consistent moisture | Pet-safe |
| Nicholas Hakone Grass | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water 1-2 times weekly, more in heat | Mildly toxic to pets |
| Night Sky Petunia | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of compost feels dry, typically every 2-4 days in warm weather; containers may need daily watering in midsummer heat | Pet-safe |
| Night-blooming Jasmine | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth; reduce to every 10–14 days in cooler months | Toxic to pets |
| Night-scented stock | Direct sun (at least 4-6 hours) | Every 7–10 days; allow soil to dry between waterings | Pet-safe |
| Nikko Fir | Direct sun (at least 4-6 hours) | Weekly when establishing; reduced once established | Pet-safe |
| Nile Sage | Bright indirect light (just back from a sunny window) | Moderate; consistent moisture preferred | Pet-safe |
| Ninebark 'Diabolo' | Direct sun (at least 4-6 hours) | Weekly while establishing; established plants only in prolonged drought | Mildly toxic to pets |
| Ninja Foamflower | Medium indirect light (a couple of metres from a window) | Every 5–7 days; increase in warm or dry periods | Pet-safe |
| Ninja Tiarella | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water deeply once or twice a week during dry periods | Mildly toxic to pets |
| Nivalis flowering quince | Bright indirect light (just back from a sunny window) | Weekly during establishment; rainfall usually sufficient once established | Mildly toxic to pets |
| Nobile Dendrobium | Bright indirect light (just back from a sunny window) | Frequently in spring-summer growth, then sharply reduced over the cool winter rest | Pet-safe |
| Noble Carrion Flower | Bright indirect light (just back from a sunny window) | Every 14–21 days in the growing season; once monthly or less in winter | Pet-safe |
| Noble Cymbidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; every 10–14 days in winter | Pet-safe |
| Noble Cymbidium | Bright indirect light (just back from a sunny window) | Keep lightly and evenly moist, about every 5-7 days, reduced in winter | Pet-safe |
| Noble Dendrobium (miniature form) | Bright indirect light (just back from a sunny window) | Every 5-7 days in summer; every 14-21 days in the winter rest period | Pet-safe |
| Noble Fir | Direct sun (at least 4-6 hours) | Regular watering during establishment; naturally sustained by Pacific Northwest rainfall | Pet-safe |
| Nodding Enkianthus | Bright indirect light (just back from a sunny window) | Regularly; maintain even soil moisture | Mildly toxic to pets |
| Nodding Greenhood | Medium indirect light (a couple of metres from a window) | Lightly moist during active growth (autumn–spring), roughly every 5-8 days | Pet-safe |
| Nodding Sage | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to dry between waterings | Pet-safe |
| Nodding Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep substrate moist at all times; shallow tray or top-watering | Mildly toxic to pets |
| Nodding Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist to seasonally wet; tolerates more moisture than most Trilliums. | Mildly toxic to pets |
| Nodding Wand Flower | Direct sun (at least 4-6 hours) | Heavy from early spring to late summer; reduced in autumn and winter | Mildly toxic to pets |
| Nootka Cypress | Direct sun (at least 4-6 hours) | Regularly during establishment; tolerates wet or dry once mature | Pet-safe |
| Nootka Lupin | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days once established | Toxic to pets |
| Nordmann Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; relies on rainfall once established | Pet-safe |
| Norfolk Island Spleenwort | Medium indirect light (a couple of metres from a window) | Every 5–7 days; adjust seasonally | Pet-safe |
| Northern Holly Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days; less in winter | Pet-safe |
| Northern Japanese Hemlock | Bright indirect light (just back from a sunny window) | Weekly during growing season; less in winter | Pet-safe |
| Northern Needleleaf Air Plant | Bright indirect light (just back from a sunny window) | Soak once a week; mist every 2–3 days | Pet-safe |
| Northern Red Oak | Direct sun (at least 4-6 hours) | Regular deep watering in the first 2-3 years; established trees are moderately drought-tolerant | Mildly toxic to pets |
| Northern Sea Oats | Bright indirect light (just back from a sunny window) | Water to keep soil moist, deeply once or twice weekly in dry periods | Mildly toxic to pets |
| Northwind Switch Grass | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water deeply every 1-2 weeks while young | Mildly toxic to pets |
| Norway Maple | Direct sun (at least 4-6 hours) | Deeply every 7-14 days during the first three growing seasons; established mature trees are largely self-sufficient but benefit from watering during severe drought | Mildly toxic to pets |
| Norway Spruce | Direct sun (at least 4-6 hours) | When the top centimetre of soil begins to dry, often daily in summer | Mildly toxic to pets |
| Notable Slipper Orchid | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of the medium is dry, approximately every 5-7 days; reduce slightly in winter | Mildly toxic to pets |
| Notched Butterwort | Medium indirect light (a couple of metres from a window) | Keep consistently moist; reduce slightly in cooler months | Mildly toxic to pets |
| Nottingham Catchfly | Bright indirect light (just back from a sunny window) | Low; allow soil to dry between waterings | Mildly toxic to pets |
| Novak's Air Plant | Bright indirect light (just back from a sunny window) | Mist thoroughly 2–3 times per week in warm conditions; reduce to once per week in cool, low-humidity winters. | Pet-safe |
| Nude Sheath Bamboo | Direct sun (at least 4-6 hours) | Weekly during the growing season; every 2–3 weeks when dormant | Pet-safe |
| Nuphar lutea | Direct sun (at least 4-6 hours) | Permanently submerged roots; keep crown in 0.3-2.5 m of water | Mildly toxic to pets |
| Nuphar polysepala | Direct sun (at least 4-6 hours) | Permanently submerged roots; keep crown in 0.3-2 m of water | Mildly toxic to pets |
| Nuttall's Waterweed | Medium indirect light (a couple of metres from a window) | Permanently submerged | Pet-safe |
| Nyssa sylvatica | Direct sun (at least 4-6 hours) | Weekly while establishing; keep soil moist to wet | Mildly toxic to pets |
| Oak Fern | Bright indirect light (just back from a sunny window) | Keep evenly moist; water when the top 2 cm begins to dry, roughly weekly in dry weather | Mildly toxic to pets |
| Oak-leaf Primulina | Medium indirect light (a couple of metres from a window) | Allow soil to become fairly dry between waterings | Mildly toxic to pets |
| Oakleaf Hydrangea | Bright indirect light (just back from a sunny window) | Keep soil moist while establishing; then water deeply during dry spells, roughly weekly in summer heat | Toxic to pets |
| Oakleaf Hydrangea 'Snow Queen' | Bright indirect light (just back from a sunny window) | Roughly weekly, about 2.5 cm (1 inch) per week while establishing; deep-soak when the top 5 cm of soil dries | Toxic to pets |
| Oaxacan Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week or soak for 20–30 minutes once per week; reduce in cooler months. | Pet-safe |
| Ochre Coelogyne | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce to once every 2–3 weeks in winter rest | Pet-safe |
| Ocotillo | Direct sun (at least 4-6 hours) | Rainfall-dependent; irrigate every 3–4 weeks in summer heat; minimal to none in cool months | Mildly toxic to pets |
| October Daphne | Bright indirect light (just back from a sunny window) | Every 10-14 days in active growth; minimal in winter dormancy | Pet-safe |
| Odontoglossum crispum | Bright indirect light (just back from a sunny window) | Keep evenly moist year-round, watering roughly every 3-5 days so the mix never fully dries | Pet-safe |
| Ogon Sweet Flag | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water whenever the surface begins to feel barely damp | Mildly toxic to pets |
| Old Father Live Forever | Bright indirect light (just back from a sunny window) | Water when the top 3–5 cm of compost is dry, roughly every 10–14 days; reduce in winter | Toxic to pets |
| Old Gold Juniper | Direct sun (at least 4-6 hours) | Water regularly the first season; afterward only during sustained drought | Toxic to pets |
| Old Lady Pincushion | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Old Man Eriosyce | Direct sun (at least 4-6 hours) | When the potting mix has dried out completely, roughly every 14-21 days in the growing season | Pet-safe |
| Old Man of the Andes | Direct sun (at least 4-6 hours) | When the soil has dried out, about every 2 weeks in summer; very sparingly in winter | Mildly toxic to pets |
| Old Man Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 6-8 weeks in winter | Pet-safe |
| Old Woman Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, every 10-14 days in summer | Pet-safe |
| old-fashioned weigela | Direct sun (at least 4-6 hours) | Weekly during the first growing season; once or twice per month during dry spells when established | Pet-safe |
| Oleander | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days once established | Toxic to pets |
| Olive Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during active growth (autumn to early spring); none in summer | Pet-safe |
| Olive Living Stones | Direct sun (at least 4-6 hours) | Seasonally — autumn watering only (September–November); completely dry during winter and summer dormancy | Pet-safe |
| Olive Porroglossum | Medium indirect light (a couple of metres from a window) | Water or mist daily in warm months; every 1-2 days in cooler months — roots must never fully dry out | Pet-safe |
| Oliver's impatiens | Medium indirect light (a couple of metres from a window) | Every 4–7 days; moderate and consistent | Pet-safe |
| Olympic Mullein | Direct sun (at least 4-6 hours) | Every 14–21 days; very drought-tolerant once established | Mildly toxic to pets |
| Olympic St. John's Wort | Direct sun (at least 4-6 hours) | Every 10–14 days; drought-tolerant once established | Toxic to pets |
| One-flower Masdevallia | Medium indirect light (a couple of metres from a window) | When the top 1 cm of moss or mix begins to dry, approximately every 3-5 days; never allow to dry out completely | Pet-safe |
| One-flowered Clintonia | Low light (north window or shaded room) | Maintain consistently moist soil; water deeply when the top 2 cm begins to dry | Mildly toxic to pets |
| Ophir Mugo Pine | Direct sun (at least 4-6 hours) | Water weekly during the first growing season, then only in extended drought | Mildly toxic to pets |
| Opium poppy | Direct sun (at least 4-6 hours) | Weekly during establishment; every 10–14 days once growing strongly | Toxic to pets |
| Opposite-Flowered Sage | Direct sun (at least 4-6 hours) | Moderate; allow the top few centimetres of soil to dry between waterings | Mildly toxic to pets |
| Opposite-leaf Cliff Stonecrop | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; very rarely in winter | Pet-safe |
| Optic Living Stones | Direct sun (at least 4-6 hours) | Strictly seasonal: water sparingly during active growth (late summer to spring); completely dry in summer dormancy (June–August) | Pet-safe |
| Optical Plant | Direct sun (at least 4-6 hours) | Seasonally — water only during autumn active growth (September–November); completely dry rest of year | Pet-safe |
| Orache-Leaved Sun Rose | Direct sun (at least 4-6 hours) | Very low — once every 3–4 weeks in summer; rely on rainfall in other seasons | Mildly toxic to pets |
| Orange Glow Firethorn | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Orange Lily | Direct sun (at least 4-6 hours) | When top 2–3 cm of soil is dry | Toxic to pets |
| Orange Prosthechea | Bright indirect light (just back from a sunny window) | When the top layer of the mix is dry, roughly every 6-9 days; reduce slightly in winter | Pet-safe |
| Orange Queen Epimedium | Medium indirect light (a couple of metres from a window) | Weekly during establishment and dry spells; established clumps are notably drought-tolerant | Mildly toxic to pets |
| Orange River Climbing Onion | Bright indirect light (just back from a sunny window) | Every 1–2 weeks during active vine growth; completely dry during summer dormancy | Toxic to pets |
| Orange River Lily | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days during the growing season | Toxic to pets |
| Orange Sneezeweed | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Orange Snow Ball Cactus | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil is dry, roughly every 7-10 days in spring and summer; every 4-6 weeks in autumn; none or barely any in winter | Pet-safe |
| Orange Star | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days during active growth | Toxic to pets |
| Orange Stonecrop | Direct sun (at least 4-6 hours) | Every 10-14 days when establishing; virtually rain-fed once mature | Pet-safe |
| Orange Woolly Sage | Bright indirect light (just back from a sunny window) | Weekly in the growing season; reduce to monthly in winter | Pet-safe |
| Orange-Flowered Matucana | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in summer | Pet-safe |
| Orcutt's Liveforever | Direct sun (at least 4-6 hours) | Every 1–2 weeks in autumn through spring (growing season); withhold almost entirely in summer | Pet-safe |
| Oregon Stonecrop | Bright indirect light (just back from a sunny window) | Every 10-14 days in active growth; monthly or less in winter | Pet-safe |
| Oreocharis auricula | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil is dry, roughly every 4-6 days in growth | Mildly toxic to pets |
| Oriental Chain Fern | Medium indirect light (a couple of metres from a window) | Regularly — keep soil consistently moist | Pet-safe |
| Oriental Ostrich Fern | Low light (north window or shaded room) | Regularly — keep soil consistently moist to moderately dry | Pet-safe |
| Oriental Sweetgum | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once established | Mildly toxic to pets |
| Ornamental Plum 'Nigra' | Direct sun (at least 4-6 hours) | Weekly while establishing; little once mature | Toxic to pets |
| Orpen's Aloinopsis | Bright indirect light (just back from a sunny window) | Every 10–14 days in autumn–spring; minimal in summer | Pet-safe |
| Orpen's Aloinopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks during autumn through early spring; once a month or not at all through summer | Pet-safe |
| Orpheus Flower | Medium indirect light (a couple of metres from a window) | Lightly and consistently, keeping the root zone barely moist but never wet | Mildly toxic to pets |
| Orpine | Direct sun (at least 4-6 hours) | Every 1–2 weeks during dry spells; drought-tolerant once established | Mildly toxic to pets |
| Orssich's Holiday Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season; reduce to every 2-3 weeks during the autumn rest | Pet-safe |
| Osbeck's Rock Rose | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Osmunda regalis 'Purpurascens' | Medium indirect light (a couple of metres from a window) | Keep soil constantly moist to wet; check every 2-3 days in growth | Mildly toxic to pets |
| Osmunda spectabilis | Medium indirect light (a couple of metres from a window) | Keep wet to consistently moist at all times; water whenever the surface is not damp | Pet-safe |
| Ossorio Gold Umbrella Pine | Bright indirect light (just back from a sunny window) | Once every 7-10 days, keeping soil consistently moist throughout the growing season | Mildly toxic to pets |
| Osteospermum 'Akila Daisy White' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 4-7 days | Pet-safe |
| Osteospermum 'Sunny Serena White' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days | Pet-safe |
| Osteospermum 'Voltage Yellow' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days | Pet-safe |
| Othello Ligularia | Medium indirect light (a couple of metres from a window) | Keep permanently moist; water deeply 2-3 times weekly, daily during heat | Mildly toxic to pets |
| Ovate Maiden Fern | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water when the top 2-3 cm begin to dry, roughly weekly in dry weather | Mildly toxic to pets |
| Overdam Feather Reed Grass | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 2 weeks once established | Pet-safe |
| Overdam Variegated Feather Reed Grass | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, about weekly; tolerates occasionally damp soil | Pet-safe |
| Owl Eye Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, approximately every 10-14 days in summer; once every 5-8 weeks in winter | Pet-safe |
| Owl Eyes Cactus | Direct sun (at least 4-6 hours) | When the soil is bone dry, roughly every 2-3 weeks in spring and summer; nearly dry in winter | Pet-safe |
| Ox Tongue | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in summer, monthly or less in winter | Pet-safe |
| Ox Tongue Plant | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Oxeye daisy | Direct sun (at least 4-6 hours) | Minimal once established; water during prolonged drought only | Mildly toxic to pets |
| Oxford and Cambridge Grape Hyacinth | Bright indirect light (just back from a sunny window) | Rainfall usually sufficient; water during prolonged dry spells in spring | Toxic to pets |
| Oxlip | Medium indirect light (a couple of metres from a window) | Regularly; keep soil consistently moist, especially in summer | Mildly toxic to pets |
| Oxydendrum arboreum | Direct sun (at least 4-6 hours) | Weekly while establishing; regular watering in dry spells | Mildly toxic to pets |
| Pachycereus schottii | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 2-3 weeks in summer; sparingly in winter | Mildly toxic to pets |
| Pachyveria 'Powder Puff' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer | Pet-safe |
| Pacific Dogwood | Bright indirect light (just back from a sunny window) | Regular deep watering, especially in summer; do not let the root zone dry out | Pet-safe |
| Pacific Silver Fir | Bright indirect light (just back from a sunny window) | Regularly during establishment; relies on natural rainfall when mature | Pet-safe |
| Paeonia lactiflora 'Bowl of Beauty' | Direct sun (at least 4-6 hours) | Deeply about once a week through spring and early summer; taper off after dormancy | Toxic to pets |
| Paeonia lactiflora 'Festiva Maxima' | Direct sun (at least 4-6 hours) | Deeply about once a week during the growing season; less once dormant | Toxic to pets |
| Paeonia lactiflora 'Karl Rosenfield' | Direct sun (at least 4-6 hours) | Deeply about once a week during active growth; reduce after dormancy | Toxic to pets |
| Paeonia mlokosewitschii | Direct sun (at least 4-6 hours) | Deeply about once a week in the growing season; minimal once dormant | Toxic to pets |
| Pagoda Dogwood | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water deeply weekly in the first two seasons and during droughts | Pet-safe |
| Painted Daisy | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce after flowering and in winter | Mildly toxic to pets |
| Painted Flowering Maple | Bright indirect light (just back from a sunny window) | Water when top 1–2 cm of compost dries; less in winter | Mildly toxic to pets |
| Painted Lady Gladiolus | Direct sun (at least 4-6 hours) | Moderate during autumn–spring growing season; completely dry in summer dormancy | Toxic to pets |
| Painted Lady sweet pea | Direct sun (at least 4-6 hours) | Every 3–5 days; daily in hot weather | Toxic to pets |
| Painted Masdevallia | Medium indirect light (a couple of metres from a window) | Water when medium is nearly dry, roughly every 1-2 days in active growth | Pet-safe |
| Painted Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist throughout the growing season; never allow soil to dry out. | Mildly toxic to pets |
| Pale Beardtongue | Direct sun (at least 4-6 hours) | Low; highly drought-tolerant once established | Mildly toxic to pets |
| Pale Coryphantha | Direct sun (at least 4-6 hours) | When the soil is fully dry, every 10-14 days in summer; every 4-6 weeks or less in winter | Pet-safe |
| Pale Pitcher Plant | Direct sun (at least 4-6 hours) | Keep soil permanently wet; refill the standing tray as it dries | Pet-safe |
| Pale Purple Coneflower | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; weekly while establishing, then rarely | Pet-safe |
| Pale Purple Coneflower | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry; highly drought-tolerant once established after the first season | Mildly toxic to pets |
| Pale Silver Skin Plant | Direct sun (at least 4-6 hours) | Every 2–4 weeks in late summer through autumn (active growth into flowering); water sparingly in spring; completely withheld mid-summer | Pet-safe |
| Pale Vygie | Direct sun (at least 4-6 hours) | Every 3–4 weeks established; more frequent in first season | Pet-safe |
| Pale Yellow Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist through spring; reduce during summer dormancy | Mildly toxic to pets |
| Pale-Leaved Sunflower | Direct sun (at least 4-6 hours) | Weekly until established, then every 1-2 weeks | Pet-safe |
| Palibin Dwarf Korean Lilac | Direct sun (at least 4-6 hours) | Every 7-10 days during dry spells; drought-tolerant once established | Mildly toxic to pets |
| Palinha's Rock Rose | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| palm sedge | Medium indirect light (a couple of metres from a window) | Consistently moist; water whenever the top 2 cm of soil dries | Pet-safe |
| Palmer's Indian Mallow | Direct sun (at least 4-6 hours) | Low; deep, infrequent irrigation once established | Mildly toxic to pets |
| Palmetto Sedge | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil is dry, roughly every 5-8 days | Pet-safe |
| Palo Alto Sweetgum | Direct sun (at least 4-6 hours) | Regular in first 2–3 years; moderate once established | Mildly toxic to pets |
| Pampas Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; thereafter only in prolonged drought | Pet-safe |
| Panama Rose Shrub | Direct sun (at least 4-6 hours) | Once per week during dry seasons; minimal during wet seasons | Mildly toxic to pets |
| Panda Face Ginger | Medium indirect light (a couple of metres from a window) | Every 7–10 days in the growing season; reduce in winter | Mildly toxic to pets |
| Panicle Fuchsia | Bright indirect light (just back from a sunny window) | Regular — keep just moist | Pet-safe |
| Panicle Hydrangea 'Pinky Winky' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 3-5 days in summer | Toxic to pets |
| Panicle Hydrangea 'Pinky Winky' | Direct sun (at least 4-6 hours) | When the top 2-4 cm of soil is dry, regularly through summer | Toxic to pets |
| Panicle Hydrangea 'Vanilla Strawberry' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 3-5 days in summer | Toxic to pets |
| Panicled Corn Lily | Direct sun (at least 4-6 hours) | Moderate in autumn-to-spring growth; completely dry in summer | Mildly toxic to pets |
| Pansy | Direct sun (at least 4-6 hours) | Twice-weekly watering | Pet-safe |
| Paper Birch | Direct sun (at least 4-6 hours) | Weekly in the first 3 years; every 10–14 days once established, more in summer heat | Pet-safe |
| Paper Spine Cactus | Direct sun (at least 4-6 hours) | When fully dry, about every 2-3 weeks in summer and roughly monthly or less in winter | Pet-safe |
| Parker's jasmine | Bright indirect light (just back from a sunny window) | Every 10–14 days; highly drought-tolerant once established | Mildly toxic to pets |
| Parkinson's Epidendrum | Bright indirect light (just back from a sunny window) | Every 3–5 days in active growth; reduced in winter | Pet-safe |
| Parrotia persica | Direct sun (at least 4-6 hours) | Weekly while establishing in the first 2-3 years; rarely thereafter | Mildly toxic to pets |
| Parsley Fern | Bright indirect light (just back from a sunny window) | Maintain consistent moisture; never allow to dry out completely | Mildly toxic to pets |
| Parsons Juniper | Direct sun (at least 4-6 hours) | Water deeply during the first season; afterward only in extended drought | Toxic to pets |
| Parthenocissus henryana | Bright indirect light (just back from a sunny window) | Keep young plants moist; water established plants only in drought | Toxic to pets |
| Parthenocissus quinquefolia | Bright indirect light (just back from a sunny window) | Water through the first one to two seasons, then only in drought | Toxic to pets |
| Parthenocissus tricuspidata | Bright indirect light (just back from a sunny window) | Water young plants in dry spells until established, then rarely | Toxic to pets |
| Partridgeberry | Low light (north window or shaded room) | Keep soil evenly moist; water when the top 1–2 cm begins to dry | Pet-safe |
| Passiflora 'Incense' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, every 3-5 days in summer heat | Mildly toxic to pets |
| Passiflora caerulea | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in growth | Mildly toxic to pets |
| Passiflora incarnata | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-7 days in summer | Mildly toxic to pets |
| Pat Austin Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, increasing in hot, dry spells | Pet-safe |
| Pau's Germander | Direct sun (at least 4-6 hours) | Very infrequently; relies on natural rainfall once established | Mildly toxic to pets |
| Paul's Glory Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Paul's Himalayan Musk Rose | Direct sun (at least 4-6 hours) | Deep soak weekly through the first two growing seasons; established plants rarely need watering | Pet-safe |
| Paulownia tomentosa | Direct sun (at least 4-6 hours) | Water weekly while establishing in the first two seasons, then rely largely on rainfall | Mildly toxic to pets |
| Peacock Moraea | Direct sun (at least 4-6 hours) | Regular watering autumn to late spring; completely dry in summer | Toxic to pets |
| Peacock Pink | Direct sun (at least 4-6 hours) | Low; allow soil to dry thoroughly between waterings | Mildly toxic to pets |
| Pearson's Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season (autumn to early spring); once per month or less in summer | Toxic to pets |
| Pebbled Tiger Jaws | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 14–21 days in the growing season and sparingly every 4–6 weeks in winter | Mildly toxic to pets |
| Peculiar Cheiridopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn–spring; none in summer | Pet-safe |
| Pelargonium 'Ardens' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth; minimal in summer rest | Toxic to pets |
| Pelargonium 'Bird Dancer' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 7-10 days in growth | Toxic to pets |
| Pelargonium 'Deacon Barbecue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 4-8 days in growth | Toxic to pets |
| Pelargonium 'Deacon Fireball' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 4-8 days in growth | Toxic to pets |
| Pelargonium 'Deacon Mandarin' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 4-8 days in growth | Toxic to pets |
| Pelargonium 'Distinction' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Dolly Varden' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-7 days in growth | Toxic to pets |
| Pelargonium 'Flower of Spring' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost dries, roughly every 5-7 days in active growth | Toxic to pets |
| Pelargonium 'Frank Headley' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Happy Thought' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Lord Bute' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of compost is dry, roughly every 5-9 days in summer | Toxic to pets |
| Pelargonium 'Madame Layal' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of compost dries, about every 5-9 days in summer | Toxic to pets |
| Pelargonium 'Mr Wren' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Mrs Pollock' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Mystery' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, about every 5-7 days in summer | Toxic to pets |
| Pelargonium 'Occold Lagoon' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 4-7 days in summer | Toxic to pets |
| Pelargonium 'Occold Shield' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Paton's Unique' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Toxic to pets |
| Pelargonium 'Paul Crampel' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Rollisson's Unique' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, about every 5-7 days in summer | Toxic to pets |
| Pelargonium 'Scarlet Unique' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-7 days in summer | Toxic to pets |
| Pelargonium 'Solferino' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Stellar Hannaford Star' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Tip Top Duet' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Vancouver Centennial' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 5-10 days in growth | Toxic to pets |
| Pelargonium 'Wilhelm Langguth' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, about every 5-7 days in summer | Toxic to pets |
| Pelargonium carnosum | Direct sun (at least 4-6 hours) | When the gritty mix is fully dry, about every 10-14 days in growth; sparingly in summer dormancy | Toxic to pets |
| Pelargonium echinatum | Direct sun (at least 4-6 hours) | Sparingly in the autumn-to-spring growing season; keep nearly dry in summer dormancy | Toxic to pets |
| Pelargonium fulgidum | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in growth | Toxic to pets |
| Pelargonium gibbosum | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth; much less in summer dormancy | Toxic to pets |
| Pelargonium peltatum 'Amethyst' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost dries, often every 3-7 days in summer baskets | Toxic to pets |
| Pelargonium peltatum 'Barrocas' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 4-7 days in summer | Toxic to pets |
| Pelargonium peltatum 'Roi des Balcons Lilas' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost dries, often every 3-7 days in summer | Toxic to pets |
| Pelargonium peltatum 'Sofie Cascade' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost dries, often every 3-7 days in summer | Toxic to pets |
| Pelargonium peltatum 'Tomcat' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days in summer | Toxic to pets |
| Pelargonium triste | Direct sun (at least 4-6 hours) | Moderately in the autumn-spring growing season; keep dry during summer dormancy | Toxic to pets |
| Pelargonium x domesticum 'Burgundy' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Pelargonium x domesticum 'Carisbrooke' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Pelargonium x domesticum 'Chocolate Blotch' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, about every 5-7 days in growth | Toxic to pets |
| Pelargonium x domesticum 'Hazel Carey' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, about every 5-7 days in growth | Toxic to pets |
| Pelargonium x domesticum 'Lavender Grand Slam' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Pelargonium-Flowered Stork's Bill | Direct sun (at least 4-6 hours) | Water sparingly; allow soil to dry out between waterings | Mildly toxic to pets |
| Pelotazo Mallow | Direct sun (at least 4-6 hours) | Every 10–21 days in summer; monthly or less in winter | Pet-safe |
| Pencil Pine | Bright indirect light (just back from a sunny window) | Keep permanently moist; never let it dry out, watering deeply during any dry period | Mildly toxic to pets |
| Pencil-leaf Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season (autumn–spring); once per month in summer | Toxic to pets |
| Pencilled Cranesbill | Medium indirect light (a couple of metres from a window) | Occasional watering during establishment; largely self-sufficient once established | Pet-safe |
| Penelope Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | Pet-safe |
| Pennsylvania Sedge | Medium indirect light (a couple of metres from a window) | Water to establish, then largely self-sufficient; occasional deep watering in extended drought | Mildly toxic to pets |
| Penny Yellow Viola | Bright indirect light (just back from a sunny window) | When the top 1–2 cm of soil is dry, roughly every 4–6 days | Mildly toxic to pets |
| Penstemon 'Garnet' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, roughly weekly in summer | Mildly toxic to pets |
| Penstemon 'Husker Red' | Direct sun (at least 4-6 hours) | Water to establish, then only during prolonged drought; drought-tolerant once settled | Mildly toxic to pets |
| Penstemon 'Raven' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, roughly weekly in summer | Mildly toxic to pets |
| Penstemon 'Sour Grapes' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries, about weekly in summer | Mildly toxic to pets |
| Penstemon 'Stapleford Gem' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly weekly in summer, less in cool spells | Mildly toxic to pets |
| Penstemon barbatus 'Rondo' | Direct sun (at least 4-6 hours) | Water to establish, then sparingly; drought-tolerant once established | Mildly toxic to pets |
| Penstemon heterophyllus 'Electric Blue' | Direct sun (at least 4-6 hours) | Water to establish, then minimally; highly drought-tolerant once settled | Mildly toxic to pets |
| Peony 'Sarah Bernhardt' | Direct sun (at least 4-6 hours) | Deeply once a week during active growth and budding, more in drought; reduce after flowering and through dormancy | Toxic to pets |
| Peony Lotus | Direct sun (at least 4-6 hours) | Aquatic — permanently in still or gently circulating water | Mildly toxic to pets |
| Percival's Cattleya | Bright indirect light (just back from a sunny window) | Every 7-10 days in active growth; reduce to every 14-21 days after pseudobulbs mature in autumn | Pet-safe |
| Peregrina | Direct sun (at least 4-6 hours) | Every 7–14 days in the growing season; every 2–3 weeks in winter | Toxic to pets |
| Perennial Candytuft | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Perez de la Rosa's Mammillaria | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 6 weeks in winter | Pet-safe |
| Perplexing Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in the growing season; nearly dry from October to February | Pet-safe |
| Perplexing Rebutia | Direct sun (at least 4-6 hours) | Every 10–14 days in spring/summer; every 3–4 weeks in autumn; once monthly or none in winter | Pet-safe |
| Persian Jewels love-in-a-mist | Direct sun (at least 4-6 hours) | Weekly | Mildly toxic to pets |
| Persian Lily | Direct sun (at least 4-6 hours) | Once per week during active spring growth; completely dry in summer dormancy | Toxic to pets |
| Persian Rosularia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season; once a month or less in winter | Mildly toxic to pets |
| Persicaria amplexicaulis 'Alba' | Direct sun (at least 4-6 hours) | Keep soil moist; water every 3-5 days in dry spells, especially in sun | Mildly toxic to pets |
| Persicaria amplexicaulis 'Blackfield' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days during dry weather | Mildly toxic to pets |
| Persicaria amplexicaulis 'Firetail' | Direct sun (at least 4-6 hours) | Keep evenly moist; water whenever the surface starts to dry, more in heat | Mildly toxic to pets |
| Persicaria bistorta 'Superba' | Direct sun (at least 4-6 hours) | Keep soil moist; water every 3-5 days in dry conditions | Mildly toxic to pets |
| Persicaria orientalis | Direct sun (at least 4-6 hours) | About twice a week in summer, keeping soil evenly moist | Mildly toxic to pets |
| Peruvian Old Man Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 14-21 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Peruvian Oroya | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, every 10-14 days in summer | Pet-safe |
| Peruvian Pamianthe | Bright indirect light (just back from a sunny window) | Water regularly during growth; reduce significantly after flowering | Toxic to pets |
| Petunia 'Supertunia Royal Velvet' | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry, frequently daily for containers in summer | Pet-safe |
| Petunia 'Supertunia Vista Bubblegum' | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry, often daily for containers in summer heat | Pet-safe |
| Petunia 'Tidal Wave Silver' | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry; containers may need daily watering in summer | Pet-safe |
| Petunia 'Wave Purple' | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry, often daily in summer for baskets and containers | Pet-safe |
| Petunia axillaris | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry; avoid both drought and waterlogging | Pet-safe |
| Peve Minaret Bald Cypress | Direct sun (at least 4-6 hours) | Keep soil consistently moist to wet; water every 5-7 days in dry periods | Mildly toxic to pets |
| Peyote-Like Turbinicarpus | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 14-21 days in summer and once a month or less in winter | Pet-safe |
| Pflanz's Chin Cactus | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring/summer; every 3–4 weeks in autumn; almost none in winter | Pet-safe |
| Pflanz's Chin Cactus | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer; reduce to once every 4-6 weeks in winter | Pet-safe |
| Pheasant Tail Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant thereafter | Mildly toxic to pets |
| Phegopteris connectilis | Low light (north window or shaded room) | Keep soil evenly moist; water when the top 1-2 cm begins to dry, roughly every 4-6 days in growth | Pet-safe |
| Phegopteris hexagonoptera | Low light (north window or shaded room) | Keep consistently moist; water when the surface starts to dry, about every 4-6 days during growth | Pet-safe |
| Philadelphus 'Snowbelle' | Direct sun (at least 4-6 hours) | Weekly while establishing, then in dry spells | Mildly toxic to pets |
| Philadelphus 'Virginal' | Direct sun (at least 4-6 hours) | Weekly while establishing, then occasional deep watering | Mildly toxic to pets |
| Philadelphus microphyllus | Direct sun (at least 4-6 hours) | Occasional deep soak once established | Mildly toxic to pets |
| Phlomis-Like Sage | Direct sun (at least 4-6 hours) | Every 2-3 weeks once established | Pet-safe |
| Phlox maculata 'Alpha' | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply 1-2 times weekly in dry spells, more in heat | Pet-safe |
| Phlox of Sheep Annual Phlox | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Phlox paniculata 'Starfire' | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply about weekly, more in heat and drought | Pet-safe |
| Phlox subulata 'Emerald Blue' | Direct sun (at least 4-6 hours) | Water when soil is dry; drought-tolerant once established | Pet-safe |
| Phoenicean Juniper | Direct sun (at least 4-6 hours) | Water weekly when young; essentially rainfall-dependent once established | Mildly toxic to pets |
| Phragmites australis | Direct sun (at least 4-6 hours) | Keep wet to shallowly flooded year-round | Mildly toxic to pets |
| Physocarpus opulifolius 'Center Glow' | Direct sun (at least 4-6 hours) | Water weekly during the first year; established plants are drought-tolerant and need water only in extended dry spells | Mildly toxic to pets |
| Physocarpus opulifolius 'Coppertina' | Direct sun (at least 4-6 hours) | Weekly while establishing; every 1-2 weeks in dry spells once mature | Mildly toxic to pets |
| Physocarpus opulifolius 'Diabolo' | Direct sun (at least 4-6 hours) | Weekly while establishing; every 1-2 weeks in dry spells once mature | Mildly toxic to pets |
| Physocarpus opulifolius 'Little Devil' | Direct sun (at least 4-6 hours) | Weekly while establishing; every 1-2 weeks in dry spells once mature | Mildly toxic to pets |
| Physocarpus opulifolius 'Summer Wine' | Direct sun (at least 4-6 hours) | Weekly while establishing; every 1-2 weeks in dry spells once mature | Mildly toxic to pets |
| Pieris japonica Cavatine | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water when the top 3-4 cm is dry, about weekly while establishing | Toxic to pets |
| Pieris japonica Valley Rose | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water when the top 3-4 cm is dry, roughly weekly while establishing | Toxic to pets |
| Pig's Ear | Bright indirect light (just back from a sunny window) | When the soil is almost completely dry, roughly every 14 days in summer | Toxic to pets |
| Pilalo Fuchsia | Bright indirect light (just back from a sunny window) | Freely in growth; reduce in winter | Pet-safe |
| Pillans' Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during late summer through early spring; fully dry in June–August | Pet-safe |
| Pillans' Watsonia | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days during spring and early summer | Mildly toxic to pets |
| Pillwort | Direct sun (at least 4-6 hours) | Permanent shallow water or wet mud in winter; allow to dry to moist mud in summer to mimic seasonal fluctuation | Mildly toxic to pets |
| Pima Pineapple Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Pin Oak | Direct sun (at least 4-6 hours) | Regular watering during establishment; tolerates periodic waterlogging and moist soils once established | Mildly toxic to pets |
| Pincushion Cactus | Direct sun (at least 4-6 hours) | Every 10–14 days in spring/summer; monthly or less in autumn; none in winter | Pet-safe |
| Pincushion flower | Direct sun (at least 4-6 hours) | Once or twice weekly | Pet-safe |
| Pincushion Flower | Direct sun (at least 4-6 hours) | Water regularly while establishing, then when the top few centimetres of soil are dry | Mildly toxic to pets |
| Pindo Palm | Direct sun (at least 4-6 hours) | Weekly while establishing; deeply but infrequently once mature | Mildly toxic to pets |
| Pineapple Lily | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Pinecone Cactus | Direct sun (at least 4-6 hours) | When the mix is bone dry, roughly every 14-21 days in the growing season; once a month or less from October to February | Pet-safe |
| Pinemat manzanita | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to dry between waterings once established | Pet-safe |
| Pinguicula 'Tina' | Bright indirect light (just back from a sunny window) | Keep lightly moist in summer; let the surface dry slightly between waterings in winter | Mildly toxic to pets |
| Pinguicula lusitanica | Bright indirect light (just back from a sunny window) | Keep permanently wet; stand in shallow water at all times | Mildly toxic to pets |
| Pink Bower Vine | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 10–14 days in winter | Mildly toxic to pets |
| Pink Calla Lily | Bright indirect light (just back from a sunny window) | Frequently during active growth — keep soil consistently moist; reduce sharply after flowering | Toxic to pets |
| Pink Calla Lily | Bright indirect light (just back from a sunny window) | Keep evenly moist during active growth; water when the top 2 cm is dry | Toxic to pets |
| Pink Cascade Tamarisk | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Pet-safe |
| Pink Coreopsis | Direct sun (at least 4-6 hours) | Moderate to high; keep soil evenly moist | Pet-safe |
| Pink Deutzia | Direct sun (at least 4-6 hours) | Every 7-10 days during dry periods; drought-tolerant once established | Pet-safe |
| Pink Fingers Orchid | Bright indirect light (just back from a sunny window) | Sparingly during active growth (autumn to spring); cease almost entirely during summer dormancy | Pet-safe |
| Pink Flowering Dogwood | Bright indirect light (just back from a sunny window) | Weekly deep watering; increase in summer heat | Pet-safe |
| Pink Ice Plant | Direct sun (at least 4-6 hours) | Weekly in spring and summer growing season; every 2–3 weeks in autumn; rarely in winter | Mildly toxic to pets |
| Pink Knock Out Rose | Direct sun (at least 4-6 hours) | About 2.5 cm of water weekly, deep soak | Pet-safe |
| Pink Lady flowering quince | Bright indirect light (just back from a sunny window) | Weekly when establishing; fortnightly in dry weather once established | Mildly toxic to pets |
| Pink Mountain Heath | Bright indirect light (just back from a sunny window) | Regular — maintain consistent moisture | Mildly toxic to pets |
| Pink Muhly Grass | Direct sun (at least 4-6 hours) | Every 10-14 days during the first growing season; minimal supplemental irrigation once established | Pet-safe |
| Pink Pampas Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; afterwards only in prolonged drought | Pet-safe |
| Pink Pampas Grass | Direct sun (at least 4-6 hours) | Weekly during the establishment year; established plants are largely self-sufficient on rainfall in temperate climates | Mildly toxic to pets |
| Pink Panther Restrepia | Medium indirect light (a couple of metres from a window) | Every 1–2 days; allow the medium to approach dryness but not fully dry | Pet-safe |
| Pink Penny Cranesbill | Bright indirect light (just back from a sunny window) | Water once or twice a week during dry periods; reduce in winter | Pet-safe |
| Pink Pitcher Plant | Direct sun (at least 4-6 hours) | Keep constantly moist to wet — sit in 2–5 cm of standing water during the growing season | Mildly toxic to pets |
| Pink Pussytoes | Direct sun (at least 4-6 hours) | Low; water only when soil is completely dry | Pet-safe |
| Pink Rock Orchid | Bright indirect light (just back from a sunny window) | When the potting medium is nearly dry, roughly every 5-7 days in summer; reduce to every 14-21 days in winter to trigger blooming | Pet-safe |
| Pink Skyrocket Foamflower | Medium indirect light (a couple of metres from a window) | Once or twice per week during the growing season; reduce in autumn and winter. | Mildly toxic to pets |
| Pink Spur Flower | Medium indirect light (a couple of metres from a window) | Moderate — water when top 3 cm of soil dries out | Mildly toxic to pets |
| Pink Storm Lily | Direct sun (at least 4-6 hours) | Moderate in summer growth; minimal in winter | Toxic to pets |
| Pink Sundew | Bright indirect light (just back from a sunny window) | Tray method, continuously wet | Pet-safe |
| Pink Surprise calendula | Direct sun (at least 4-6 hours) | Every 5–7 days; reduce in cool, wet periods | Pet-safe |
| Pink Trumpet Vine | Direct sun (at least 4-6 hours) | Every 7 days in summer; every 14–21 days in winter | Mildly toxic to pets |
| Pink Variable Heron's Bill | Direct sun (at least 4-6 hours) | Low — infrequent, allowing soil to dry between waterings | Mildly toxic to pets |
| Pink Velvet Banana | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Pink Vygie | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; monthly or less in winter | Mildly toxic to pets |
| Pink Vygie | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is fully dry, roughly every 7-14 days in spring-summer; very sparingly in winter (once monthly or less) | Pet-safe |
| Piper's Bellflower | Direct sun (at least 4-6 hours) | Sparingly; allow near-drying between waterings | Pet-safe |
| Pipsissewa | Low light (north window or shaded room) | Sparingly — allow soil to dry almost completely between waterings; low water requirement | Mildly toxic to pets |
| Pirri-Pirri Bur | Direct sun (at least 4-6 hours) | Fortnightly once established; drought-tolerant | Pet-safe |
| Pitaya Agria | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; every 4–6 weeks in winter | Mildly toxic to pets |
| Pitcairnia-Leaved Fascicularia | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | Mildly toxic to pets |
| Pitcher Sage | Medium indirect light (a couple of metres from a window) | Every 2–4 weeks once established; deep water at planting | Mildly toxic to pets |
| PJM rhododendron | Bright indirect light (just back from a sunny window) | Weekly during establishment and dry spells; every 2 weeks once established | Toxic to pets |
| Plains Coreopsis | Direct sun (at least 4-6 hours) | Low; once established, water only during prolonged drought | Pet-safe |
| Plains Prickly Pear | Direct sun (at least 4-6 hours) | Every 2-3 weeks in the growing season (spring–summer); withhold almost entirely in autumn and winter | Mildly toxic to pets |
| Plantain-leaved Pussytoes | Bright indirect light (just back from a sunny window) | Low; drought-tolerant once established | Pet-safe |
| Plantain-Leaved Sedge | Low light (north window or shaded room) | Keep soil consistently moist; do not allow to dry out | Pet-safe |
| Pleasant Air Plant | Direct sun (at least 4-6 hours) | Mist every 2–3 days in summer; once a week in winter. | Mildly toxic to pets |
| Pleasant Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during autumn growth; none in summer | Pet-safe |
| Pleione bulbocodioides | Bright indirect light (just back from a sunny window) | Regularly during active leaf growth; reduce sharply to nearly dry through winter dormancy | Pet-safe |
| Pleione formosana | Bright indirect light (just back from a sunny window) | Regularly when in leaf and growth; reduce to occasional misting and near-dry during winter dormancy | Pet-safe |
| Pleione speciosa | Bright indirect light (just back from a sunny window) | Regularly while in leaf and growth; cut back to nearly dry during winter dormancy | Pet-safe |
| Pleiospilos bolusii | Direct sun (at least 4-6 hours) | Sparingly and seasonally: water in spring and autumn when soil is dry; keep nearly dry in mid-summer and winter | Pet-safe |
| Pleiospilos compactus | Direct sun (at least 4-6 hours) | Seasonally: water in spring and autumn when soil is dry; keep nearly dry in mid-summer and winter | Pet-safe |
| Pleiospilos nelii 'Royal Flush' | Direct sun (at least 4-6 hours) | Sparingly; soak only when soil is fully dry and leaves slightly wrinkle, roughly every 3-4 weeks in growth | Mildly toxic to pets |
| Pleiospilos simulans | Direct sun (at least 4-6 hours) | Seasonally: water in spring and autumn when soil is dry; keep nearly dry in mid-summer and winter | Pet-safe |
| Plover Eggs | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (spring–autumn); once a month or less in winter | Pet-safe |
| Plum Pudding Heuchera | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about weekly | Pet-safe |
| Plumose Shield Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days in active growth; every 10–14 days in winter | Pet-safe |
| Pochutla Chamaedorea | Medium indirect light (a couple of metres from a window) | Every 7–14 days (allow top 2 in to dry between waterings) | Pet-safe |
| Podophylla Rodgersia | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Poet's Narcissus | Bright indirect light (just back from a sunny window) | Moderate to regular during growth; tolerates more moisture than most narcissi; drier in summer | Toxic to pets |
| Poet's Narcissus | Direct sun (at least 4-6 hours) | Once or twice weekly during active growth; allow to dry after foliage dies back | Toxic to pets |
| Pohl's Air Plant | Bright indirect light (just back from a sunny window) | Soak for 20–30 minutes once per week, or mist thoroughly 2–3 times per week; reduce frequency in cool winter months. | Pet-safe |
| Point Reyes bearberry | Direct sun (at least 4-6 hours) | Low once established; water weekly for the first 1–2 seasons | Pet-safe |
| Poke Milkweed | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water during dry spells, especially in sunnier sites | Toxic to pets |
| Polypodium cambricum | Bright indirect light (just back from a sunny window) | Water during its winter growing season when the top few cm dry; keep drier in summer dormancy | Mildly toxic to pets |
| Polypodium cambricum 'Cambricum' | Bright indirect light (just back from a sunny window) | Water through its autumn-to-spring growing season when the top few cm dry; keep drier in summer | Mildly toxic to pets |
| Polypody Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of medium is dry, roughly every 7-10 days | Pet-safe |
| Polystichum aculeatum | Low light (north window or shaded room) | Keep soil consistently moist; water every 5-7 days in dry spells once established | Pet-safe |
| Polystichum makinoi | Low light (north window or shaded room) | Keep evenly moist; water every 5-7 days during dry weather | Pet-safe |
| Polystichum neolobatum | Low light (north window or shaded room) | Keep consistently moist; water every 5-7 days in dry conditions | Pet-safe |
| Polystichum setiferum 'Divisilobum' | Low light (north window or shaded room) | Keep evenly moist; water deeply during dry spells, roughly weekly in summer | Pet-safe |
| Polystichum setiferum 'Plumosum Densum' | Low light (north window or shaded room) | Keep evenly moist; water deeply during dry spells, roughly weekly in summer | Pet-safe |
| Pomegranate Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, every 2-5 days in summer heat | Mildly toxic to pets |
| Pond Cypress | Direct sun (at least 4-6 hours) | Keep consistently moist; tolerates standing water and periodic flooding | Mildly toxic to pets |
| Pontederia cordata | Direct sun (at least 4-6 hours) | Keep in standing water year-round | Mildly toxic to pets |
| Pontederia cordata 'Alba' | Direct sun (at least 4-6 hours) | Keep in standing water year-round | Mildly toxic to pets |
| Pontederia cordata 'Pink Pons' | Direct sun (at least 4-6 hours) | Keep in standing water year-round | Mildly toxic to pets |
| Pony Tails Grass | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then minimal | Mildly toxic to pets |
| Poplar-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Low — establishment watering then rain-fed | Mildly toxic to pets |
| Porcupine Grass | Direct sun (at least 4-6 hours) | Weekly during the first growing season; once established, every 2–3 weeks or during prolonged drought. | Mildly toxic to pets |
| Port St. Johns Creeper | Direct sun (at least 4-6 hours) | Every 7 days during active growth; reduce in winter | Mildly toxic to pets |
| Portuguese heath | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2 weeks in the first summer; drought-tolerant once established | Pet-safe |
| Portuguese Squill | Direct sun (at least 4-6 hours) | Water moderately in spring; keep dry in summer | Toxic to pets |
| Potbelly Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week; the bulbous base dries faster than larger species so check moisture more frequently in hot, dry weather. | Pet-safe |
| Potomac Early snapdragon | Direct sun (at least 4-6 hours) | 2-3 times per week | Mildly toxic to pets |
| Pouch Flower | Medium indirect light (a couple of metres from a window) | When the top of the compost begins to feel barely dry | Mildly toxic to pets |
| Powder Puff Cactus | Direct sun (at least 4-6 hours) | When the soil is bone dry, roughly every 2-3 weeks in spring and summer; little to none in winter | Pet-safe |
| Powder Puff Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in spring and summer; once every 4-6 weeks in winter | Pet-safe |
| Prairie Azure Sage | Direct sun (at least 4-6 hours) | Fortnightly once established | Pet-safe |
| Prairie Beardtongue | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Prairie Blazing Star | Direct sun (at least 4-6 hours) | Moderate; weekly during establishment; drought-tolerant once established | Pet-safe |
| Prairie Bluebells | Bright indirect light (just back from a sunny window) | Water sparingly once established; once per week during the flowering period, far less once the plant enters summer dormancy. | Mildly toxic to pets |
| Prairie Coreopsis | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Prairie Dock | Direct sun (at least 4-6 hours) | Every 2-4 weeks once established | Pet-safe |
| Prairie Fire Switch Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; thereafter only in extended drought | Mildly toxic to pets |
| Prairie Gentian | Direct sun (at least 4-6 hours) | Low — drought tolerant once established | Pet-safe |
| Prairie Heart-Leaved Aster | Direct sun (at least 4-6 hours) | Low to moderate — drought tolerant | Pet-safe |
| Prairie Milkweed | Direct sun (at least 4-6 hours) | Moderate; tolerates moist conditions better than most milkweeds | Toxic to pets |
| Prairie Rosinweed | Direct sun (at least 4-6 hours) | Water to establish, then only in extended drought; drought-tolerant once rooted | Mildly toxic to pets |
| Prairie Sky switch grass | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water deeply every 1-2 weeks while young | Mildly toxic to pets |
| Prairie Smoke | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought; drought-tolerant once rooted | Mildly toxic to pets |
| Prairie Trillium | Medium indirect light (a couple of metres from a window) | Water regularly to keep soil evenly moist during spring growing season; reduce significantly once dormant in midsummer | Mildly toxic to pets |
| Pretty Crocus | Direct sun (at least 4-6 hours) | Low — rainfall-dependent during active growth; fully dry during summer dormancy | Mildly toxic to pets |
| Pretty Face | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry completely between waterings, roughly every 14-21 days during active growth | Pet-safe |
| Pretty Living Stone | Direct sun (at least 4-6 hours) | Only when the old leaf pair is fully shrivelled (during active growth, roughly every 2-3 weeks); no water during leaf renewal | Pet-safe |
| Pretty Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14 days in summer and once every 6-8 weeks in winter | Pet-safe |
| Prickly Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; monthly or less in winter | Toxic to pets |
| Prickly heath | Bright indirect light (just back from a sunny window) | Regular; keep evenly moist | Toxic to pets |
| Prickly Heath Bell's Seedling | Bright indirect light (just back from a sunny window) | Regularly during the growing season; keep soil moist | Mildly toxic to pets |
| Prickly Ice Plant | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in spring and summer; once monthly or less in winter | Pet-safe |
| Prickly Juniper | Direct sun (at least 4-6 hours) | Water fortnightly when young; minimal irrigation once established | Mildly toxic to pets |
| Prickly Shield Fern | Medium indirect light (a couple of metres from a window) | Weekly; drought-tolerant once established | Pet-safe |
| Pride of Rochester Deutzia | Direct sun (at least 4-6 hours) | Every 7-10 days during dry spells; drought-tolerant once established | Pet-safe |
| Primos' Vanheerdea | Direct sun (at least 4-6 hours) | Every 14-21 days during autumn to spring when the soil is completely dry; no water in summer | Mildly toxic to pets |
| Primrose | Medium indirect light (a couple of metres from a window) | Weekly watering | Toxic to pets |
| Primrose Huernia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in summer; monthly or less in winter | Mildly toxic to pets |
| Primula × polyantha | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil starts to dry, roughly every 3-5 days | Toxic to pets |
| Primula farinosa | Bright indirect light (just back from a sunny window) | Keep evenly moist in growth; water whenever the surface dries | Toxic to pets |
| Primula japonica | Bright indirect light (just back from a sunny window) | Keep wet at all times; never let the soil dry out | Toxic to pets |
| Primula malacoides | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil starts to dry, roughly every 3-5 days | Toxic to pets |
| Primula Obconica | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of soil is dry, roughly every 3-5 days while flowering | Mildly toxic to pets |
| Prince Albert's Yew | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply during dry spells and avoid letting the rootball dry out | Mildly toxic to pets |
| Prince Masdevallia | Medium indirect light (a couple of metres from a window) | Daily to every 2 days; medium should remain evenly moist at all times | Pet-safe |
| Prince of Wales Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then minimal | Mildly toxic to pets |
| Princess Alexandra of Kent Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; more in heat or containers | Pet-safe |
| Proliferous Pleurothallis | Medium indirect light (a couple of metres from a window) | When the medium surface just starts to dry, roughly every 4-6 days | Pet-safe |
| Prosperity Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season, more in heat | Pet-safe |
| Protruding Air Plant | Bright indirect light (just back from a sunny window) | 2–3 times per week misting, or a 20-minute soak once a week | Pet-safe |
| Prunus 'Accolade' | Direct sun (at least 4-6 hours) | Water deeply weekly for the first two seasons; established trees rely on rainfall | Toxic to pets |
| Prunus 'Kanzan' | Direct sun (at least 4-6 hours) | Water deeply weekly for the first two seasons; established trees rely on rainfall | Toxic to pets |
| Prunus 'Spire' | Direct sun (at least 4-6 hours) | Water regularly for the first 2-3 years; established trees need water only in prolonged dry spells | Toxic to pets |
| Prunus maackii | Direct sun (at least 4-6 hours) | Water young trees deeply every 7-14 days in dry weather for the first two seasons; established trees are fairly drought-tolerant | Toxic to pets |
| Prunus padus | Direct sun (at least 4-6 hours) | Water regularly while establishing; mature trees rarely need irrigation except in extended drought | Toxic to pets |
| Prunus serrula | Direct sun (at least 4-6 hours) | Keep soil evenly moist in the first 2-3 years; established trees need watering only in prolonged summer drought | Toxic to pets |
| Prunus subhirtella 'Autumnalis' | Direct sun (at least 4-6 hours) | Water regularly during establishment; mature trees need watering only in prolonged summer drought | Toxic to pets |
| Przewalski's Leopard Plant | Medium indirect light (a couple of metres from a window) | Every 3-5 days in the growing season; soil should remain evenly moist to slightly wet | Mildly toxic to pets |
| Przewalskii Ligularia | Medium indirect light (a couple of metres from a window) | Keep constantly moist; water deeply 2-3 times weekly, more in heat | Mildly toxic to pets |
| Pseudolarix amabilis | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing; mature trees mostly rainfall-dependent but watered in drought | Mildly toxic to pets |
| Puebla Air Plant | Bright indirect light (just back from a sunny window) | Soak 20–30 minutes once a week; mist 2–3 times weekly in dry conditions | Pet-safe |
| Pumila Dwarf Pampas Grass | Direct sun (at least 4-6 hours) | Weekly during establishment; afterwards only in drought | Pet-safe |
| Pumila Norway Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing; deep soak when the top 5 cm of soil dries | Pet-safe |
| Punting-Pole Bamboo | Direct sun (at least 4-6 hours) | Once or twice per week during growing season; less frequent in winter | Pet-safe |
| Purging Jatropha | Direct sun (at least 4-6 hours) | Every 3–4 weeks in the growing season; none to once a month in winter dormancy | Toxic to pets |
| Purple Air Plant | Bright indirect light (just back from a sunny window) | Soak 20–30 minutes once a week; mist sparingly 1–2 times weekly | Pet-safe |
| Purple Bergenia | Medium indirect light (a couple of metres from a window) | Every 7-14 days; relatively drought-tolerant once established | Mildly toxic to pets |
| Purple Bladderwort | Bright indirect light (just back from a sunny window) | Fully aquatic — kept submerged or floating in distilled, rainwater, or very low-mineral water at all times | Pet-safe |
| Purple Bugle | Medium indirect light (a couple of metres from a window) | Moderate; consistent moisture preferred | Mildly toxic to pets |
| Purple Cliff Brake | Direct sun (at least 4-6 hours) | every 2-3 weeks | Mildly toxic to pets |
| Purple Cliff Brake Fern | Bright indirect light (just back from a sunny window) | When the soil is nearly dry throughout, roughly every 10-14 days in summer | Pet-safe |
| Purple Coneflower | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; about weekly while establishing, then only in drought | Pet-safe |
| Purple Cyclamen | Medium indirect light (a couple of metres from a window) | Low in summer, moderate during active growth (late summer to spring) | Toxic to pets |
| Purple Fingers | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn through early spring; none in summer | Pet-safe |
| Purple Fountain Grass | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil dries, roughly weekly in the ground and more often in containers | Pet-safe |
| Purple Heart | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in growth | Toxic to pets |
| Purple Japanese Barberry | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Purple Jerusalem Sage | Direct sun (at least 4-6 hours) | Low — once every 2–3 weeks in the growing season; minimal in winter | Mildly toxic to pets |
| Purple Milkweed | Direct sun (at least 4-6 hours) | Keep evenly moist; water during dry periods, especially while establishing | Toxic to pets |
| Purple Mountain Heath | Bright indirect light (just back from a sunny window) | Regular — keep consistently moist but never waterlogged | Mildly toxic to pets |
| Purple Mountain Saxifrage | Bright indirect light (just back from a sunny window) | Every 5–7 days during the growing season; maintain slight moisture at all times | Pet-safe |
| Purple Mullein | Direct sun (at least 4-6 hours) | Every 7–10 days during active growth and dry spells | Mildly toxic to pets |
| Purple Paintbrush | Direct sun (at least 4-6 hours) | Rarely; dry to very dry conditions | Mildly toxic to pets |
| Purple Pitcher Plant | Direct sun (at least 4-6 hours) | Keep constantly moist by standing the pot in a tray of rainwater or distilled water at all times | Pet-safe |
| Purple Poppy Mallow | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; deeply drought-tolerant | Pet-safe |
| Purple Prairie Clover | Direct sun (at least 4-6 hours) | Water to establish; thereafter drought-tolerant, rarely needs watering | Mildly toxic to pets |
| Purple Prickly Pear | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and almost never in winter | Pet-safe |
| Purple Roscoea | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry during the growing season, roughly every 10-14 days; minimal to none in winter | Mildly toxic to pets |
| Purple Royal Fern | Medium indirect light (a couple of metres from a window) | Freely and consistently — never allow to dry out | Pet-safe |
| Purple Royal Fern | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist to wet; may need watering every 2-3 days in summer heat | Pet-safe |
| Purple Siberian Melic | Bright indirect light (just back from a sunny window) | Every 1–2 weeks during the growing season | Pet-safe |
| Purple Stelis | Medium indirect light (a couple of metres from a window) | Every 2–3 days in active growth; reduce slightly in cooler months | Pet-safe |
| Purple Sun African Daisy | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Purple toadflax | Direct sun (at least 4-6 hours) | Rarely needed once established; water young plants weekly until established | Mildly toxic to pets |
| Purple Vygie | Direct sun (at least 4-6 hours) | Every 3–4 weeks established; more in active growth | Pet-safe |
| Purple Wreath | Direct sun (at least 4-6 hours) | Every 5–7 days during the growing season; every 10–14 days in cooler months | Mildly toxic to pets |
| Purple-flowered Sage | Bright indirect light (just back from a sunny window) | Moderate; water when the top 3–5 cm of soil is dry | Mildly toxic to pets |
| Purple-Top Germander | Bright indirect light (just back from a sunny window) | Weekly to fortnightly in summer; reduce in autumn and winter | Mildly toxic to pets |
| Purpurascens Flame Grass | Direct sun (at least 4-6 hours) | Weekly to establish, then mostly rainfall except in drought | Mildly toxic to pets |
| Purpus's Dioon | Direct sun (at least 4-6 hours) | Every 2–4 weeks (growing season); monthly or less in winter | Toxic to pets |
| Pusillus Miniature Sweet Flag | Bright indirect light (just back from a sunny window) | Keep constantly moist to wet; water whenever the surface starts to dry, every 2-4 days in pots | Mildly toxic to pets |
| Pygmy Bamboo | Bright indirect light (just back from a sunny window) | 2–3 times per week in growing season, once per week in winter | Pet-safe |
| Pygmy Cactus | Bright indirect light (just back from a sunny window) | When soil is dry, about every 7-10 days in growth; keep dry in winter | Pet-safe |
| Pygmy Sundew | Direct sun (at least 4-6 hours) | Keep soil moist via a shallow tray; top up as it dries | Pet-safe |
| Pygmy Tongue Plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer; once every 4-6 weeks or less in winter | Mildly toxic to pets |
| Pygmy Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic — crown submerged 10–25 cm (4–10 in) below water surface | Pet-safe |
| Pygmy Water Lily | Direct sun (at least 4-6 hours) | Aquatic — submerged in still water permanently | Toxic to pets |
| Pyracantha angustifolia | Direct sun (at least 4-6 hours) | When the top 2-3 cm is dry, often daily in summer and every few days in cooler weather | Mildly toxic to pets |
| Pyramidalis Arborvitae | Direct sun (at least 4-6 hours) | Two to three times weekly when establishing; weekly once rooted in | Mildly toxic to pets |
| Pyrenean Heron's Bill | Direct sun (at least 4-6 hours) | Water every 7-10 days in summer; minimal watering from autumn to spring | Mildly toxic to pets |
| Pyrenean Lily | Bright indirect light (just back from a sunny window) | Weekly during active growth; reduce after flowering | Toxic to pets |
| Pyrenean Merendera | Direct sun (at least 4-6 hours) | Minimal; naturally dry in summer | Toxic to pets |
| Pyrenean Ramonda | Medium indirect light (a couple of metres from a window) | Once or twice a week in the growing season; minimal in winter | Pet-safe |
| Pyrenean Rock Jasmine | Direct sun (at least 4-6 hours) | Low — water from below and keep dry in winter | Mildly toxic to pets |
| Pyrenean Star of Bethlehem | Bright indirect light (just back from a sunny window) | Low to moderate during growth; dry in summer dormancy | Toxic to pets |
| Pyrrosia hastata | Bright indirect light (just back from a sunny window) | When soil is nearly dry throughout, roughly every 7-12 days | Mildly toxic to pets |
| QIS Mix statice | Direct sun (at least 4-6 hours) | Every 7–10 days when actively growing; reduce in cool or wet weather | Pet-safe |
| Quaking Grass | Direct sun (at least 4-6 hours) | Water moderately; drought-tolerant once established | Mildly toxic to pets |
| Queen of Night Tulip | Direct sun (at least 4-6 hours) | Water at planting; rely on rainfall during growth; dry during dormancy | Toxic to pets |
| Queen of the Andes | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is completely dry, roughly every 10-14 days in summer and less in winter | Mildly toxic to pets |
| Queen of the Night Cereus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days in summer and every 4-6 weeks in winter | Pet-safe |
| Queen Olga's Snowdrop | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry during active growth, roughly every 7-10 days | Toxic to pets |
| Queensland Kauri | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days | Mildly toxic to pets |
| Quehl's Chin Cactus | Bright indirect light (just back from a sunny window) | When soil is completely dry, roughly every 10-14 days in the growing season; once every 4-6 weeks in winter | Pet-safe |
| Quehlianum Chin Cactus | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 10-14 days in active growth; none in winter | Pet-safe |
| Quelch's Bladderwort | Bright indirect light (just back from a sunny window) | Keep sphagnum constantly moist during active growth; reduce slightly in winter rest period | Mildly toxic to pets |
| Quercus coccinea | Direct sun (at least 4-6 hours) | Water young trees deeply every 10-14 days in dry weather through the first two seasons; established trees are drought-tolerant | Toxic to pets |
| Quercus robur 'Fastigiata' | Direct sun (at least 4-6 hours) | Water young trees deeply every 10-14 days in dry spells for the first two seasons; established oaks are very drought-tolerant | Toxic to pets |
| Rabiea albinota | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in active growth; keep nearly dry in winter | Mildly toxic to pets |
| Raceme Masdevallia | Medium indirect light (a couple of metres from a window) | Daily or every 1-2 days; medium should not dry out between waterings | Pet-safe |
| Radicalis Palm | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growing season; every 14–21 days in winter | Pet-safe |
| Ragged Robin | Bright indirect light (just back from a sunny window) | High; keep consistently moist | Mildly toxic to pets |
| Rainbow Hedgehog Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Rainbow Pincushion | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Rainer's Bellflower | Direct sun (at least 4-6 hours) | Moderately during growth; sparingly in winter | Pet-safe |
| Rambling Sundew | Bright indirect light (just back from a sunny window) | Tray method during winter growing season (June–November); completely dry summer dormancy (December–May in the southern hemisphere) | Mildly toxic to pets |
| Ranunculus aquatilis | Direct sun (at least 4-6 hours) | Submerged with floating leaves; grow in 0.1-1 m of clear water | Toxic to pets |
| Ranunculus asiaticus | Direct sun (at least 4-6 hours) | Keep soil evenly moist during growth and bloom; reduce sharply as foliage yellows and the plant enters dormancy | Toxic to pets |
| Ranunculus asiaticus 'Cloni Success Arancio' | Direct sun (at least 4-6 hours) | Keep soil consistently moist but never waterlogged during active growth; reduce sharply as foliage yellows after flowering | Toxic to pets |
| Ranunculus asiaticus 'Elegance Bianco' | Direct sun (at least 4-6 hours) | Keep soil evenly moist during growth and flowering; cut back watering as foliage yellows at the end of the season | Toxic to pets |
| Ranunculus asiaticus 'Mache' | Direct sun (at least 4-6 hours) | Maintain even soil moisture during growth and flowering; taper off as the foliage yellows toward dormancy | Toxic to pets |
| Raspberry Splash Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry conditions, more in pots | Mildly toxic to pets |
| Rat Tail Cactus | Bright indirect light (just back from a sunny window) | Every 1–2 weeks in spring and summer; every 3–4 weeks in winter | Pet-safe |
| Rat Tail Cactus | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in spring and summer; reduce to every 3-4 weeks in winter | Pet-safe |
| Rattlesnake Fern | Medium indirect light (a couple of metres from a window) | Moderate — consistently moist but never waterlogged | Mildly toxic to pets |
| Rattlesnake Master | Direct sun (at least 4-6 hours) | Water to establish, then rarely; highly drought-tolerant once rooted | Mildly toxic to pets |
| Rauwolff's Eminium | Direct sun (at least 4-6 hours) | Moderate during spring growing season; bone dry in summer dormancy | Toxic to pets |
| Ravenea Glauca | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Ravenna Grass | Direct sun (at least 4-6 hours) | Weekly while establishing in year one, then only during prolonged drought | Mildly toxic to pets |
| Rayed Broom | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Toxic to pets |
| Rebutia krainziana | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 10-14 days in summer; none in winter | Mildly toxic to pets |
| Recurved Leucothoe | Medium indirect light (a couple of metres from a window) | Regularly; maintain consistently moist soil throughout the growing season | Toxic to pets |
| Red Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, every 1-2 weeks in warm growth | Toxic to pets |
| Red Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 3–5 days (keep evenly moist; allow top 2 cm to dry) | Toxic to pets |
| Red Beauty Japanese Painted Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season, reduce in winter | Pet-safe |
| Red Campion | Medium indirect light (a couple of metres from a window) | Moderate; keep moist | Mildly toxic to pets |
| Red Ceratostylis | Bright indirect light (just back from a sunny window) | When the surface of the medium begins to dry, roughly every 4-6 days | Pet-safe |
| Red Dragon Venus Flytrap | Direct sun (at least 4-6 hours) | Keep in standing water year-round except dormancy | Pet-safe |
| Red escallonia | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once established | Mildly toxic to pets |
| Red Feather Clover | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Pet-safe |
| Red Fescue | Bright indirect light (just back from a sunny window) | Infrequent — drought-tolerant once established | Pet-safe |
| Red Fir | Direct sun (at least 4-6 hours) | Regular moisture; does not tolerate summer drought well | Pet-safe |
| Red Hot Poker | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days during the growing season | Mildly toxic to pets |
| Red Inca Passionflower | Direct sun (at least 4-6 hours) | Every 3–5 days; keep consistently moist but not waterlogged | Pet-safe |
| Red larkspur | Direct sun (at least 4-6 hours) | Moderate — water once or twice weekly during spring growth; allow to dry out in summer dormancy | Toxic to pets |
| Red Latan Palm | Direct sun (at least 4-6 hours) | Every 7–14 days; allow soil to partially dry between waterings | Pet-safe |
| Red Latan Palm | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in summer; every 3-4 weeks in winter | Pet-safe |
| Red Orchid Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of mix is dry, roughly every 7-10 days in growth | Pet-safe |
| Red Pagoda | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer | Toxic to pets |
| Red Pine | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry; allow slight drying between waterings | Mildly toxic to pets |
| Red Prince Weigela | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Red Rooster Sedge | Direct sun (at least 4-6 hours) | Keep evenly moist; water once or twice weekly in heat, less in cool weather | Mildly toxic to pets |
| Red Sentinel Astilbe | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water every 3-5 days in summer, more in heat or containers | Pet-safe |
| Red Sheep Laurel | Bright indirect light (just back from a sunny window) | Moderate; keep moist | Toxic to pets |
| Red Silk Cotton Tree | Direct sun (at least 4-6 hours) | Every 7–14 days in the growing season; every 3–5 weeks in winter | Mildly toxic to pets |
| Red Torch Cleistocactus | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Red Trillium | Medium indirect light (a couple of metres from a window) | Weekly during spring; reduce as plant goes dormant in midsummer | Mildly toxic to pets |
| Red Tube Pitcher | Direct sun (at least 4-6 hours) | Keep growing medium permanently moist using a tray of 2-4 cm of rainwater at all times during the growing season | Pet-safe |
| Red Twig Dogwood 'Arctic Fire' | Direct sun (at least 4-6 hours) | Keep consistently moist; tolerates wet soil | Pet-safe |
| Red Valerian | Direct sun (at least 4-6 hours) | Drought-tolerant; water only to establish and in extended dry spells | Mildly toxic to pets |
| Red Vygie | Direct sun (at least 4-6 hours) | Every 3–4 weeks established; more frequent in first season | Pet-safe |
| Red Vygie | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is fully dry, roughly every 7-14 days in spring-summer; monthly or less in winter | Pet-safe |
| Red-bristled Dragon Orchid | Medium indirect light (a couple of metres from a window) | Every 2–3 days; roots must not dry out | Pet-safe |
| Red-petal Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting or watering every 1-2 days; never allow to dry | Pet-safe |
| Red-stemmed Sensitive Fern | Medium indirect light (a couple of metres from a window) | Keep soil continuously moist to wet; water every 2–3 days or more in dry spells | Mildly toxic to pets |
| red-twig dogwood | Bright indirect light (just back from a sunny window) | Weekly when young; tolerates both wet and dry once established | Mildly toxic to pets |
| Redvein Abutilon | Bright indirect light (just back from a sunny window) | Regularly in growth; reduced in winter | Mildly toxic to pets |
| Redvein enkianthus | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce to every 2–3 weeks in winter | Mildly toxic to pets |
| Redvein Enkianthus Red Bells | Bright indirect light (just back from a sunny window) | Regularly during the growing season; reduce in winter | Mildly toxic to pets |
| Reed Sweet-grass | Direct sun (at least 4-6 hours) | Permanently wet; grows in standing water 15–45 cm deep | Pet-safe |
| Reed Sweetgrass | Direct sun (at least 4-6 hours) | Shallow to moderate aquatic; submerged 0–30 cm; tolerates winter flooding | Mildly toxic to pets |
| Reichenbach's Air Plant | Bright indirect light (just back from a sunny window) | Soak 20–30 minutes once a week; mist 2–3 times weekly | Pet-safe |
| Reichenbach's Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in warm weather; every 2–3 days in cooler months | Pet-safe |
| Reko's Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 6-8 weeks in winter | Pet-safe |
| Repandens Yew | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, roughly weekly while establishing | Toxic to pets |
| Resurrection fern | Medium indirect light (a couple of metres from a window) | Mist or moisten every 2-4 days; let it dry between | Mildly toxic to pets |
| Resurrection Fern | Medium indirect light (a couple of metres from a window) | Allow to dry slightly between waterings; roughly every 7-10 days, or mist daily when mounted | Pet-safe |
| Resurrection Gesneriad | Medium indirect light (a couple of metres from a window) | Once a week in the growing season; sparingly in winter | Pet-safe |
| Resurrection Spike Moss | Bright indirect light (just back from a sunny window) | Can be kept moist year-round or allowed to dry fully and rehydrated on demand | Pet-safe |
| Revolute Tromotriche | Direct sun (at least 4-6 hours) | Every 3–4 weeks in the growing season; minimal to none in dormancy | Mildly toxic to pets |
| Revolution Hosta | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; deep watering 1-2 times weekly | Toxic to pets |
| Rheingold Arborvitae | Direct sun (at least 4-6 hours) | Twice weekly while establishing; weekly thereafter | Mildly toxic to pets |
| Rhinephyllum broomii | Direct sun (at least 4-6 hours) | Only once the soil is completely dry, roughly every 10-14 days in growth; keep nearly dry when dormant | Mildly toxic to pets |
| Rhododendron 'Blue Peter' | Bright indirect light (just back from a sunny window) | Deeply once or twice a week in dry weather; keep consistently moist | Toxic to pets |
| Rhododendron 'Catawbiense Boursault' | Bright indirect light (just back from a sunny window) | Keep the rootball consistently moist; water deeply 1-2 times weekly in dry spells | Toxic to pets |
| Rhododendron 'Cunningham's White' | Bright indirect light (just back from a sunny window) | Keep consistently moist; water deeply 1-2 times weekly during dry spells | Toxic to pets |
| Rhododendron 'English Roseum' | Bright indirect light (just back from a sunny window) | Deeply once a week during the growing season; reduce in winter | Toxic to pets |
| Rhododendron 'Fastuosum Flore Pleno' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil begins to dry, roughly every 7-14 days depending on conditions | Toxic to pets |
| Rhododendron 'Nova Zembla' | Bright indirect light (just back from a sunny window) | Deeply once a week; more frequently during establishment and summer heat | Toxic to pets |
| Rhododendron 'Pink Pearl' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil begins to dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Rhododendron 'PJM' | Bright indirect light (just back from a sunny window) | Keep evenly moist; water deeply 1-2 times weekly in dry spells, more in heat | Toxic to pets |
| Rhododendron 'Roseum Elegans' | Bright indirect light (just back from a sunny window) | Deeply once a week during dry spells; keep consistently moist especially in summer | Toxic to pets |
| Ribbed Brain Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season; reduce to once a month or less in winter | Pet-safe |
| Ribbon Bush | Bright indirect light (just back from a sunny window) | Every 7–10 days in growth; reduce to every 14 days in winter rest | Pet-safe |
| Ribbon Grass | Bright indirect light (just back from a sunny window) | Adaptable; keep moist for best foliage but tolerates dry once established | Mildly toxic to pets |
| Riberry | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 10–14 days for mature plants in mild conditions | Pet-safe |
| Ribes Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting; substrate must remain moist at all times | Pet-safe |
| Richard's Shield Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days; adjust seasonally | Pet-safe |
| Rigid Draba | Direct sun (at least 4-6 hours) | Every 10–14 days during growth; almost none in winter | Pet-safe |
| Rigid Goldenrod | Direct sun (at least 4-6 hours) | Low — drought tolerant once established | Pet-safe |
| Rimu | Bright indirect light (just back from a sunny window) | When the top 5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Rincon Thelocactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; rarely in winter. | Pet-safe |
| Ring Fern | Bright indirect light (just back from a sunny window) | Water when the top 3–5 cm of soil is dry — more drought-tolerant than most ferns once established | Mildly toxic to pets |
| River Water Crowfoot | Direct sun (at least 4-6 hours) | Permanently submerged in flowing or moderately moving water 15–60 cm deep | Toxic to pets |
| River Water Fern | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; check every 3-5 days | Mildly toxic to pets |
| Robin Hill serviceberry | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Robinia pseudoacacia 'Frisia' | Direct sun (at least 4-6 hours) | Water weekly while establishing, then rely on rainfall | Toxic to pets |
| Rochford Holly Fern | Low light (north window or shaded room) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in the growing season | Pet-safe |
| Rochford's Holly Fern | Low light (north window or shaded room) | Every 7–10 days; less in winter | Pet-safe |
| Rock Banana | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days in active growth | Mildly toxic to pets |
| Rock Candytuft | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; minimal in winter | Pet-safe |
| Rock Cress | Direct sun (at least 4-6 hours) | Low; water only when soil has dried out, roughly every 10–14 days in summer | Pet-safe |
| Rock Lily | Bright indirect light (just back from a sunny window) | Every 5–10 days during active growth; reduce significantly in winter rest | Pet-safe |
| Rock Liveforever | Direct sun (at least 4-6 hours) | Every 3–5 weeks in summer (near-dry dormancy), every 2–3 weeks in winter (active season) | Pet-safe |
| Rock Palm | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in summer; every 2-3 weeks in winter | Pet-safe |
| Rock Polypody | Medium indirect light (a couple of metres from a window) | Low to moderate — allow to dry slightly between waterings | Pet-safe |
| Rock Speedwell | Bright indirect light (just back from a sunny window) | Once every 7–10 days during the growing season; reduce markedly in winter. | Pet-safe |
| Rocket candytuft | Direct sun (at least 4-6 hours) | Every 7–14 days; keep moist during establishment, reduce once rooted | Pet-safe |
| Rocket Mix Snapdragon | Direct sun (at least 4-6 hours) | When the top 2–3 cm of soil is dry, roughly every 5–7 days | Pet-safe |
| Rocket Mixed snapdragon | Direct sun (at least 4-6 hours) | Every 5–7 days; maintain consistent soil moisture | Pet-safe |
| Rocky Mountain Bristlecone Pine | Direct sun (at least 4-6 hours) | Deep watering every 2-3 weeks once established; let dry between | Mildly toxic to pets |
| Rocky Mountain Juniper | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-6 days | Mildly toxic to pets |
| Rocky Mountain penstemon | Direct sun (at least 4-6 hours) | Every 14–21 days once established; very drought-tolerant | Mildly toxic to pets |
| Rocky Mountain Penstemon | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-21 days during the growing season | Mildly toxic to pets |
| Rodgersia Pinnata | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Roezl's Dracula | Medium indirect light (a couple of metres from a window) | When the medium surface just barely begins to dry, roughly every 3-5 days | Pet-safe |
| Rolfe's Masdevallia | Medium indirect light (a couple of metres from a window) | Every 1–2 days in summer; every 2–3 days in winter | Pet-safe |
| Rollers Houseleek | Direct sun (at least 4-6 hours) | Every 14-21 days in spring and summer; barely at all in winter | Pet-safe |
| Rood's Vanheerdea | Direct sun (at least 4-6 hours) | Every 14-21 days in autumn through spring; essentially none in summer | Mildly toxic to pets |
| Rooper's Red Hot Poker | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days during the growing season | Mildly toxic to pets |
| Rose campion | Direct sun (at least 4-6 hours) | Every 10–14 days; very drought-tolerant once established | Pet-safe |
| Rose Grass | Direct sun (at least 4-6 hours) | Moderate during growth; almost dry in winter dormancy | Pet-safe |
| Rose of Sharon 'Blue Bird' | Direct sun (at least 4-6 hours) | Weekly while establishing, then during dry or hot spells | Pet-safe |
| Rose of Sharon 'Diana' | Direct sun (at least 4-6 hours) | Weekly to establish, then during dry and hot periods | Pet-safe |
| Rose Pincushion Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in spring and summer; little to none in winter | Pet-safe |
| Rose Pincushion Cactus | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in the growing season; once every 4-6 weeks in winter | Pet-safe |
| Rose Queen Epimedium | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly weekly | Mildly toxic to pets |
| Rose Rain Lily | Direct sun (at least 4-6 hours) | Allow partial soil drying between waterings; dry-wet trigger cycle stimulates blooming | Toxic to pets |
| Rosebay Rhododendron | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer | Toxic to pets |
| Rosemary Barberry | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry; established plants are drought-tolerant and may need watering only in prolonged dry spells | Mildly toxic to pets |
| Rosemary-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Low — water only during establishment | Mildly toxic to pets |
| Roseraie de l'Hay Rose | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once settled | Pet-safe |
| Rosette Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 7–10 days in growth; minimal in winter | Pet-safe |
| Rosette Rock Jasmine | Direct sun (at least 4-6 hours) | Weekly in the growing season; reduce significantly in winter | Mildly toxic to pets |
| Rosinweed | Direct sun (at least 4-6 hours) | Every 2-3 weeks once established | Pet-safe |
| Rossica Major rowan | Direct sun (at least 4-6 hours) | Regular during establishment; self-sufficient once mature | Mildly toxic to pets |
| Rosy Gladiolus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days during active growth | Mildly toxic to pets |
| Rosy-Leaf Sage | Bright indirect light (just back from a sunny window) | Twice weekly in summer; weekly or less in cooler months | Mildly toxic to pets |
| Roth's Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times a week; soak 10–20 minutes weekly if conditions are dry | Pet-safe |
| Rotstrahlbusch Switch Grass | Direct sun (at least 4-6 hours) | Water weekly the first season; once established, only during prolonged drought | Mildly toxic to pets |
| Rough Bamboo | Direct sun (at least 4-6 hours) | Frequently; keep moist, especially when establishing | Pet-safe |
| Rough Blazing Star | Direct sun (at least 4-6 hours) | Water to establish, then only during extended drought | Pet-safe |
| Rough Coneflower | Direct sun (at least 4-6 hours) | Every 2-3 weeks once established | Pet-safe |
| Rough Hawk's-beard | Direct sun (at least 4-6 hours) | Low — drought-tolerant, especially in the rosette year | Pet-safe |
| Rough Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Mildly toxic to pets |
| Rough Tree Fern | Bright indirect light (just back from a sunny window) | Keep consistently moist; water every 3-5 days in the growing season, every 7-10 days in cooler months | Pet-safe |
| Rough-leaved Cape Mallow | Direct sun (at least 4-6 hours) | Water when the top 3–4 cm of soil is dry | Mildly toxic to pets |
| Round-leaf Rosularia | Direct sun (at least 4-6 hours) | Every 14–21 days during spring and summer; minimal in winter | Pet-safe |
| Round-leaved Sage | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth | Pet-safe |
| Round-leaved Wintergreen | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water whenever the top 1–2 cm of soil begins to dry | Mildly toxic to pets |
| Round-lobed Hepatica | Medium indirect light (a couple of metres from a window) | Every 5–7 days during active growth; minimal in summer dormancy | Mildly toxic to pets |
| Rounded Sweetgum | Direct sun (at least 4-6 hours) | Weekly during establishment; less once mature | Mildly toxic to pets |
| Roundleaf Sundew | Direct sun (at least 4-6 hours) | Keep saturated; stand in 1-3 cm of pure water through the growing season | Mildly toxic to pets |
| Rowallane quince | Bright indirect light (just back from a sunny window) | Weekly when establishing; every 2–3 weeks during dry spells once established | Mildly toxic to pets |
| Rowlee's Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 1–2 days in summer; every 2–4 days in cooler months | Pet-safe |
| Royal Azalea | Bright indirect light (just back from a sunny window) | Every 5-7 days in the growing season; reduce after leaf drop | Toxic to pets |
| Royal Blue Aubrieta | Direct sun (at least 4-6 hours) | Weekly in spring and autumn; infrequently in summer | Pet-safe |
| Royal Fern | Medium indirect light (a couple of metres from a window) | Keep soil constantly moist; water whenever the surface starts to dry, often 2-3 times a week in growth | Mildly toxic to pets |
| Royal Flush Split Rock | Direct sun (at least 4-6 hours) | Only during active growth: late summer through winter and into early spring; stop completely while leaves are splitting | Pet-safe |
| Royal Star Magnolia | Direct sun (at least 4-6 hours) | Weekly while young; in summer droughts for established shrubs | Pet-safe |
| Royal Trumpet Vine | Direct sun (at least 4-6 hours) | Twice weekly in summer; weekly in cooler months | Mildly toxic to pets |
| Rubrum Epimedium | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 1-2 weeks | Mildly toxic to pets |
| Ruby Ribbons Switch Grass | Direct sun (at least 4-6 hours) | Weekly during establishment; afterwards only in drought | Mildly toxic to pets |
| Rudbeckia 'Autumn Colors' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Becky Mixed' | Direct sun (at least 4-6 hours) | Every 7-10 days once established; keep containers evenly moist | Pet-safe |
| Rudbeckia 'Cherry Brandy' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Denver Daisy' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Goldsturm' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly weekly in summer, more in prolonged heat | Mildly toxic to pets |
| Rudbeckia 'Goldsturm' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days; very drought-tolerant once established | Pet-safe |
| Rudbeckia 'Henry Eilers' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7-14 days | Mildly toxic to pets |
| Rudbeckia 'Indian Summer' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Little Henry' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Pot of Gold' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Rudbeckia 'Prairie Sun' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Rudbeckia 'Sahara' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Rudbeckia 'Toto Gold' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in containers | Mildly toxic to pets |
| Rudbeckia maxima | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about weekly until established | Mildly toxic to pets |
| Ruedebusch's Schwantesia | Direct sun (at least 4-6 hours) | Every 10-14 days in the autumn-winter growing season; taper in spring; almost none from late spring through summer | Mildly toxic to pets |
| Running Tapestry Foamflower | Medium indirect light (a couple of metres from a window) | Every 5–7 days; more during summer drought | Pet-safe |
| Running Tapestry Tiarella | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply once or twice weekly in dry spells | Mildly toxic to pets |
| Rusch's Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during the active autumn-to-spring period; completely dry in summer | Pet-safe |
| Ruschia lineolata | Direct sun (at least 4-6 hours) | When the soil has fully dried, roughly every 10-14 days in growth | Mildly toxic to pets |
| Ruschia uncinata | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth | Mildly toxic to pets |
| Russell Lupin 'Band of Nobles' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Russian Arborvitae | Bright indirect light (just back from a sunny window) | Water weekly until established; drought-tolerant once mature | Mildly toxic to pets |
| Russian Olive | Direct sun (at least 4-6 hours) | Low; highly drought-tolerant | Pet-safe |
| Rusty Foxglove | Direct sun (at least 4-6 hours) | When the top few cm of soil are dry; established plants are fairly drought-tolerant | Toxic to pets |
| Rustyback Fern | Bright indirect light (just back from a sunny window) | Infrequently; allow to dry between waterings | Pet-safe |
| Ryegrass Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week or soak for 20 minutes weekly | Pet-safe |
| Rzedowski's Dioon | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer; once a month or less in winter | Toxic to pets |
| Sacchariflorus Silver Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; tolerates moist to wet soils thereafter | Mildly toxic to pets |
| Saffron Air Plant | Direct sun (at least 4-6 hours) | Twice weekly in summer, once weekly in winter | Pet-safe |
| Sage-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Deeply but infrequently once established; every 2–3 weeks in the first two summers, then rainfall alone suffices in most UK/mild US climates. | Mildly toxic to pets |
| Sagittaria latifolia | Direct sun (at least 4-6 hours) | Keep in shallow standing water year-round | Mildly toxic to pets |
| Sagittaria sagittifolia | Direct sun (at least 4-6 hours) | Keep in shallow standing water year-round | Mildly toxic to pets |
| Sakhalin Fir | Direct sun (at least 4-6 hours) | Moderate; water regularly during establishment | Pet-safe |
| Salal | Low light (north window or shaded room) | Moderate; established plants are drought-tolerant but prefer moist conditions | Pet-safe |
| Sally Holmes Rose | Direct sun (at least 4-6 hours) | Deep watering once or twice weekly | Pet-safe |
| Sally-My-Handsome | Direct sun (at least 4-6 hours) | Every 3–4 weeks in the growing season; minimal in winter | Mildly toxic to pets |
| Salmon Queen scabiosa | Direct sun (at least 4-6 hours) | Every 5–7 days in active growth; reduce in cool spells | Pet-safe |
| Samaipatensis Cactus | Direct sun (at least 4-6 hours) | When the soil is dry, about every 10-14 days in summer; sparing in winter | Pet-safe |
| San Diego Red Bougainvillea | Direct sun (at least 4-6 hours) | Every 7–14 days when established; more frequently for container plants in hot weather | Mildly toxic to pets |
| San Diego Sage | Direct sun (at least 4-6 hours) | Low; drought tolerant once established | Pet-safe |
| San Gabriel Mountains Liveforever | Bright indirect light (just back from a sunny window) | Every 2–3 weeks autumn through spring; none or minimal in summer | Pet-safe |
| San Jose Hesper Palm | Direct sun (at least 4-6 hours) | Every 2–3 weeks during growth; monthly or less when established | Pet-safe |
| San Jose Hesper Palm | Direct sun (at least 4-6 hours) | When the top 5-7 cm of soil is dry, roughly every 10-14 days in the growing season; every 3-4 weeks in winter | Pet-safe |
| San Pedro Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, every 7-10 days in summer; once every 3-5 weeks in winter | Toxic to pets |
| Sand Couch Grass | Direct sun (at least 4-6 hours) | Rarely — established plants rely on rainfall and groundwater | Pet-safe |
| Sand Crocus | Direct sun (at least 4-6 hours) | Water sparingly; keep dry in summer | Toxic to pets |
| Sand Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in the growing season; once every 4-6 weeks in winter | Pet-safe |
| Sand Lovegrass | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 10-14 days | Pet-safe |
| Sand Phlox | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; drought-tolerant | Pet-safe |
| Sand Pink | Direct sun (at least 4-6 hours) | Low; water only when soil is completely dry, roughly every 2–3 weeks in the growing season | Mildly toxic to pets |
| Sand Reed | Direct sun (at least 4-6 hours) | Rarely — depends on deep soil moisture in sand | Pet-safe |
| Sand Rose | Bright indirect light (just back from a sunny window) | When the top 2–3 cm of soil is dry, roughly every 10–14 days in summer and every 3–4 weeks in winter | Mildly toxic to pets |
| Sand Sedge | Direct sun (at least 4-6 hours) | Very infrequent — drought-adapted | Pet-safe |
| Sander's Maxillaria | Bright indirect light (just back from a sunny window) | Every 4–6 days year-round; never allow to fully dry out | Pet-safe |
| Sander's Maxillaria | Bright indirect light (just back from a sunny window) | When the top 2 cm of the mix feels dry, roughly every 5-7 days | Pet-safe |
| Sanders Blue Spruce | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply weekly while establishing, then during dry periods | Mildly toxic to pets |
| Sandpaper verbena | Direct sun (at least 4-6 hours) | Every 5–7 days once established; more frequently in extreme heat | Mildly toxic to pets |
| Sandstone Cycad | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in active growth; monthly in winter | Toxic to pets |
| Sandy Sulcorebutia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; very sparingly or not at all in winter | Pet-safe |
| Sanguisorba 'Tanna' | Direct sun (at least 4-6 hours) | Keep soil moist but not waterlogged; water every 4-7 days in dry weather | Pet-safe |
| Sanguisorba canadensis | Direct sun (at least 4-6 hours) | Keep consistently moist; water 2-3 times weekly in dry spells | Mildly toxic to pets |
| Sanguisorba menziesii | Direct sun (at least 4-6 hours) | Keep soil moist; water every 3-5 days in dry spells | Pet-safe |
| Sanguisorba obtusa | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply once or twice a week in dry spells | Mildly toxic to pets |
| Sanguisorba officinalis | Direct sun (at least 4-6 hours) | Keep soil moist; water every 4-7 days in dry spells | Pet-safe |
| Santa Barbara Ceanothus | Direct sun (at least 4-6 hours) | Every 7-10 days during the first growing season; established plants are very drought-tolerant and need watering only during prolonged drought | Mildly toxic to pets |
| Santa Barbara Island Liveforever | Direct sun (at least 4-6 hours) | Every 1–2 weeks in the cool season (October–March); none from June–September | Pet-safe |
| Santa Rita Prickly Pear | Direct sun (at least 4-6 hours) | Every 2-3 weeks in spring/summer; once every 4-6 weeks in autumn; once monthly or less in winter | Mildly toxic to pets |
| Saphyr Rouge Firethorn | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Sapphire Blue Oat Grass | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then occasionally | Mildly toxic to pets |
| Sarcochilus ceciliae | Bright indirect light (just back from a sunny window) | Water every 2-4 days in growth, allowing the medium to approach dryness between waterings | Pet-safe |
| Sarcochilus falcatus | Bright indirect light (just back from a sunny window) | Water every 2-3 days, keeping the roots moist but well aired | Pet-safe |
| Sarcochilus hartmannii | Bright indirect light (just back from a sunny window) | Water every 2-4 days, keeping the medium damp but never waterlogged | Pet-safe |
| Sarcococca confusa | Low light (north window or shaded room) | Water regularly to establish; afterwards every 7-14 days during dry spells | Mildly toxic to pets |
| Sarcococca Humilis | Low light (north window or shaded room) | Water regularly to establish; thereafter every 7-14 days in prolonged dry spells | Mildly toxic to pets |
| Sardinian Glory of the Snow | Bright indirect light (just back from a sunny window) | Low; natural rainfall sufficient in most temperate climates | Mildly toxic to pets |
| Sardinian Glory of the Snow | Bright indirect light (just back from a sunny window) | Relies on natural rainfall during spring; water only if conditions are exceptionally dry | Toxic to pets |
| Sargent Cherry Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil starts to dry, often daily in summer | Toxic to pets |
| Sargent's quince | Bright indirect light (just back from a sunny window) | Weekly when establishing; drought-tolerant once established | Mildly toxic to pets |
| Sarracenia oreophila | Direct sun (at least 4-6 hours) | Keep soil constantly wet; stand in 1-3 cm of water during the growing season | Mildly toxic to pets |
| Sasanqua Camellia | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply once or twice weekly in the growing season, more in heat | Pet-safe |
| Sasanqua Camellia 'Yuletide' | Bright indirect light (just back from a sunny window) | About weekly, more in summer heat; water when the top 3-5 cm of soil is dry | Pet-safe |
| Satinleaf | Direct sun (at least 4-6 hours) | Weekly during establishment; every 10–14 days once established; drought-tolerant when mature | Mildly toxic to pets |
| Satomi Dogwood | Bright indirect light (just back from a sunny window) | Weekly during the growing season; every 2 weeks once fully established | Mildly toxic to pets |
| Satsuki Azalea | Bright indirect light (just back from a sunny window) | Keep evenly moist — water when the surface just begins to dry, often daily in heat | Toxic to pets |
| Saucer Magnolia | Direct sun (at least 4-6 hours) | Weekly while establishing, then during dry spells | Pet-safe |
| Saucer Magnolia | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 10–14 days once mature in dry spells | Pet-safe |
| Saucer Plant | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is fully dry, roughly every 10-14 days in growth | Mildly toxic to pets |
| Saw-wort | Bright indirect light (just back from a sunny window) | Low once established | Mildly toxic to pets |
| Sawara Cypress | Direct sun (at least 4-6 hours) | When the top 2 cm of soil starts to dry, often daily in summer heat | Mildly toxic to pets |
| Sawtooth Sunflower | Direct sun (at least 4-6 hours) | Weekly when young; every 1-2 weeks when established | Pet-safe |
| Sawtooth Venus flytrap | Direct sun (at least 4-6 hours) | Keep continuously moist via the tray method | Pet-safe |
| Scabiosa columbaria 'Butterfly Blue' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries; about weekly in the growing season | Pet-safe |
| Scabrosa Rugosa Rose | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant afterwards | Pet-safe |
| Scaly Blazing Star | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought | Pet-safe |
| Scaly Male Fern | Low light (north window or shaded room) | Keep soil moist; water in dry spells, especially while establishing | Mildly toxic to pets |
| Scaly-Stemmed Holly Fern | Low light (north window or shaded room) | Every 5–8 days in growing season, every 10–14 days in winter | Pet-safe |
| Scaped Bergeranthus | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 10-14 days in summer; every 3-4 weeks in winter | Mildly toxic to pets |
| Scarlet Ball Cactus | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil is dry, every 7-10 days in spring and summer; every 3-5 weeks in autumn; very sparingly in winter | Pet-safe |
| Scarlet Bee Balm | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; often twice weekly in summer heat | Mildly toxic to pets |
| Scarlet Bidi-Bidi | Direct sun (at least 4-6 hours) | Fortnightly once established; drought-tolerant | Pet-safe |
| Scarlet bugler | Direct sun (at least 4-6 hours) | Every 10–14 days once established; minimal supplemental water needed | Mildly toxic to pets |
| Scarlet Cleistocactus | Bright indirect light (just back from a sunny window) | When the soil is dry, about every 7-10 days in summer; sparing in winter | Pet-safe |
| Scarlet Dahlia | Direct sun (at least 4-6 hours) | 2–3 times per week during active growth | Mildly toxic to pets |
| Scarlet Freesia | Direct sun (at least 4-6 hours) | Low to moderate during active growth; dry during summer dormancy | Pet-safe |
| Scarlet Giant Hyssop | Direct sun (at least 4-6 hours) | Every 7–10 days until established; every 14 days or less once established | Pet-safe |
| Scarlet Ginger Lily | Bright indirect light (just back from a sunny window) | Frequently during the growing season; reduce sharply in winter | Mildly toxic to pets |
| Scarlet Ginger Lily | Bright indirect light (just back from a sunny window) | Keep soil consistently moist during active growth, watering roughly every 4-6 days | Pet-safe |
| Scarlet Leucothoe | Medium indirect light (a couple of metres from a window) | Regular; maintain consistent moisture | Toxic to pets |
| Scarlet Maxillaria | Bright indirect light (just back from a sunny window) | Every 2–3 days in growth, reduce slightly in winter | Pet-safe |
| Scarlet Sage | Direct sun (at least 4-6 hours) | Every 3–5 days; keep evenly moist | Mildly toxic to pets |
| Scarlet Sundew | Direct sun (at least 4-6 hours) | Tray method in winter–spring; reduce or cease in summer dormancy | Mildly toxic to pets |
| Scepter'd Isle Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat, sandy soil or containers | Pet-safe |
| Schaefer's Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in autumn–spring growing season; once per month or less in summer | Toxic to pets |
| Schied's Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 6-8 weeks in winter | Pet-safe |
| Schizanthus pinnatus 'Angel Wings' | Bright indirect light (just back from a sunny window) | When the top 2 cm of soil is just drying, roughly every 3-5 days | Mildly toxic to pets |
| Schlim's Phragmipedium | Bright indirect light (just back from a sunny window) | Keep the medium consistently moist — water when the top 1-2 cm shows any drying | Pet-safe |
| Schmitz's Cycad | Bright indirect light (just back from a sunny window) | Every 1–2 weeks in growing season; every 3–4 weeks in winter | Toxic to pets |
| Schoenoplectus tabernaemontani 'Albescens' | Direct sun (at least 4-6 hours) | Keep permanently wet; never let the crown dry out | Mildly toxic to pets |
| Schoenoplectus tabernaemontani 'Zebrinus' | Direct sun (at least 4-6 hours) | Constantly wet; shallow margin | Mildly toxic to pets |
| Schott's Hechtia | Direct sun (at least 4-6 hours) | Only when the mix is completely dry, roughly every 14-21 days in summer; monthly or less in winter | Mildly toxic to pets |
| Schwantes' Living Stone | Direct sun (at least 4-6 hours) | Every 10-21 days during the active autumn-to-spring period; none in summer | Pet-safe |
| Schwantes' Living Stones | Direct sun (at least 4-6 hours) | Every 3–4 weeks in autumn; withhold in summer and winter | Pet-safe |
| Schwantesia pillansii | Direct sun (at least 4-6 hours) | Only when soil is completely dry, roughly every 12-16 days in growth; keep nearly dry when dormant | Mildly toxic to pets |
| Sciadopitys 'Ossorio Gold' | Bright indirect light (just back from a sunny window) | Keep evenly moist; deep weekly watering while establishing, more during heat or drought | Mildly toxic to pets |
| Sciadopitys 'Wintergreen' | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water deeply weekly in the first 2-3 years, more in heat | Mildly toxic to pets |
| Scilla siberica | Direct sun (at least 4-6 hours) | Rainfall in most settings; rarely needs watering | Mildly toxic to pets |
| Scirpus lacustris | Direct sun (at least 4-6 hours) | Constantly wet; shallow to moderately deep water | Mildly toxic to pets |
| Scot's Maidenhair Spleenwort | Medium indirect light (a couple of metres from a window) | Keep the gritty mix lightly and evenly moist; water when the surface starts to dry | Pet-safe |
| Scots Pine | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil begins to dry, every few days in summer | Mildly toxic to pets |
| Scottish Heath | Bright indirect light (just back from a sunny window) | Moderate — water during dry spells | Mildly toxic to pets |
| Scrub Palmetto | Direct sun (at least 4-6 hours) | Rarely after establishment — every 3–6 weeks in extended dry spells | Pet-safe |
| Scurfy Laelia | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; once every 2–3 weeks during summer dry rest | Pet-safe |
| Sea Heath | Direct sun (at least 4-6 hours) | Very low; drought-tolerant once established | Mildly toxic to pets |
| Sea Holly | Direct sun (at least 4-6 hours) | Water occasionally while establishing, then rarely once mature | Mildly toxic to pets |
| Sea Knotgrass | Direct sun (at least 4-6 hours) | Very low; exceptionally drought-tolerant | Mildly toxic to pets |
| Sea Lettuce | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in winter (active growth); monthly or less in summer (dormancy) | Pet-safe |
| Sea Mouse-ear | Direct sun (at least 4-6 hours) | Minimal; rely on rainfall in outdoor settings | Mildly toxic to pets |
| Sea Purslane Sun Rose | Direct sun (at least 4-6 hours) | Very low — drought-tolerant once established; water sparingly in the first year only | Mildly toxic to pets |
| Sea Sandwort | Direct sun (at least 4-6 hours) | Infrequently — allow soil to dry between waterings | Pet-safe |
| Sea Spleenwort | Medium indirect light (a couple of metres from a window) | When the top 1–2 cm of growing medium feels dry | Pet-safe |
| Sea Spurge | Direct sun (at least 4-6 hours) | Sparingly — very drought-tolerant | Toxic to pets |
| Sea Stock | Direct sun (at least 4-6 hours) | Weekly during active growth (allow surface to dry slightly between waterings) | Pet-safe |
| Sea Stork's Bill | Direct sun (at least 4-6 hours) | Water sparingly; this species is adapted to dry, free-draining coastal soils | Mildly toxic to pets |
| Sea Thrift | Direct sun (at least 4-6 hours) | Every 10–14 days; drought-tolerant once established | Pet-safe |
| Sea Urchin Copiapoa | Direct sun (at least 4-6 hours) | Every 14-21 days in summer; once a month or completely dry in winter | Pet-safe |
| Seabeach Sandwort | Direct sun (at least 4-6 hours) | Infrequently — highly drought-tolerant once established | Pet-safe |
| Sedum 'Autumn Joy' | Direct sun (at least 4-6 hours) | When soil is dry several centimeters down, roughly every 10-14 days | Pet-safe |
| Sedum 'Matrona' | Direct sun (at least 4-6 hours) | When soil is dry a few centimeters down, roughly every 10-14 days | Pet-safe |
| Sedum burrito | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 1-2 weeks in summer | Pet-safe |
| Sedum clavatum | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-2 weeks in summer | Pet-safe |
| Sedum dasyphyllum | Direct sun (at least 4-6 hours) | Every 1-2 weeks when soil is fully dry in growth; sparingly in winter | Pet-safe |
| Sedum spectabile 'Iceberg' | Direct sun (at least 4-6 hours) | When soil is dry a few centimeters down, about every 10-14 days | Pet-safe |
| Sedum telephium 'Purple Emperor' | Direct sun (at least 4-6 hours) | When soil is dry a few centimeters down, about every 10-14 days | Pet-safe |
| Seigen Japanese Maple | Bright indirect light (just back from a sunny window) | Keep evenly moist; often daily through summer | Mildly toxic to pets |
| Sekete's Restrepia | Bright indirect light (just back from a sunny window) | Every 2-4 days; keep evenly moist | Pet-safe |
| Sellow's Sinningia | Bright indirect light (just back from a sunny window) | Moderate during growth; none during dormancy | Pet-safe |
| Sempervivum 'Black' | Direct sun (at least 4-6 hours) | When soil is fully dry, every 10-14 days in growth; very little in winter | Pet-safe |
| Sempervivum 'Commander Hay' | Direct sun (at least 4-6 hours) | Every 2-3 weeks when fully dry in growth; minimal in winter | Pet-safe |
| Sempervivum 'Emerald Empress' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-2 weeks in summer, far less if grown outdoors in the ground | Pet-safe |
| Sempervivum 'Killer' | Direct sun (at least 4-6 hours) | Every 2-3 weeks when soil is fully dry in growth; almost none in winter | Pet-safe |
| Sempervivum 'Oddity' | Direct sun (at least 4-6 hours) | When the soil is fully dry, sparingly; roughly every 2 weeks in summer and minimal in winter | Pet-safe |
| Sempervivum 'Pacific Blue Ice' | Direct sun (at least 4-6 hours) | Every 2-3 weeks when soil is fully dry in growth; minimal in winter | Pet-safe |
| Sempervivum 'Red Lion' | Direct sun (at least 4-6 hours) | Every 2-3 weeks when soil is fully dry in growth; almost none in winter | Pet-safe |
| Sempervivum 'Reinhard' | Direct sun (at least 4-6 hours) | Every 2-3 weeks when fully dry in growth; minimal in winter | Pet-safe |
| Sempervivum calcareum | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth, only when the soil is fully dry; little to none in winter | Pet-safe |
| Sempervivum heuffelii | Direct sun (at least 4-6 hours) | When the soil is fully dry, sparingly; roughly every 2 weeks in summer and very little in winter | Pet-safe |
| Sempervivum montanum | Direct sun (at least 4-6 hours) | Every 2-3 weeks when soil is fully dry in growth; keep nearly dry in winter | Pet-safe |
| Senecio macroglossus | Bright indirect light (just back from a sunny window) | When the soil is nearly dry, roughly every 10-14 days; less in winter | Toxic to pets |
| Senecio macroglossus 'Variegatus' | Bright indirect light (just back from a sunny window) | When the soil is nearly dry, roughly every 10-14 days; less in winter | Toxic to pets |
| Senegal Date Palm | Direct sun (at least 4-6 hours) | Water deeply every 7-14 days in active growth; more drought-tolerant once established | Pet-safe |
| Senita Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month or less in winter | Pet-safe |
| Sequoia 'Adpressa' | Bright indirect light (just back from a sunny window) | When the top few centimetres of soil dry; keep consistently moist, every 5-10 days | Mildly toxic to pets |
| Serbian Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing in the first two years; established trees rely on rainfall except in prolonged drought | Mildly toxic to pets |
| Serbian Spruce 'Pendula' | Direct sun (at least 4-6 hours) | Every 7-10 days for the first two years; thereafter mostly rainfall-dependent except in drought | Mildly toxic to pets |
| Serra Bromeliad | Bright indirect light (just back from a sunny window) | Occasional; drought-tolerant | Mildly toxic to pets |
| Serrated Enkianthus | Bright indirect light (just back from a sunny window) | Regular — even moisture throughout growing season | Toxic to pets |
| Sesse's Sage | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; monthly in winter | Mildly toxic to pets |
| Sessile-leaved Bellwort | Medium indirect light (a couple of metres from a window) | Once or twice per week during the growing season; minimal watering needed once the plant enters summer dormancy. | Mildly toxic to pets |
| Shadow Adromischus | Medium indirect light (a couple of metres from a window) | Every 2–3 weeks in the active season; monthly in winter | Pet-safe |
| Shady Sage | Bright indirect light (just back from a sunny window) | Allow soil to dry between waterings | Pet-safe |
| Shagbark manzanita | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; more frequent during the first 2 years | Pet-safe |
| Shaggy Trichodiadema | Direct sun (at least 4-6 hours) | When soil is completely dry, approximately every 10-14 days during winter-spring growth period; very sparingly (once monthly) in summer dormancy | Pet-safe |
| Shallon | Medium indirect light (a couple of metres from a window) | Moderate; drought-tolerant once established | Mildly toxic to pets |
| Shand's Gibbaeum | Direct sun (at least 4-6 hours) | Every 2–4 weeks during active growth (autumn and spring); withheld in summer dormancy and reduced to once monthly or less in winter | Pet-safe |
| Shark Teeth Venus flytrap | Direct sun (at least 4-6 hours) | Continuously moist via tray watering; slightly drier in winter | Pet-safe |
| Sharp-fruited Abutilon | Direct sun (at least 4-6 hours) | Every 7–10 days when young; fortnightly once established | Pet-safe |
| Sharp-lobed Hepatica | Medium indirect light (a couple of metres from a window) | Every 5–7 days in spring; reduced to every 10–14 days in summer | Mildly toxic to pets |
| Sharp-Lobed Shield Fern | Medium indirect light (a couple of metres from a window) | Every 7–10 days; reduce in winter | Pet-safe |
| Sharp-petaled Schwantesia | Direct sun (at least 4-6 hours) | Every 10-14 days during autumn and winter growth; once a month in spring; none or minimal in summer | Mildly toxic to pets |
| Sharp-tipped Lepanthes | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; keep roots consistently moist | Pet-safe |
| Shasta daisy | Direct sun (at least 4-6 hours) | Every 5–7 days in summer; less frequently once established | Mildly toxic to pets |
| sheep's fescue | Direct sun (at least 4-6 hours) | Very low; once established, relies on natural rainfall in temperate climates; water monthly if needed during prolonged drought | Pet-safe |
| Sheep's Fescue | Direct sun (at least 4-6 hours) | Established plants are very drought-tolerant; water only during severe prolonged drought, roughly every 14-21 days in dry conditions | Pet-safe |
| Sheerwater Seedling rowan | Direct sun (at least 4-6 hours) | Regular through spring and summer for the first 2 years; minimal once established | Mildly toxic to pets |
| Shenandoah Switch Grass | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water deeply every 1-2 weeks while young | Mildly toxic to pets |
| Shield Sundew | Direct sun (at least 4-6 hours) | Tray-water during active growth (autumn–spring); completely dry in summer. | Pet-safe |
| Shimpaku Juniper | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is just dry, often daily in summer heat | Toxic to pets |
| Shining Cinquefoil | Direct sun (at least 4-6 hours) | Every 10–14 days during active growth; very sparsely in winter | Pet-safe |
| Shining Cranesbill | Bright indirect light (just back from a sunny window) | Low; water only in prolonged drought | Pet-safe |
| Shining fetterbush | Bright indirect light (just back from a sunny window) | Consistently moist to wet — do not allow prolonged drought | Toxic to pets |
| Shining Fuchsia | Bright indirect light (just back from a sunny window) | Moderate during growth; minimal in winter | Pet-safe |
| Shining Pondweed | Direct sun (at least 4-6 hours) | Fully submerged — permanently aquatic; water is the growing medium, not an irrigation schedule | Pet-safe |
| Shining Sundew | Bright indirect light (just back from a sunny window) | Tray method — keep 1 cm of pure water at all times | Pet-safe |
| Shohin Japanese Maple | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; often daily in summer heat | Mildly toxic to pets |
| Shore Pine | Direct sun (at least 4-6 hours) | When the top 2-3 cm of the mix is dry, often daily in summer heat and every 3-5 days in cool weather | Pet-safe |
| Short-Frond Lady Fern | Low light (north window or shaded room) | Every 2–3 days; keep consistently moist | Pet-safe |
| Short-Leaved Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 1-2 weeks in summer | Toxic to pets |
| Short-Sepalled Lewisia | Direct sun (at least 4-6 hours) | Moderate in spring; bone-dry in summer dormancy | Mildly toxic to pets |
| Short-stalk Sophronitis | Bright indirect light (just back from a sunny window) | When the bark surface dries, roughly every 5-7 days in summer; every 10-14 days in winter | Pet-safe |
| Short-stemmed Monanthes | Bright indirect light (just back from a sunny window) | Every 2–4 weeks in growing season; monthly or less in winter | Mildly toxic to pets |
| Short-stemmed Restrepia | Medium indirect light (a couple of metres from a window) | Every 2–4 days; medium kept evenly moist | Pet-safe |
| Showy Autumn Crocus | Bright indirect light (just back from a sunny window) | Relies on natural rainfall when established; no summer irrigation | Toxic to pets |
| Showy Autumn Crocus | Bright indirect light (just back from a sunny window) | Relies on natural rainfall; rarely needs supplementary watering in the garden | Toxic to pets |
| Showy Border Forsythia | Direct sun (at least 4-6 hours) | Every 7-14 days during dry spells; very drought-tolerant once established | Pet-safe |
| Showy Cranesbill | Bright indirect light (just back from a sunny window) | Weekly during spring and summer; minimal in autumn and winter | Pet-safe |
| Showy Disocactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, approximately every 7-10 days in spring and summer; reduce to every 3-4 weeks in winter | Pet-safe |
| Showy Goldenrod | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water in extended dry spells only | Pet-safe |
| Showy Japanese Lily | Bright indirect light (just back from a sunny window) | When top 2–3 cm of soil is dry | Toxic to pets |
| Showy Laelia | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; once every 2–4 weeks during dry rest | Pet-safe |
| Showy Milkweed | Direct sun (at least 4-6 hours) | Water weekly the first season; once established water deeply only during prolonged drought | Toxic to pets |
| Showy Stonecrop | Direct sun (at least 4-6 hours) | Every 1–2 weeks in dry spells; drought-tolerant once established | Mildly toxic to pets |
| Shrimp Plant | Bright indirect light (just back from a sunny window) | When the top 2–3 cm (1 in) of compost dries out | Pet-safe |
| Shrubby Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks from late summer through early spring; completely dry in June–August | Pet-safe |
| Shrubby Indian Mallow | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; monthly or as needed in winter | Pet-safe |
| Shrubby Nemesia | Direct sun (at least 4-6 hours) | Water when the top 2–3 cm of soil is dry | Mildly toxic to pets |
| Shrubby St John's Wort | Bright indirect light (just back from a sunny window) | Drought-tolerant once established; water through the first season | Toxic to pets |
| Siamese Sago Palm | Bright indirect light (just back from a sunny window) | Every 14–21 days in active growth; minimal in winter | Toxic to pets |
| Siberian Bugloss 'Hadspen Cream' | Medium indirect light (a couple of metres from a window) | Every 5-7 days during the growing season; reduce in winter | Pet-safe |
| Siberian dogwood | Bright indirect light (just back from a sunny window) | Weekly when establishing; tolerates wet conditions long-term | Mildly toxic to pets |
| Siberian Elm Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil dries, typically daily in summer | Mildly toxic to pets |
| Siberian Fir | Direct sun (at least 4-6 hours) | Moderate; relies on snowmelt and seasonal rain | Pet-safe |
| Siberian Lady Fern | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water when the top 2 cm begin to dry, roughly weekly in dry weather | Mildly toxic to pets |
| Siberian larkspur | Direct sun (at least 4-6 hours) | Regular — water 2–3 times per week; reduce to weekly once established in cool weather | Toxic to pets |
| Sichuan Arborvitae | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Sichuan Cycad | Bright indirect light (just back from a sunny window) | Every 10–14 days in summer; every 3–4 weeks in winter | Toxic to pets |
| Sickle-leaved Hare's-ear | Direct sun (at least 4-6 hours) | Every 10–14 days, allowing soil to dry between waterings | Mildly toxic to pets |
| Side Oats Grama | Direct sun (at least 4-6 hours) | Water to establish, then only in extreme drought | Mildly toxic to pets |
| Sieber's Crocus | Direct sun (at least 4-6 hours) | Low — water at planting, then rely on rainfall during active growth; keep dry in summer dormancy | Mildly toxic to pets |
| Sieber's Crocus | Direct sun (at least 4-6 hours) | Rainfall typically sufficient; supplement with light watering weekly only during prolonged dry spells in the growing season | Mildly toxic to pets |
| Siebold's Magnolia | Bright indirect light (just back from a sunny window) | Weekly throughout the growing season; reduce in winter | Pet-safe |
| Sierra Cliff Brake Fern | Bright indirect light (just back from a sunny window) | When the soil is completely dry, roughly every 10-21 days depending on season and environment | Pet-safe |
| Sierra Juniper | Direct sun (at least 4-6 hours) | When the soil has begun to dry; lean toward the dry side | Mildly toxic to pets |
| Sierra Leucothoe | Medium indirect light (a couple of metres from a window) | Regularly; do not allow to dry out between waterings | Toxic to pets |
| Sikkim Banana | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during active growth | Pet-safe |
| Sikkim Larch | Direct sun (at least 4-6 hours) | Weekly during establishment, less once established | Pet-safe |
| Silberfeder Silver Feather Grass | Direct sun (at least 4-6 hours) | Weekly through the first season, then only in extended drought | Mildly toxic to pets |
| Silk Floss Tree | Direct sun (at least 4-6 hours) | Every 7–14 days in summer; every 3–5 weeks in winter | Mildly toxic to pets |
| Silky Aster | Direct sun (at least 4-6 hours) | Low — drought tolerant | Pet-safe |
| Silky Petrocosmea | Medium indirect light (a couple of metres from a window) | Every 10–14 days in growth; very sparingly in winter | Pet-safe |
| Silky Prairie Clover | Direct sun (at least 4-6 hours) | Very low — highly drought-tolerant; avoid overwatering | Mildly toxic to pets |
| Silver Air Plant | Bright indirect light (just back from a sunny window) | Soak for 20–30 minutes twice a week; mist 2–3 times weekly | Pet-safe |
| Silver Ball Cactus | Bright indirect light (just back from a sunny window) | When the top of the mix is dry, roughly every 7-10 days in summer; none in winter | Pet-safe |
| Silver Ball Cactus | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, every 10-14 days in summer; every 4-6 weeks in autumn; once monthly or less in winter | Pet-safe |
| Silver Ball Notocactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; once a month or less in winter | Pet-safe |
| Silver Ball Notocactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, approximately every 10-14 days in summer; sparingly once every 4-6 weeks in winter | Pet-safe |
| Silver Crown | Bright indirect light (just back from a sunny window) | Every 10–14 days in spring and summer (growing season); every 3–4 weeks in autumn–winter | Toxic to pets |
| Silver Crown Cotyledon | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring/summer; every 4–6 weeks in autumn/winter | Toxic to pets |
| Silver Cup Annual Mallow | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Silver Date Palm | Direct sun (at least 4-6 hours) | Every 7–14 days in summer; every 3–4 weeks in winter | Pet-safe |
| Silver Date Palm | Direct sun (at least 4-6 hours) | Water deeply every 10-14 days in dry periods; largely self-sufficient once established in the ground | Pet-safe |
| Silver Dollar Jade | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Toxic to pets |
| Silver European Fan Palm | Direct sun (at least 4-6 hours) | Water every 14-21 days in dry periods; very drought-tolerant once established in the ground | Pet-safe |
| Silver Feather Grass | Direct sun (at least 4-6 hours) | Water every 7-14 days during the first growing season; established clumps require little supplemental watering | Mildly toxic to pets |
| Silver Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; rainfall-dependent once established | Pet-safe |
| Silver Hechtia | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is completely dry, roughly every 10-14 days in growing season | Mildly toxic to pets |
| Silver Jade Plant | Bright indirect light (just back from a sunny window) | When the top 2-4 cm of soil is dry, roughly every 10-14 days in summer | Toxic to pets |
| Silver Mediterranean Fan Palm | Direct sun (at least 4-6 hours) | Moderate; allow top 3–5 cm to dry between waterings | Pet-safe |
| Silver Mullein | Direct sun (at least 4-6 hours) | Every 2–4 weeks when established; weekly for young transplants | Mildly toxic to pets |
| Silver Pagoda Dogwood | Bright indirect light (just back from a sunny window) | Regular throughout the growing season; do not allow to dry out | Mildly toxic to pets |
| Silver Pink Rock Rose | Direct sun (at least 4-6 hours) | Establish with regular watering in the first season; once established, water only during prolonged drought spells in summer. | Mildly toxic to pets |
| Silver Sage | Direct sun (at least 4-6 hours) | Fortnightly or when soil is dry | Pet-safe |
| Silver Shamrock | Direct sun (at least 4-6 hours) | Water sparingly; allow to dry between waterings | Toxic to pets |
| silver spike grass | Direct sun (at least 4-6 hours) | Weekly in the first season; monthly deep watering once established | Pet-safe |
| Silver Spurflower | Bright indirect light (just back from a sunny window) | Water when the top 2–3 cm of compost is dry, roughly every 6–10 days in the growing season | Mildly toxic to pets |
| Silver Tansy | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; more frequent only when young | Mildly toxic to pets |
| Silver Torch Cactus | Direct sun (at least 4-6 hours) | When the soil is dry, about every 10-14 days in summer; keep dry in winter | Pet-safe |
| Silver Tree Fern | Bright indirect light (just back from a sunny window) | Keep consistently moist; water every 3-5 days in summer, reducing to every 7-10 days in cooler months | Pet-safe |
| Silver Waves Cotyledon | Bright indirect light (just back from a sunny window) | When the soil is almost dry, roughly every 10-14 days in summer | Toxic to pets |
| Silver-edged Primrose | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce in summer dormancy | Mildly toxic to pets |
| Silverberry | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Silvery Glade Fern | Low light (north window or shaded room) | Every 4–6 days in summer, every 8–12 days in winter | Pet-safe |
| Silvery Yarrow | Direct sun (at least 4-6 hours) | Every 10–14 days; very drought-tolerant once established | Mildly toxic to pets |
| Simon Bamboo | Direct sun (at least 4-6 hours) | 2–3 times per week in summer, once per week in winter | Pet-safe |
| Simple-leaf astilbe | Medium indirect light (a couple of metres from a window) | Consistently moist — water 2–3 times per week in dry spells | Pet-safe |
| Simpson's Juttadinteria | Direct sun (at least 4-6 hours) | Every 2–3 days in the active season (autumn and spring); very sparingly in summer | Mildly toxic to pets |
| Simulated Air Plant | Bright indirect light (just back from a sunny window) | Weekly soak of 20–30 minutes | Pet-safe |
| Sinaloa Sage | Bright indirect light (just back from a sunny window) | Weekly in the growing season; allow soil to partially dry between waterings | Mildly toxic to pets |
| Single-Flowered Bladderwort | Bright indirect light (just back from a sunny window) | Keep substrate permanently moist to wet throughout the growing season; reduce to just damp in cooler winter months | Mildly toxic to pets |
| Sinomiyama Toad Lily | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water when the surface begins to dry, often twice weekly in summer | Mildly toxic to pets |
| Sintenis's Rock Rose | Direct sun (at least 4-6 hours) | Deeply once or twice monthly during the first growing season; essentially rain-fed once established in the ground. | Mildly toxic to pets |
| Siskiyou Blue Idaho Fescue | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; deep but infrequent once established | Mildly toxic to pets |
| Siskiyou Lewisia | Bright indirect light (just back from a sunny window) | Regular in spring/summer; very sparing in winter | Mildly toxic to pets |
| Sissinghurst White Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry weather, more in containers | Mildly toxic to pets |
| Skimmia japonica Kew White | Medium indirect light (a couple of metres from a window) | Maintain consistently moist soil; water deeply every 5-7 days in dry weather | Mildly toxic to pets |
| Skimmia japonica Rubella | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water deeply every 5-7 days in dry spells, less in cool months | Mildly toxic to pets |
| Skimmia Pabella | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water deeply every 5-7 days in dry spells | Mildly toxic to pets |
| Skimmia Temptation | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water deeply every 5-7 days during dry periods | Mildly toxic to pets |
| Sky Blue Aster | Direct sun (at least 4-6 hours) | Water to establish, then rarely; very drought-tolerant | Pet-safe |
| Sky Rocket Feather Top | Direct sun (at least 4-6 hours) | Weekly while establishing, then occasional deep watering in drought | Pet-safe |
| Skyrocket Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days when establishing, then occasional deep soaks | Mildly toxic to pets |
| Slack's Sundew | Direct sun (at least 4-6 hours) | Tray-water continuously during active growth; allow tray to dry slightly during the mild winter rest (does not have a hard dormancy). | Pet-safe |
| Slanted Air Plant | Medium indirect light (a couple of metres from a window) | Mist 3–4 times per week; soak in cool water for 15–20 minutes every 5–7 days. | Pet-safe |
| Sleeping Beauty Cymbidium | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth; reduce to every 10–14 days in autumn–winter | Pet-safe |
| Slender Aubrieta | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Mildly toxic to pets |
| Slender Frailea | Bright indirect light (just back from a sunny window) | When the top 3 cm of soil is dry, roughly every 10-14 days in summer | Pet-safe |
| Slender Iceplant | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry completely between waterings | Pet-safe |
| Slender Waterweed | Medium indirect light (a couple of metres from a window) | Fully submerged aquatic; maintain in aquarium or pond water continuously | Pet-safe |
| Slender-Leaved Sundew | Direct sun (at least 4-6 hours) | Keep substrate consistently moist via a shallow tray; refresh water every few days | Pet-safe |
| Slender-lined Living Stones | Direct sun (at least 4-6 hours) | Very infrequent — one or two waterings during the autumn growth window (September–November); completely dry for 7–8 months of the year | Pet-safe |
| Slim-leaved Biarum | Direct sun (at least 4-6 hours) | Water sparingly in autumn and winter; keep completely dry from late spring through summer dormancy | Toxic to pets |
| Slipper Flower | Bright indirect light (just back from a sunny window) | Regularly — keep soil evenly moist, especially in bud and bloom | Mildly toxic to pets |
| Slowmound Mugo Pine | Direct sun (at least 4-6 hours) | Water weekly through the first growing season, then only during extended drought | Mildly toxic to pets |
| Small Grape Hyacinth | Direct sun (at least 4-6 hours) | Rainfall usually sufficient; water once per week only if spring is unusually dry | Toxic to pets |
| Small Japanese Silver Grass | Bright indirect light (just back from a sunny window) | Weekly during the first season; every 10–14 days once established, or as needed during drought. | Mildly toxic to pets |
| Small Scabious | Direct sun (at least 4-6 hours) | Moderate while establishing; reduced once rooted — water when the top few centimetres of soil are dry | Mildly toxic to pets |
| Small-flowered alumroot | Medium indirect light (a couple of metres from a window) | Weekly during the growing season; do not allow to dry out completely | Pet-safe |
| Small-flowered calibrachoa | Direct sun (at least 4-6 hours) | Every 2–3 days in warm weather; weekly when established or in cool periods | Mildly toxic to pets |
| Small-Flowered Cranesbill | Bright indirect light (just back from a sunny window) | Low; water sparingly and only in drought | Pet-safe |
| Small-flowered Pickerelweed | Direct sun (at least 4-6 hours) | Continuously moist to submerged | Pet-safe |
| Small-Flowered Rock Rose | Direct sun (at least 4-6 hours) | Low — establishment watering only | Mildly toxic to pets |
| Small-leaved Fuchsia | Bright indirect light (just back from a sunny window) | Every 5-7 days in the growing season; every 14-21 days in winter | Pet-safe |
| Small-scaled Pink | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to approach dryness between waterings | Mildly toxic to pets |
| Smith's Fairybells | Medium indirect light (a couple of metres from a window) | Weekly during the growing season; reduce in winter dormancy | Mildly toxic to pets |
| Smokebush 'Royal Purple' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry; weekly in the first season, then only in extended drought | Mildly toxic to pets |
| Smooth Arizona Cypress | Direct sun (at least 4-6 hours) | Infrequently; highly drought-tolerant once established | Mildly toxic to pets |
| Smooth Blue Aster | Direct sun (at least 4-6 hours) | Water weekly until established, then sparingly | Pet-safe |
| Smooth Cordgrass | Direct sun (at least 4-6 hours) | Continuous tidal immersion — lower intertidal zone | Pet-safe |
| Smooth Hydrangea 'Incrediball' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, often every 2-4 days in summer | Toxic to pets |
| Smooth Oxeye | Direct sun (at least 4-6 hours) | Every 1-2 weeks | Pet-safe |
| Smooth Solomon's Seal | Medium indirect light (a couple of metres from a window) | Regular; keep soil evenly moist | Mildly toxic to pets |
| Snake Vine | Direct sun (at least 4-6 hours) | Low to moderate; highly drought tolerant once established | Mildly toxic to pets |
| Snake's Head Iris | Direct sun (at least 4-6 hours) | Moderate in autumn to spring; dry in summer | Toxic to pets |
| Snapdragon | Direct sun (at least 4-6 hours) | Weekly watering | Pet-safe |
| Snapdragon 'Madame Butterfly' | Direct sun (at least 4-6 hours) | Keep evenly moist; water about twice a week, adjusting for heat, letting the top of the soil dry first | Pet-safe |
| Snapdragon 'Rocket' | Direct sun (at least 4-6 hours) | Keep evenly moist; water roughly twice a week, more in heat, letting the surface dry between | Pet-safe |
| Snapdragon vine | Bright indirect light (just back from a sunny window) | Water when the top 2–3 cm of soil dries out, roughly every 5–7 days | Pet-safe |
| Sneed's Pincushion | Direct sun (at least 4-6 hours) | When the potting mix is completely dry, roughly every 14-21 days in the growing season; almost none in winter | Pet-safe |
| Sneezeweed 'Moerheim Beauty' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Sneezeweed 'Riverton Beauty' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days during the growing season | Toxic to pets |
| Sneezewort | Direct sun (at least 4-6 hours) | Weekly or more in dry spells; tolerates seasonal moisture | Mildly toxic to pets |
| Snow Crystals Sweet Alyssum | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil feels dry, roughly every 5-7 days in warm weather | Pet-safe |
| Snow Trillium | Medium indirect light (a couple of metres from a window) | Moderate during spring growth; dry summer dormancy | Mildly toxic to pets |
| Snow-in-Summer | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; minimal in winter | Pet-safe |
| Snowball Pincushion | Direct sun (at least 4-6 hours) | When fully dry, about every 10-14 days in summer; keep dry through winter | Pet-safe |
| Snowberry | Bright indirect light (just back from a sunny window) | Regular; keep consistently moist | Mildly toxic to pets |
| Snowberry Heath | Medium indirect light (a couple of metres from a window) | Regularly; maintain consistently moist but not waterlogged soil | Pet-safe |
| Snowdrop Windflower | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Soap Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, every 1-2 weeks in warm growth | Toxic to pets |
| Socotra Begonia | Bright indirect light (just back from a sunny window) | Every 7–10 days during the growing season (autumn–spring); completely dry during summer dormancy | Toxic to pets |
| Soft Draba | Direct sun (at least 4-6 hours) | Very low — keep almost dry in winter | Mildly toxic to pets |
| Soft Shield Fern | Low light (north window or shaded room) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Soft Tree Fern | Medium indirect light (a couple of metres from a window) | Keep the trunk and root zone consistently moist; water into the crown and down the trunk every few days in warm weather | Mildly toxic to pets |
| Soft-leaf Dunce Cap | Bright indirect light (just back from a sunny window) | Approximately every 12–14 days in the growing season; very sparingly in winter dormancy | Pet-safe |
| soft-leaf primulina | Medium indirect light (a couple of metres from a window) | Every 7–12 days in spring–summer; every 14–21 days in winter | Pet-safe |
| Soft-stem Bulrush | Direct sun (at least 4-6 hours) | Permanently aquatic or waterlogged; plant at 0–60 cm (0–24 in) water depth | Pet-safe |
| Solanum crispum 'Glasnevin' | Direct sun (at least 4-6 hours) | Keep evenly moist in the first two seasons; water established plants during prolonged dry spells | Toxic to pets |
| Solanum laxum | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days in growth | Toxic to pets |
| Solanum laxum 'Album' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days in growth | Toxic to pets |
| Solidago 'Fireworks' | Direct sun (at least 4-6 hours) | Water weekly until established, then only in droughts | Mildly toxic to pets |
| Sonoran Dioon | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; every 4–6 weeks or less in winter | Toxic to pets |
| Sonoran Ibervillea | Bright indirect light (just back from a sunny window) | Every 14–21 days in summer; very sparingly in winter | Mildly toxic to pets |
| Sonoran Palmetto | Direct sun (at least 4-6 hours) | When the top 5-6 cm of soil is dry, roughly every 14-21 days in summer | Pet-safe |
| Sooty Coelogyne | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; reduce to every 10–14 days in winter | Pet-safe |
| Sophronitis coccinea | Bright indirect light (just back from a sunny window) | Every 2-4 days; keep evenly moist year-round | Pet-safe |
| Sorbet XP Mix Viola | Bright indirect light (just back from a sunny window) | When the top 1–2 cm of soil begins to dry, roughly every 4–6 days | Mildly toxic to pets |
| Sorbus 'Joseph Rock' | Direct sun (at least 4-6 hours) | Water weekly for the first two seasons; established trees need water only in extended drought | Mildly toxic to pets |
| Sorbus aria | Direct sun (at least 4-6 hours) | Water weekly in the first two growing seasons; established trees are markedly drought-tolerant | Mildly toxic to pets |
| Sorbus hupehensis | Direct sun (at least 4-6 hours) | Water weekly through the first two seasons; established trees are fairly drought-tolerant | Mildly toxic to pets |
| Southern Canna | Direct sun (at least 4-6 hours) | Keep consistently moist to wet; suitable for bog or marginal planting | Pet-safe |
| Southern Cattail | Direct sun (at least 4-6 hours) | Continuously moist to submerged | Pet-safe |
| Southern Heath | Direct sun (at least 4-6 hours) | Water regularly but allow the soil surface to dry slightly between waterings | Pet-safe |
| Southern Japanese Hemlock | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduced in winter | Pet-safe |
| Southern Magnolia | Direct sun (at least 4-6 hours) | Deeply once a week for the first two seasons; established trees need water only in drought | Pet-safe |
| Southern Magnolia 'Little Gem' | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 1-2 weeks in dry weather | Pet-safe |
| Southern Marsh Orchid | Direct sun (at least 4-6 hours) | Consistently moist to wet | Mildly toxic to pets |
| Southern Red Trillium | Medium indirect light (a couple of metres from a window) | Regularly moist in spring; reduce by mid-summer | Mildly toxic to pets |
| Southern Shield Fern | Bright indirect light (just back from a sunny window) | Water when the top 3-4 cm of soil dries out, roughly every 5-10 days in summer; reduce in winter | Mildly toxic to pets |
| Souvenir de la Malmaison Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while establishing; mature plants when the top 5 cm of soil is dry | Pet-safe |
| Spanish Bluebell | Medium indirect light (a couple of metres from a window) | Low to moderate; largely self-sufficient once established | Toxic to pets |
| Spanish Fir | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; minimal once mature | Pet-safe |
| Spanish Gorse | Direct sun (at least 4-6 hours) | Low — water only to establish; drought-tolerant thereafter | Toxic to pets |
| Spanish heath | Direct sun (at least 4-6 hours) | Weekly during establishment; fortnightly in summer once established | Pet-safe |
| Spanish Iris | Direct sun (at least 4-6 hours) | Low to moderate — water during growth; keep dry in summer | Toxic to pets |
| Spanish Juniper | Direct sun (at least 4-6 hours) | Water fortnightly when young; essentially self-sufficient once established | Mildly toxic to pets |
| Spanish love-in-a-mist | Direct sun (at least 4-6 hours) | Weekly during dry periods | Mildly toxic to pets |
| Spanish Moss | Bright indirect light (just back from a sunny window) | Mist 2-4 times a week, or soak 20-30 minutes weekly in dry conditions | Pet-safe |
| Spanish snapdragon | Direct sun (at least 4-6 hours) | Once established, every 7–14 days in summer; rarely in winter | Mildly toxic to pets |
| Sparganium erectum | Direct sun (at least 4-6 hours) | Constantly wet; shallow water or saturated margin | Mildly toxic to pets |
| Spartan Cliff Stonecrop | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; monthly or less in autumn/winter | Mildly toxic to pets |
| Spatterdock | Direct sun (at least 4-6 hours) | Permanently aquatic; plant at 30–120 cm (12–48 in) water depth | Mildly toxic to pets |
| Spatulate Dendrobium | Bright indirect light (just back from a sunny window) | Regularly through warm growth; reduced over a cool, brighter winter rest | Pet-safe |
| Spear Head | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; every 4–5 weeks in autumn and winter | Toxic to pets |
| Spegazzini's Gymnocalycium | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, every 10-14 days in summer; every 4-6 weeks in winter | Pet-safe |
| Spencer Mixed sweet pea | Direct sun (at least 4-6 hours) | Every 5–7 days; keep roots evenly moist | Mildly toxic to pets |
| Spencer Waved sweet pea | Direct sun (at least 4-6 hours) | Every 2–4 days in warm weather; every 5–7 days in cool spells | Toxic to pets |
| Spider Brake Fern | Medium indirect light (a couple of metres from a window) | When the top 2 cm of mix is dry, about every 5-7 days | Pet-safe |
| Spider Iris | Direct sun (at least 4-6 hours) | Moderate in winter growing season; bone dry in summer dormancy | Toxic to pets |
| Spider Milkweed | Direct sun (at least 4-6 hours) | Low; deep watering every 2–4 weeks once established | Toxic to pets |
| Spike Dunce Cap | Direct sun (at least 4-6 hours) | Every 2–4 weeks during the growing season; sparingly in winter (once a month or less) | Pet-safe |
| Spiked Cautleya | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry during the growing season, roughly every 7-10 days; reduce significantly in winter | Mildly toxic to pets |
| Spiked Ginger Lily | Bright indirect light (just back from a sunny window) | Regularly during active growth; sparingly in winter | Mildly toxic to pets |
| Spiked Ginger Lily | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in the growing season; reduce to every 2-3 weeks in winter | Mildly toxic to pets |
| spiked sedge | Bright indirect light (just back from a sunny window) | Moderate; water weekly in dry spells once established | Pet-safe |
| Spiked speedwell | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant once established | Pet-safe |
| Spindle Palm | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in growth | Mildly toxic to pets |
| Spinulose Lady Fern | Low light (north window or shaded room) | 2–3 times per week; keep consistently moist year-round | Pet-safe |
| Spiny Billbergia | Bright indirect light (just back from a sunny window) | Every 10–14 days | Pet-safe |
| Spiny Club Cactus | Direct sun (at least 4-6 hours) | When soil is dry, about every 10-14 days in summer; little to none in winter | Pet-safe |
| Spiny Fuchsia | Direct sun (at least 4-6 hours) | Infrequent — allow soil to dry between waterings | Pet-safe |
| Spiny Germander | Direct sun (at least 4-6 hours) | Very infrequently once established; water lightly only during extreme summer drought | Mildly toxic to pets |
| Spiny Lady Fern | Medium indirect light (a couple of metres from a window) | Twice weekly throughout the growing season | Mildly toxic to pets |
| Spiny Orostachys | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; almost none in winter dormancy | Pet-safe |
| Spiny Racinaea | Bright indirect light (just back from a sunny window) | Mist 3-5 times per week or soak in water for 20-30 minutes 1-2 times per week | Pet-safe |
| Spiny Ruschia | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days in summer; once every 4-6 weeks in winter | Pet-safe |
| Spiny Tree Fern | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days | Pet-safe |
| Spinystar Cactus | Direct sun (at least 4-6 hours) | When the potting mix is completely dry, roughly every 10-14 days in summer; almost none from October to March | Pet-safe |
| Spiraea 'Anthony Waterer' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Spiraea 'Gold Flame' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about once per week | Mildly toxic to pets |
| Spiraea 'Goldflame' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during active growth | Mildly toxic to pets |
| Spiraea 'Grefsheim' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Spiraea 'Little Princess' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about once per week | Mildly toxic to pets |
| Spiraea 'Little Princess' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Spiraea 'Magic Carpet' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Spiraea 'Shirobana' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days once established | Pet-safe |
| Spiraea betulifolia 'Tor' | Direct sun (at least 4-6 hours) | Weekly when young; during dry spells only once established | Mildly toxic to pets |
| Spiraea nipponica 'Snowmound' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, about once per week | Mildly toxic to pets |
| Spiraea prunifolia | Direct sun (at least 4-6 hours) | Weekly while establishing; only in extended dry spells once mature | Mildly toxic to pets |
| Spiraea thunbergii 'Ogon' | Direct sun (at least 4-6 hours) | Weekly while establishing, then only in droughts | Mildly toxic to pets |
| Spiraea x vanhouttei | Direct sun (at least 4-6 hours) | Weekly in the first year; established plants need water only in prolonged drought | Mildly toxic to pets |
| Spiral Aloe | Direct sun (at least 4-6 hours) | When the top few cm dry out in growth, less in dormancy | Toxic to pets |
| Splendid Fuchsia | Bright indirect light (just back from a sunny window) | Regular during growth; reduce in winter | Pet-safe |
| Splitbeard Bluestem | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days | Pet-safe |
| Spoon-leaved Aloinopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks from autumn through early spring; minimal or none June–August | Pet-safe |
| Spoon-leaved Sundew | Direct sun (at least 4-6 hours) | Keep constantly wet; stand in 1-2 cm of water year-round | Mildly toxic to pets |
| Spotted Aichryson | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; once monthly or less in winter | Mildly toxic to pets |
| Spotted Corn Lily | Direct sun (at least 4-6 hours) | Moderate in growth; completely dry in summer dormancy | Mildly toxic to pets |
| Spotted Joe Pye Weed | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water weekly or more in dry spells | Pet-safe |
| Spotted Mandarin | Medium indirect light (a couple of metres from a window) | Regular; keep soil evenly moist | Mildly toxic to pets |
| Spotted Nomocharis | Bright indirect light (just back from a sunny window) | Moderate to high; soil should remain consistently moist | Toxic to pets |
| Spotted Trillium | Medium indirect light (a couple of metres from a window) | Regular during active growth; minimal when dormant | Mildly toxic to pets |
| Spotted Voodoo Lily | Bright indirect light (just back from a sunny window) | Dry during flowering phase; then water when the top 2-3 cm of soil is dry during active leaf growth | Toxic to pets |
| Spotted-foot Stelis | Medium indirect light (a couple of metres from a window) | Every 1–2 days (mounted) or 2–3 times per week (potted) | Pet-safe |
| Spreading Spike Moss | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; check every 2-3 days | Pet-safe |
| Sprengel's Air Plant | Bright indirect light (just back from a sunny window) | Soak weekly; mist 2–3 times per week | Pet-safe |
| Spring Cinquefoil | Direct sun (at least 4-6 hours) | Rarely once established; drought-tolerant | Pet-safe |
| Spring Cinquefoil (Potentilla tabernaemontani) | Direct sun (at least 4-6 hours) | Rarely; drought-tolerant once established | Pet-safe |
| Spring Cream heather | Direct sun (at least 4-6 hours) | Weekly during establishment; less frequent once established | Pet-safe |
| Spring Cyclamen | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry during active growth (autumn through spring); withhold during summer dormancy | Toxic to pets |
| Spring Cyclamen | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil is dry, roughly every 7-10 days during active growth | Toxic to pets |
| Spring Gentian | Direct sun (at least 4-6 hours) | Regular; keep soil evenly moist, never waterlogged | Mildly toxic to pets |
| Spring Meadow Saffron | Direct sun (at least 4-6 hours) | Rainfall-dependent through winter and spring; dry summer rest | Toxic to pets |
| Spring Starflower | Bright indirect light (just back from a sunny window) | Occasional in autumn and spring; dry during summer dormancy | Toxic to pets |
| Spring Symphony Foamflower | Medium indirect light (a couple of metres from a window) | Approximately every 5–7 days; more frequently in heat or drought | Pet-safe |
| Spring Symphony Tiarella | Medium indirect light (a couple of metres from a window) | Keep consistently moist; deep-water once or twice weekly during dry weather | Mildly toxic to pets |
| Springwood White winter heath | Direct sun (at least 4-6 hours) | Weekly for new plantings; established plants tolerate dry spells with watering every 2–3 weeks | Pet-safe |
| Square-stalked St John's-wort | Bright indirect light (just back from a sunny window) | High — keep consistently moist to wet | Toxic to pets |
| Square-stemmed Pelargonium | Direct sun (at least 4-6 hours) | Water very sparingly — every 14-21 days in the growing season; almost none in winter | Toxic to pets |
| Squinancywort | Direct sun (at least 4-6 hours) | Rarely — only during prolonged drought | Mildly toxic to pets |
| St Dabeoc's heath | Direct sun (at least 4-6 hours) | Moderate; water regularly to keep soil evenly moist, especially in the first year | Pet-safe |
| Stachyurus praecox | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil begins to dry, roughly every 5-7 days in summer for younger plants | Mildly toxic to pets |
| Stalked Clivia | Bright indirect light (just back from a sunny window) | Water regularly in spring and summer; reduce significantly in autumn and winter. | Toxic to pets |
| Standishii Yew | Bright indirect light (just back from a sunny window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Star Frailea | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is completely dry, roughly every 10-14 days in summer | Pet-safe |
| Star Jasmine | Bright indirect light (just back from a sunny window) | Water regularly to establish; once mature, water during dry spells when the top few cm of soil dries | Pet-safe |
| Star Magnolia | Direct sun (at least 4-6 hours) | Keep moist while establishing; water deeply weekly in dry spells for the first few years | Pet-safe |
| Star Magnolia 'Royal Star' | Direct sun (at least 4-6 hours) | Weekly while young, then in dry periods | Pet-safe |
| Star of Bethlehem | Bright indirect light (just back from a sunny window) | Relies on natural rainfall; supplement only during extended dry spells in spring | Toxic to pets |
| Star-flowered Solomon's Seal | Medium indirect light (a couple of metres from a window) | 2 times per week during the growing season; reduce in dormancy | Mildly toxic to pets |
| Stardust Ice Plant | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7–14 days in summer; reduce in autumn and maintain nearly dry in winter | Mildly toxic to pets |
| Starflower pincushion | Direct sun (at least 4-6 hours) | Every 6–8 days during active growth | Pet-safe |
| Starry Rosinweed | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Starry Solomon's Seal | Medium indirect light (a couple of metres from a window) | Regular, keeping soil evenly moist | Mildly toxic to pets |
| Statice sea lavender | Direct sun (at least 4-6 hours) | Once weekly; allow the top 2–3 cm of soil to dry between waterings | Pet-safe |
| Steeds Japanese Holly | Direct sun (at least 4-6 hours) | Weekly deep watering while establishing, then every 7-14 days during dry spells | Toxic to pets |
| Steinmann's Rebutia | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 14–21 days in spring and autumn; very little or none in winter | Pet-safe |
| Stem-forming Torch Lily | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days during the growing season | Mildly toxic to pets |
| Stemless African Daisy | Direct sun (at least 4-6 hours) | Every 10–14 days (moderate); reduce in dry periods once established | Mildly toxic to pets |
| Stemless Gentian | Bright indirect light (just back from a sunny window) | Regular, keeping soil evenly moist throughout the growing season | Mildly toxic to pets |
| Stephan's Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks from late August through November (active growth); withheld completely from May to late August | Pet-safe |
| Stewartia monadelpha | Bright indirect light (just back from a sunny window) | Weekly; keep soil consistently moist but well-drained | Pet-safe |
| Stewartia pseudocamellia | Bright indirect light (just back from a sunny window) | Weekly; keep soil consistently moist but never waterlogged | Pet-safe |
| Sticky Jerusalem Sage | Direct sun (at least 4-6 hours) | Once every 2 weeks in summer; suspend watering October–March except in prolonged drought | Mildly toxic to pets |
| Sticky Primrose | Bright indirect light (just back from a sunny window) | Regularly in spring and summer; minimal in winter | Toxic to pets |
| Stiff Goldenrod | Direct sun (at least 4-6 hours) | Highly drought-tolerant; water only in prolonged drought | Pet-safe |
| Stiff Sunflower | Direct sun (at least 4-6 hours) | Every 2-3 weeks once established | Pet-safe |
| Stiff twinspur | Direct sun (at least 4-6 hours) | 2–3 times per week in active growth; once per week when established in cooler weather | Pet-safe |
| Stinking Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist to damp through the growing season; reduce after summer dormancy | Mildly toxic to pets |
| Stock | Direct sun (at least 4-6 hours) | Every 5–7 days; keep evenly moist but not wet | Pet-safe |
| Stoloniferous Sundew | Bright indirect light (just back from a sunny window) | Tray method during winter growing season; completely dry during summer dormancy | Mildly toxic to pets |
| Stone Gate Palm | Direct sun (at least 4-6 hours) | Weekly in summer, fortnightly in winter | Pet-safe |
| Stone Mimicry Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn and spring; almost none in summer (June–August in the Northern Hemisphere) | Mildly toxic to pets |
| Stonecrop 'Autumn Joy' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is fully dry, roughly every 10-14 days; less frequent once established | Pet-safe |
| Stonecrop 'Dragon's Blood' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, roughly every 10-14 days; minimal once established | Pet-safe |
| Stonecrop Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; once a month or less in winter | Pet-safe |
| Stonecrop-leaf Aichryson | Bright indirect light (just back from a sunny window) | Every 10–14 days in the active growing season (autumn to spring); once a month or less in summer | Pet-safe |
| Stratiotes aloides | Direct sun (at least 4-6 hours) | Submerged to surface-floating; keep in still water 0.3-1.5 m deep | Mildly toxic to pets |
| Straw Foxglove | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, about weekly in dry weather | Toxic to pets |
| Straw-red Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established; weekly for new plants | Pet-safe |
| Strawberries and Cream Ribbon Grass | Bright indirect light (just back from a sunny window) | Adaptable; moist soil gives best colour but tolerates drought once established | Mildly toxic to pets |
| Strawberry Begonia | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about every 5-7 days | Pet-safe |
| Strawberry Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Strawberry Foxglove | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water weekly in dry periods | Toxic to pets |
| Stribrny's Saxifrage | Direct sun (at least 4-6 hours) | Water sparingly; keep almost dry in winter | Mildly toxic to pets |
| Stricta Feather Reed Grass | Direct sun (at least 4-6 hours) | Consistently moist; tolerates standing water in spring | Pet-safe |
| Strictus Porcupine Grass | Direct sun (at least 4-6 hours) | Weekly to establish, then during dry spells; benefits from steady moisture | Mildly toxic to pets |
| String Bean Hoya | Bright indirect light (just back from a sunny window) | When the soil is almost fully dry, roughly every 10-14 days | Pet-safe |
| String of needles | Bright indirect light (just back from a sunny window) | When soil is dry, every 10-14 days | Mildly toxic to pets |
| String of Teardrops | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (autumn–spring); once a month or less in summer dormancy | Toxic to pets |
| Stripe It Rich Hakone Grass | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Striped Nananthus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; minimal in summer | Mildly toxic to pets |
| Striped Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in winter (growing season); suspend almost entirely in summer | Toxic to pets |
| Striptease Hosta | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth | Toxic to pets |
| Strobel's Masdevallia | Medium indirect light (a couple of metres from a window) | Water freely when the medium begins to approach dryness, roughly every 1-2 days in summer | Pet-safe |
| Strobilanthes kunthianus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 4-7 days in the growing season | Mildly toxic to pets |
| Subalpine Fir | Direct sun (at least 4-6 hours) | Regular watering during establishment; naturally sustained by snowmelt and high-altitude precipitation | Pet-safe |
| Sublime Slipper Orchid | Medium indirect light (a couple of metres from a window) | When the top of the mix is just barely drying, roughly every 5-7 days | Mildly toxic to pets |
| Succulentum Pachypodium | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; withhold in winter | Toxic to pets |
| Sugar and Spice Tiarella | Medium indirect light (a couple of metres from a window) | Keep consistently moist; deep-water once or twice weekly in dry spells | Mildly toxic to pets |
| Sugarcane Plume Grass | Direct sun (at least 4-6 hours) | Keep evenly moist; water weekly in dry spells, more in containers | Mildly toxic to pets |
| Sulcorebutia rauschii | Direct sun (at least 4-6 hours) | When fully dry in summer, roughly every 12-14 days; keep dry in winter | Pet-safe |
| Sulcorebutia steinbachii | Direct sun (at least 4-6 hours) | When fully dry in summer, roughly every 10-14 days; none in winter | Pet-safe |
| Sulphur Clover | Bright indirect light (just back from a sunny window) | Low to moderate; drought-tolerant once established | Pet-safe |
| Sulphur-Yellow Dyckia | Direct sun (at least 4-6 hours) | Only when the mix is completely dry, roughly every 14-21 days in summer; every 30-45 days in winter | Mildly toxic to pets |
| Sulphureum Epimedium | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 1-2 weeks | Mildly toxic to pets |
| Summer Hyacinth | Direct sun (at least 4-6 hours) | Regular during spring and summer; reduce in autumn and winter | Pet-safe |
| Summer Skies delphinium | Direct sun (at least 4-6 hours) | Regular — deep water 2–3 times per week during growth; reduce to weekly after first bloom | Toxic to pets |
| Summit Sage | Bright indirect light (just back from a sunny window) | Every 10–14 days | Pet-safe |
| Sun Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in the growing season; nearly dry in winter | Pet-safe |
| Sun Cup Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; monthly or less in autumn and winter | Pet-safe |
| Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep constantly moist; water from above or stand in a shallow tray of pure water | Mildly toxic to pets |
| Sun Pitcher Plant | Bright indirect light (just back from a sunny window) | Keep pitchers partially filled with distilled water; water substrate when surface begins to dry, roughly every 3-5 days in warm conditions | Pet-safe |
| Sungold Cypress | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water deeply weekly in the first 2 years, then every 10-14 days in dry spells | Toxic to pets |
| Sunken Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 1–2 days; never allow to dry out completely | Pet-safe |
| Sunningdale Silver Pampas Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; thereafter only in extended drought | Pet-safe |
| Sunrise Succulent | Bright indirect light (just back from a sunny window) | When the top 2–3 cm of soil is dry, roughly every 10–14 days in summer and every 3–5 weeks in winter | Mildly toxic to pets |
| Sunsatia Mango Nemesia | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 4-6 days | Pet-safe |
| Sunsatia Plus Coconut Nemesia | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil or compost is dry, roughly every 4-6 days | Pet-safe |
| Super Silver Chalk Dudleya | Direct sun (at least 4-6 hours) | Fortnightly in autumn and winter (active growth); monthly to none in summer (dormant) | Mildly toxic to pets |
| Superb pink | Direct sun (at least 4-6 hours) | Every 7–10 days; drought-tolerant once established | Mildly toxic to pets |
| Superb Stelis | Medium indirect light (a couple of metres from a window) | Every 2–3 days; mounted plants may need daily watering in summer | Pet-safe |
| Superba Astilbe | Bright indirect light (just back from a sunny window) | Keep soil moist; water when the top 2-3 cm dries, roughly every 4-6 days in summer | Mildly toxic to pets |
| Superba Pubescent Lilac | Direct sun (at least 4-6 hours) | When the top 5 cm of soil feels dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Superba Rodgersia | Medium indirect light (a couple of metres from a window) | Keep consistently moist; water deeply 1-2 times weekly, more in heat | Mildly toxic to pets |
| Susan Magnolia | Direct sun (at least 4-6 hours) | Weekly during establishment (2–3 years); every 10–14 days when mature in dry weather | Mildly toxic to pets |
| Sutherland's Ice Plant | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is completely dry, roughly every 7-14 days in growing season; reduce to monthly in winter | Pet-safe |
| Swamp Azalea | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; in garden settings water every 5-7 days during dry spells | Toxic to pets |
| Swamp Loosestrife | Bright indirect light (just back from a sunny window) | Continuously — requires saturated soil or shallow water | Mildly toxic to pets |
| Swamp Milkweed | Direct sun (at least 4-6 hours) | Keep consistently moist; water during dry spells and never let it dry out for long | Toxic to pets |
| Swamp Rose Mallow | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in summer or more frequently in containers | Pet-safe |
| Swamp Tupelo | Direct sun (at least 4-6 hours) | Constantly moist to permanently flooded | Mildly toxic to pets |
| Sweet alyssum | Bright indirect light (just back from a sunny window) | Every 5–7 days; drought-tolerant once established | Pet-safe |
| Sweet Autumn Clematis | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days once established | Toxic to pets |
| Sweet Autumn Clematis | Direct sun (at least 4-6 hours) | Deeply once a week during the growing season; drought-tolerant once established | Toxic to pets |
| Sweet Azalea | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in the growing season | Toxic to pets |
| Sweet Betsy | Medium indirect light (a couple of metres from a window) | Consistently moist through spring and early summer; reduced moisture acceptable during summer dormancy. | Mildly toxic to pets |
| Sweet Birch | Direct sun (at least 4-6 hours) | Moderate; water deeply during drought; established trees on suitable sites are largely self-sufficient | Pet-safe |
| Sweet Box | Low light (north window or shaded room) | Water regularly while establishing; once settled, every 7-14 days in dry spells | Mildly toxic to pets |
| Sweet Mock Orange | Bright indirect light (just back from a sunny window) | When the top 5 cm of soil feels dry, roughly every 7-14 days | Mildly toxic to pets |
| Sweet pea | Direct sun (at least 4-6 hours) | Weekly deep watering | Toxic to pets |
| Sweet Pea 'Cupani' | Direct sun (at least 4-6 hours) | Every 2-3 days in growth, more in heat; keep soil evenly moist | Mildly toxic to pets |
| Sweet Pea 'Spencer' | Direct sun (at least 4-6 hours) | Every 2-3 days, keeping soil consistently moist | Mildly toxic to pets |
| Sweet Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method: keep 1-3 cm of distilled or rainwater in the saucer continuously during the growing season; reduce to slightly moist in winter | Pet-safe |
| Sweet sultan | Direct sun (at least 4-6 hours) | Every 7–10 days | Pet-safe |
| Sweet Trillium | Low light (north window or shaded room) | Keep soil consistently moist spring through early summer; minimal once dormant | Mildly toxic to pets |
| Sweet violet | Medium indirect light (a couple of metres from a window) | Every 5–7 days; keep evenly moist | Pet-safe |
| Sweet White Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist during spring; reduce after dormancy onset | Mildly toxic to pets |
| Sweet White Violet | Medium indirect light (a couple of metres from a window) | Regular; keep soil consistently moist | Pet-safe |
| Sweet William | Direct sun (at least 4-6 hours) | Every 5–7 days; allow surface to dry slightly between waterings | Mildly toxic to pets |
| Sweetbay Magnolia | Direct sun (at least 4-6 hours) | Keep soil consistently moist; weekly deep watering when young and during dry spells | Pet-safe |
| Sweetbells Leucothoe | Medium indirect light (a couple of metres from a window) | Regularly throughout the growing season; do not allow to dry out | Toxic to pets |
| Sweetbriar Rose | Direct sun (at least 4-6 hours) | Weekly while establishing, then minimal | Pet-safe |
| Swertia-leaf Scaphosepalum | Medium indirect light (a couple of metres from a window) | When the medium surface is barely beginning to dry, roughly every 3-5 days | Pet-safe |
| Swingle's primulina | Medium indirect light (a couple of metres from a window) | Every 8–12 days in spring–summer; every 16–21 days in winter | Pet-safe |
| Swollen-stem Tylecodon | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in the growing season (autumn–spring); once monthly or none in summer | Toxic to pets |
| Sword-Leaved Air Plant | Bright indirect light (just back from a sunny window) | Mist 2-3 times per week or soak 20 minutes weekly | Pet-safe |
| Swordleaf Rush | Direct sun (at least 4-6 hours) | Consistently moist to wet soil; tolerates shallow standing water to 5 cm (2 in) | Pet-safe |
| Sylvester Date Palm | Direct sun (at least 4-6 hours) | Deeply every 7-14 days while establishing, then drought-tolerant | Pet-safe |
| Symphyotrichum laeve 'Bluebird' | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged dry spells once settled | Pet-safe |
| Symphyotrichum novae-angliae 'Andenken an Alma Pötschke' | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water deeply in dry spells, roughly weekly | Pet-safe |
| Symphyotrichum novi-belgii 'Fellowship' | Direct sun (at least 4-6 hours) | Keep soil reliably moist; water deeply, around weekly, never letting roots dry | Pet-safe |
| Symphyotrichum oblongifolium 'Raydon's Favorite' | Direct sun (at least 4-6 hours) | Weekly during the first season; once established, only in prolonged drought | Pet-safe |
| Tailed Aechmea | Bright indirect light (just back from a sunny window) | Every 2–3 weeks (soil); refresh central tank monthly | Pet-safe |
| Tailed Masdevallia | Bright indirect light (just back from a sunny window) | Daily in warm weather; every 3–5 days in cooler months | Pet-safe |
| Taiwan Felt Fern | Bright indirect light (just back from a sunny window) | Every 7-10 days; allow surface to dry between waterings | Pet-safe |
| Taiwan Podocarpus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Tall Bluebells | Bright indirect light (just back from a sunny window) | Water deeply 2–3 times weekly; never allow to dry out in growing season | Pet-safe |
| Tall Coreopsis | Direct sun (at least 4-6 hours) | Low once established; water weekly during the first growing season | Pet-safe |
| Tall Goldenrod | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water only in extended dry spells | Pet-safe |
| Tall Ironweed | Direct sun (at least 4-6 hours) | Keep evenly moist; water weekly in dry spells, more in heat | Mildly toxic to pets |
| Tall Mix pincushion flower | Direct sun (at least 4-6 hours) | Once or twice weekly | Pet-safe |
| Tamarack | Direct sun (at least 4-6 hours) | Regular; tolerates seasonally wet or boggy conditions | Pet-safe |
| Tamarillo | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 4-7 days in warm weather | Toxic to pets |
| Tangerine Beauty Crossvine | Bright indirect light (just back from a sunny window) | Weekly until established; drought-tolerant thereafter | Mildly toxic to pets |
| Tannenbaum Mugo Pine | Direct sun (at least 4-6 hours) | Water weekly the first year to establish, then during prolonged dry spells only | Mildly toxic to pets |
| Tanquana hilmarii | Direct sun (at least 4-6 hours) | Sparing from autumn to spring; withhold in summer | Mildly toxic to pets |
| Tanquana prismatica | Direct sun (at least 4-6 hours) | Sparing in autumn-spring; near-zero in summer | Mildly toxic to pets |
| Taraw Palm | Direct sun (at least 4-6 hours) | Regularly during establishment; moderately once mature | Pet-safe |
| Tartarian Honeysuckle | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days once established | Toxic to pets |
| Tasmanian Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, about every 5-7 days | Pet-safe |
| Tasmanian Tree Fern | Bright indirect light (just back from a sunny window) | Keep consistently moist — water when the top 3-4 cm of soil or fibrous trunk surface feels dry, typically every 3-7 days | Pet-safe |
| Tassel Fern | Low light (north window or shaded room) | When the top 2-3 cm of soil is just dry, roughly every 5-7 days in growth | Pet-safe |
| Tassel Grape Hyacinth | Direct sun (at least 4-6 hours) | Minimal; drought-tolerant once established | Toxic to pets |
| Tassel Grape Hyacinth | Direct sun (at least 4-6 hours) | Once per week during spring growth; very dry during summer dormancy | Toxic to pets |
| Tasteless Stonecrop | Bright indirect light (just back from a sunny window) | Every 14-21 days in spring and summer; monthly or less in winter | Pet-safe |
| Tatei Sun Pitcher | Bright indirect light (just back from a sunny window) | Keep pitchers partially filled with distilled water; moisten the substrate every 3-5 days, ensuring it remains consistently damp without waterlogging | Pet-safe |
| Tatting Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season; reduce in winter | Pet-safe |
| Tawny Living Stones | Direct sun (at least 4-6 hours) | Seasonally — water sparingly in autumn (September–November) during active growth; keep completely dry in winter and summer | Pet-safe |
| Tea Tree Bonsai | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the surface just begins to dry, often every 1-3 days in summer | Mildly toxic to pets |
| Teague's Porroglossum | Medium indirect light (a couple of metres from a window) | Every 2–4 days; allow medium surface to dry slightly between waterings | Pet-safe |
| Teasing Georgia Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season; more in heat | Pet-safe |
| Tellmann's honeysuckle | Medium indirect light (a couple of metres from a window) | Weekly during dry spells; especially important in summer while in active growth | Mildly toxic to pets |
| Telstar Mix China Pink | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| Tenby Daffodil | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry during active growth, roughly every 7-10 days | Toxic to pets |
| Tennessee Coneflower | Direct sun (at least 4-6 hours) | Water to establish, then only during extended drought | Pet-safe |
| Tentacle Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting or continuous humidity; never allow roots to fully dry | Pet-safe |
| Teotl Palo | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; every 4–6 weeks in winter or none | Mildly toxic to pets |
| Tephrocactus | Direct sun (at least 4-6 hours) | When the mix is completely dry, sparingly every 2-3 weeks in summer; keep bone-dry in winter | Mildly toxic to pets |
| Tessellated Colchicum | Direct sun (at least 4-6 hours) | Minimal; water lightly after planting, then rely on rainfall during autumn–spring growth | Toxic to pets |
| Tetragona Aurea Hinoki Cypress | Direct sun (at least 4-6 hours) | Every 5-7 days when young, then when the top few cm of soil dry | Mildly toxic to pets |
| Texas Barrel Cactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Texas Nipple Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-14 days in summer and once every 4-6 weeks in winter | Pet-safe |
| Texas Rainbow Cactus | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month or less in winter | Pet-safe |
| Texas Sage | Direct sun (at least 4-6 hours) | Moderate — water once or twice weekly in the growing season | Pet-safe |
| Thai Mountain Palm | Bright indirect light (just back from a sunny window) | Every 5–7 days in summer, fortnightly in cooler months | Pet-safe |
| Thai Silk California poppy | Direct sun (at least 4-6 hours) | Once weekly during establishment; every 2 weeks once established | Mildly toxic to pets |
| Thai Silk Mix California Poppy | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days once established | Mildly toxic to pets |
| Thalictrum 'Elin' | Bright indirect light (just back from a sunny window) | Keep soil reliably moist; water deeply in dry spells | Mildly toxic to pets |
| Thalictrum aquilegiifolium | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water in dry spells | Mildly toxic to pets |
| Thalictrum delavayi 'Hewitt's Double' | Bright indirect light (just back from a sunny window) | Keep soil consistently moist; water regularly in dry weather, do not let it dry out | Mildly toxic to pets |
| Thalictrum flavum subsp. glaucum | Direct sun (at least 4-6 hours) | Keep soil moist; water deeply in dry weather | Mildly toxic to pets |
| Thalictrum rochebrunianum | Bright indirect light (just back from a sunny window) | About twice a week, keeping soil evenly moist | Toxic to pets |
| The Bride pearlbush | Direct sun (at least 4-6 hours) | Weekly during establishment; once established, every 2–3 weeks or during dry spells | Pet-safe |
| The Fairy Rose | Direct sun (at least 4-6 hours) | Deeply once a week in the growing season, more during heatwaves | Pet-safe |
| The Generous Gardener Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; more during establishment and in heat | Pet-safe |
| The Governor lupine | Direct sun (at least 4-6 hours) | Every 7–10 days; less once established | Toxic to pets |
| The Pilgrim Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; more in heat | Pet-safe |
| The Rocket Ligularia | Medium indirect light (a couple of metres from a window) | Keep soil constantly moist; water deeply 2-3 times weekly in summer, daily in heat or dry spells | Mildly toxic to pets |
| Theresa's Pincushion | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer and once every 6-8 weeks in winter | Pet-safe |
| Therese Bugnet Rose | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant thereafter | Pet-safe |
| Thick-stemmed Aichryson | Bright indirect light (just back from a sunny window) | Every 10–15 days during active growth (spring–summer); very sparingly in winter | Mildly toxic to pets |
| Thimble Cactus | Direct sun (at least 4-6 hours) | When fully dry, roughly every 10-14 days in summer; keep nearly dry in winter | Pet-safe |
| Thin-Leaved Air Plant | Bright indirect light (just back from a sunny window) | 2–3 times per week | Pet-safe |
| Thin-Spiked Air Plant | Bright indirect light (just back from a sunny window) | 2–3 times per week (misting) or weekly soak | Pet-safe |
| Thistle Sage | Direct sun (at least 4-6 hours) | Very infrequent — once established, monthly or less in summer | Pet-safe |
| Thomas Edison Dahlia | Direct sun (at least 4-6 hours) | 2–3 times per week during growing season | Mildly toxic to pets |
| Thorn Apple | Direct sun (at least 4-6 hours) | Moderate, once or twice a week in dry spells | Toxic to pets |
| Thorny Chin Cactus | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in summer; every 5–8 weeks in winter | Pet-safe |
| Thoroughwax | Direct sun (at least 4-6 hours) | Every 5–7 days; allow top inch to partially dry between waterings | Pet-safe |
| Thread-Leaf Air Plant | Bright indirect light (just back from a sunny window) | Mist 3–4 times a week or soak once a week | Pet-safe |
| Thread-Leaved Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week, or soak for 20–30 minutes once a week | Pet-safe |
| Threadleaf Coreopsis | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Threadleaf Sawara Cypress | Direct sun (at least 4-6 hours) | Once per week to every 10 days when the top 2-3 cm of soil is dry; drought-tolerant once established | Toxic to pets |
| Threadleaf Tickseed 'Moonbeam' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days; infrequent once established | Pet-safe |
| Three-awn Trisetella | Medium indirect light (a couple of metres from a window) | When the medium surface just begins to dry, roughly every 3-5 days | Pet-safe |
| Three-Coloured Bladderwort | Bright indirect light (just back from a sunny window) | Keep substrate consistently moist; water tray method year-round | Mildly toxic to pets |
| Three-Leaved Stork's Bill | Direct sun (at least 4-6 hours) | Water moderately in the growing season; keep nearly dry in winter | Mildly toxic to pets |
| Threeleaf Foamflower | Medium indirect light (a couple of metres from a window) | Approximately once or twice per week during the growing season; reduce in winter. | Mildly toxic to pets |
| Thrift | Direct sun (at least 4-6 hours) | Every 7–14 days, allowing soil to dry between waterings | Pet-safe |
| Thunberg Spirea | Direct sun (at least 4-6 hours) | Weekly until established; occasional deep watering thereafter | Pet-safe |
| Thunberg's astilbe | Medium indirect light (a couple of metres from a window) | Regular — every 2–3 days in warm weather; reduce in cool, overcast periods | Pet-safe |
| Thunberg's Cycad | Direct sun (at least 4-6 hours) | Every 14–21 days; drought-tolerant once established | Toxic to pets |
| Thyme-leaved Fuchsia | Medium indirect light (a couple of metres from a window) | Regular — keep soil evenly moist | Pet-safe |
| Thyme-leaved Sandwort | Direct sun (at least 4-6 hours) | Low; water sparingly, allow soil to dry between waterings | Mildly toxic to pets |
| Thyrse Ginger Lily | Medium indirect light (a couple of metres from a window) | Consistently moist through growing season; reduced in dormancy | Mildly toxic to pets |
| Tibetan whitebeam | Direct sun (at least 4-6 hours) | Weekly during establishment; low once mature | Mildly toxic to pets |
| Tiger Aloe | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in active growth, sparingly in summer dormancy and winter | Toxic to pets |
| Tiger Flower | Direct sun (at least 4-6 hours) | Regular watering during the growing season; reduce after flowering; dry storage in winter | Mildly toxic to pets |
| Tiger Lily | Direct sun (at least 4-6 hours) | When top 3 cm of soil is dry | Toxic to pets |
| Tiger Tooth Aloe | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-2 weeks in summer, monthly in winter | Toxic to pets |
| Tilia cordata | Direct sun (at least 4-6 hours) | Water young trees deeply every 7-14 days in dry spells for the first two seasons; established trees are largely self-sufficient | Pet-safe |
| Tilia tomentosa 'Petiolaris' | Direct sun (at least 4-6 hours) | Deep watering every 7-14 days during dry weather for the first two or three seasons; established trees seldom need it | Pet-safe |
| Tillandsia aeranthos | Bright indirect light (just back from a sunny window) | Soak 20-30 minutes weekly | Pet-safe |
| Tillandsia bergeri | Bright indirect light (just back from a sunny window) | Soak 20-30 minutes weekly; mist between soaks in dry air | Pet-safe |
| Tillandsia paleacea | Bright indirect light (just back from a sunny window) | Mist 2-3 times a week, or soak briefly every 1-2 weeks | Pet-safe |
| Tillandsia recurvifolia | Bright indirect light (just back from a sunny window) | Soak 20-30 minutes weekly; mist between soaks if air is dry | Pet-safe |
| Tillandsia tectorum | Bright indirect light (just back from a sunny window) | Mist lightly every 10-14 days; soak only rarely | Pet-safe |
| Tiny Dunce Cap | Direct sun (at least 4-6 hours) | Every 1–2 weeks during active growth; very sparingly in winter dormancy | Pet-safe |
| Tiny Sea Lavender | Direct sun (at least 4-6 hours) | Low — water sparingly, allowing soil to dry completely between sessions | Pet-safe |
| Tiny Stelis | Medium indirect light (a couple of metres from a window) | Every 1–2 days; medium should not dry out completely | Pet-safe |
| Tiny Sun Mammillaria | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 10-14 days in summer and once every 6 weeks in winter | Pet-safe |
| Tiny Sundew | Direct sun (at least 4-6 hours) | Shallow water tray in winter–spring; dry rest in summer | Mildly toxic to pets |
| Tiramisu Heuchera | Bright indirect light (just back from a sunny window) | Keep soil evenly moist; water when the top 2-3 cm is dry, roughly every 5-7 days in summer | Pet-safe |
| Tiraque Sulcorebutia | Direct sun (at least 4-6 hours) | Every 10-14 days in active growth; once a month or less from October to February | Pet-safe |
| Titanopsis Hugo-Schlechteri | Direct sun (at least 4-6 hours) | Mainly in autumn through spring, every 2-3 weeks when the soil is fully dry; sparing in hot summer | Mildly toxic to pets |
| Titanopsis primosii | Direct sun (at least 4-6 hours) | In autumn-spring growth once soil is fully dry; withhold through summer dormancy | Mildly toxic to pets |
| Titanopsis schwantesii | Direct sun (at least 4-6 hours) | During autumn-spring growth when soil is fully dry; near-zero in summer | Mildly toxic to pets |
| Titanotrichum oldhamii | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 4-7 days in growth | Mildly toxic to pets |
| Toad Tree | Direct sun (at least 4-6 hours) | Moderate; water regularly in summer, reduce significantly in winter dormancy | Toxic to pets |
| Toadshade Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist during spring and summer growing season; allow soil to dry slightly after summer dormancy. | Mildly toxic to pets |
| Toffee Twist Sedge | Direct sun (at least 4-6 hours) | Keep evenly moist; water once or twice weekly in heat, less when cool | Mildly toxic to pets |
| Tojen Toad Lily | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water when the surface begins to dry, roughly once or twice a week in summer | Mildly toxic to pets |
| Tom Thumb Cactus | Bright indirect light (just back from a sunny window) | Every 10-14 days in spring/summer; every 3-4 weeks in autumn; once or twice in winter | Mildly toxic to pets |
| Tomaselli's Dioon | Direct sun (at least 4-6 hours) | Every 2–4 weeks in the growing season; every 5–8 weeks or less in winter | Toxic to pets |
| Tompa Norway Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days when establishing; deep watering as the top few cm of soil dry | Pet-safe |
| Tongue Fern | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of medium is dry, roughly every 7-10 days | Pet-safe |
| Tongue Leaf Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in autumn and spring; very sparingly in summer and winter | Mildly toxic to pets |
| Toothed Fly Bush | Direct sun (at least 4-6 hours) | Keep substrate evenly moist; water every 2–4 days with pure water only | Pet-safe |
| Toothed Fuchsia | Bright indirect light (just back from a sunny window) | Regular — keep evenly moist | Pet-safe |
| Toothed Nemesia | Direct sun (at least 4-6 hours) | Water regularly to keep compost evenly moist | Mildly toxic to pets |
| Toothpick plant | Direct sun (at least 4-6 hours) | Every 6–9 days; drought-tolerant when established | Mildly toxic to pets |
| Toothwort | Medium indirect light (a couple of metres from a window) | 2–3 times per week during the brief spring growth period; essentially none during summer dormancy | Pet-safe |
| Top-shaped Living Stones | Direct sun (at least 4-6 hours) | Every 3–4 weeks in autumn; none in summer or winter | Pet-safe |
| Torch Aloe | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | Toxic to pets |
| Tormentil | Bright indirect light (just back from a sunny window) | Moderate; keep soil lightly moist but not wet | Pet-safe |
| Totara | Direct sun (at least 4-6 hours) | When the topsoil dries, weekly while establishing then as needed | Toxic to pets |
| Trachelospermum jasminoides 'Variegatum' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days in growth | Pet-safe |
| Trailing Abutilon | Bright indirect light (just back from a sunny window) | Freely in growth (spring–autumn); sparingly in winter | Mildly toxic to pets |
| Trailing African daisy | Direct sun (at least 4-6 hours) | Once or twice a week during active growth; reduce to once a week or less once established | Pet-safe |
| Trailing Elephant Bush | Bright indirect light (just back from a sunny window) | Every 7–10 days in summer; every 2–3 weeks in winter | Pet-safe |
| Trailing Fuchsia | Bright indirect light (just back from a sunny window) | Every 7-10 days in summer; very sparingly in winter | Pet-safe |
| Trailing Ice Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks (allow soil to dry completely between waterings) | Pet-safe |
| Trailing Iceplant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the growing season; minimal in winter | Mildly toxic to pets |
| Trailing Iceplant Vygie | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is fully dry, roughly every 7-10 days in spring-summer; monthly or less in winter | Pet-safe |
| Trailing Lantana | Direct sun (at least 4-6 hours) | Every 1–2 weeks (drought-tolerant when established) | Toxic to pets |
| Trailing Rock Jasmine | Bright indirect light (just back from a sunny window) | Moderate; allow top 2 cm to dry between waterings | Mildly toxic to pets |
| Transparent Moor Grass | Direct sun (at least 4-6 hours) | Every 7-14 days; keep moderately moist | Pet-safe |
| Transparent Tall Moor Grass | Bright indirect light (just back from a sunny window) | Weekly during establishment; less once settled | Pet-safe |
| Transylvanian Hepatica | Medium indirect light (a couple of metres from a window) | Every 5–7 days in spring and autumn; every 10–14 days in summer | Mildly toxic to pets |
| Transylvanian Pink | Direct sun (at least 4-6 hours) | Infrequent; allow soil to dry well between waterings | Mildly toxic to pets |
| Treasure flower | Direct sun (at least 4-6 hours) | Every 10–14 days once established; weekly when young | Mildly toxic to pets |
| Tree Fuchsia | Bright indirect light (just back from a sunny window) | Every 5-7 days in summer, reducing to every 14 days in winter | Pet-safe |
| Tree heath | Direct sun (at least 4-6 hours) | Fortnightly during the first growing season; drought-tolerant once established | Pet-safe |
| Tree Houseleek | Direct sun (at least 4-6 hours) | Every 1-2 weeks in active growth (autumn-spring); roughly every 3 weeks or less during summer dormancy | Mildly toxic to pets |
| Tree Peony | Direct sun (at least 4-6 hours) | Deeply every 7-10 days in the first two years and during dry spells; established shrubs are drought-tolerant | Toxic to pets |
| Tree rhododendron | Bright indirect light (just back from a sunny window) | Every 7–10 days in the growing season; monthly in winter | Toxic to pets |
| Trevi Fountain Pulmonaria | Low light (north window or shaded room) | Keep soil evenly moist; water every 4-6 days in dry weather, more in containers | Mildly toxic to pets |
| Trewithen Blue Ceanothus | Direct sun (at least 4-6 hours) | Every 7-10 days during establishment; established plants are drought-tolerant and need supplemental watering only in prolonged dry periods in summer | Mildly toxic to pets |
| Triangle Fern | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist during the growing season; water when the top 2-3 cm begins to dry | Toxic to pets |
| Triangular Masdevallia | Medium indirect light (a couple of metres from a window) | Daily in hot weather; every 2–3 days in spring and autumn | Pet-safe |
| Trident Maple | Direct sun (at least 4-6 hours) | Water when the top of the soil begins to dry; bonsai often need daily water in summer | Mildly toxic to pets |
| Trident Maple 'Kifu' | Direct sun (at least 4-6 hours) | When the surface begins to dry, frequently once or twice daily in summer heat | Mildly toxic to pets |
| Trim Greenhood | Medium indirect light (a couple of metres from a window) | Lightly moist during active growth (autumn–spring), roughly every 5-7 days | Pet-safe |
| Trumpet Gentian | Direct sun (at least 4-6 hours) | Regular during the growing season; reduced but not eliminated in winter | Mildly toxic to pets |
| Tsubo Bamboo Grass | Medium indirect light (a couple of metres from a window) | 2–3 times per week in summer, once a week in winter | Pet-safe |
| Tsuboii Bamboo | Bright indirect light (just back from a sunny window) | 2–3 times per week in summer, reduce in autumn and winter | Pet-safe |
| Tsusima Holly Fern | Medium indirect light (a couple of metres from a window) | When the top 1-2 cm of soil begins to dry, roughly every 5-7 days | Pet-safe |
| Tube Beardtongue | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Mildly toxic to pets |
| Tuberous Cranesbill | Direct sun (at least 4-6 hours) | Sparingly in summer; moderate in spring growing season | Mildly toxic to pets |
| Tuerckheim's Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 1–2 days in summer; every 3–5 days in cooler months | Pet-safe |
| Tufted Hair Grass | Bright indirect light (just back from a sunny window) | Keep soil consistently moist, watering deeply 1-2 times weekly in dry spells | Mildly toxic to pets |
| Tufted Loosestrife | Medium indirect light (a couple of metres from a window) | Permanently wet to shallow aquatic; bog garden or shallow pond margin | Pet-safe |
| Tufted Vetch | Direct sun (at least 4-6 hours) | Low to moderate — tolerates periodic dry spells once established | Mildly toxic to pets |
| Tulip | Direct sun (at least 4-6 hours) | Water at planting; rely on rainfall after | Toxic to pets |
| Tulipa 'Apeldoorn' | Direct sun (at least 4-6 hours) | Keep soil moist in growth; dry while dormant | Toxic to pets |
| Tulipa 'Menton' | Direct sun (at least 4-6 hours) | Water in at planting, then only during dry spells in spring | Toxic to pets |
| Tulipa 'Queen of Night' | Direct sun (at least 4-6 hours) | Keep soil moist in growth; dry while dormant | Toxic to pets |
| Tulipa 'Tulipa clusiana' | Direct sun (at least 4-6 hours) | Rainfall in spring; keep dry during summer dormancy | Toxic to pets |
| Tulipa sylvestris | Direct sun (at least 4-6 hours) | Rainfall in most settings; tolerates moister ground than hybrids | Toxic to pets |
| Tulista Marginata | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, about every 2-3 weeks in growth; monthly in winter | Pet-safe |
| Tulista Pumila | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 2-3 weeks in growth; monthly in winter | Pet-safe |
| Tunbridge Filmy Fern | Low light (north window or shaded room) | Continuously moist — never allow fronds to dry; mist 2–3 times daily or maintain in an enclosed humid environment | Mildly toxic to pets |
| Tunic Flower | Direct sun (at least 4-6 hours) | Low; water sparingly and only when the top 2–3 cm of soil is fully dry | Mildly toxic to pets |
| Tuolumne Fawn Lily | Medium indirect light (a couple of metres from a window) | Consistently moist during growth (late winter to early summer); do not allow to dry out even during dormancy | Mildly toxic to pets |
| Turbinicarpus pseudomacrochele | Direct sun (at least 4-6 hours) | Sparingly when fully dry in summer, roughly every 2 weeks; none in winter | Pet-safe |
| Turbinicarpus schmiedickeanus | Direct sun (at least 4-6 hours) | Sparingly when fully dry in summer, roughly every 2-3 weeks; none in winter | Pet-safe |
| Turbinicarpus valdezianus | Direct sun (at least 4-6 hours) | Very sparingly when fully dry in the growing season, roughly every 2-3 weeks; none in winter | Pet-safe |
| Turk's Head Barrel | Direct sun (at least 4-6 hours) | When soil is completely dry, approximately every 10-14 days in the growing season; every 4-6 weeks in winter | Pet-safe |
| Turkestan Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in spring and summer; sparingly in autumn; almost none in winter | Pet-safe |
| Turkestan Tulip | Direct sun (at least 4-6 hours) | Minimal; water once at planting; rely on natural rainfall during growth; completely dry during summer dormancy | Toxic to pets |
| Turkey Oak | Direct sun (at least 4-6 hours) | Occasional once established; more frequent in first 2–3 years | Mildly toxic to pets |
| Turkish Catmint | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; very sparingly in winter | Pet-safe |
| Turkish Fir | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry for young trees, roughly every 10-14 days in the first 2-3 years | Mildly toxic to pets |
| Turkish Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; very sparingly in winter | Pet-safe |
| Turkish White Sage | Direct sun (at least 4-6 hours) | Every 10-14 days; minimal once dormant in summer heat | Pet-safe |
| Turquoise Puya | Direct sun (at least 4-6 hours) | weekly in summer, monthly in winter | Pet-safe |
| Tussock Needlegrass | Direct sun (at least 4-6 hours) | Every 2-3 weeks during the first growing season; essentially rain-fed once established | Mildly toxic to pets |
| Tweedy's Lewisia | Bright indirect light (just back from a sunny window) | Regular in spring; near-dry from midsummer to early autumn | Pet-safe |
| Twiggy Lepanthes | Medium indirect light (a couple of metres from a window) | Daily misting; substrate must stay consistently moist | Pet-safe |
| Twin-Flowered Air Plant | Bright indirect light (just back from a sunny window) | Mist 2–3 times per week, or a 20-minute soak once a week | Pet-safe |
| Twin-flowered Ruschia | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in the growing season; very sparingly (once every 3-4 weeks) in winter | Pet-safe |
| Twinleaf | Medium indirect light (a couple of metres from a window) | 2 times per week during spring growth; reduce through summer | Mildly toxic to pets |
| Twinspur | Direct sun (at least 4-6 hours) | 2–3 times per week during active growth; reduce during cooler periods | Pet-safe |
| Twisted Aichryson | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in spring and summer; monthly in winter | Mildly toxic to pets |
| Twisted Barrel Cactus | Direct sun (at least 4-6 hours) | When fully dry, about every 2-3 weeks in summer; keep dry in winter | Mildly toxic to pets |
| Twisted Restrepia | Medium indirect light (a couple of metres from a window) | Every 2–4 days; maintain light but consistent moisture | Pet-safe |
| Twisted Stanhopea | Medium indirect light (a couple of metres from a window) | 3–5 times per week in active growth; reduce in winter | Pet-safe |
| Twisted Trillium | Medium indirect light (a couple of metres from a window) | Moderate moisture in spring; reduced in summer dormancy | Mildly toxic to pets |
| Twisted-Fruit Air Plant | Bright indirect light (just back from a sunny window) | Mist daily in spring through autumn; reduce in winter | Pet-safe |
| Two-Colour Vygie | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; monthly or less in winter | Mildly toxic to pets |
| Two-edged Pleurothallis | Medium indirect light (a couple of metres from a window) | Every 1–2 days in warm months; every 2–3 days in winter | Pet-safe |
| Two-Flowered Everlasting Pea | Direct sun (at least 4-6 hours) | Every 7–10 days during dry spells; rarely needs watering once established | Mildly toxic to pets |
| Two-leaf Squill | Bright indirect light (just back from a sunny window) | Naturally watered in spring; needs no supplemental irrigation once established | Toxic to pets |
| Two-Lobed Cone Plant | Direct sun (at least 4-6 hours) | Strictly seasonal: water sparingly from September to March (active growth and flowering); completely dry from April/May through August | Mildly toxic to pets |
| Two-Ranked Aechmea | Bright indirect light (just back from a sunny window) | Refresh central cup every 7–10 days; water soil every 2–3 weeks | Pet-safe |
| Two-Ranked Air Plant | Bright indirect light (just back from a sunny window) | Twice weekly in summer, once weekly in winter | Pet-safe |
| Two-Row Stonecrop | Direct sun (at least 4-6 hours) | Every 10-14 days until established; essentially rain-fed once rooted | Pet-safe |
| Two-Spiked Billbergia | Bright indirect light (just back from a sunny window) | Every 2–3 weeks (soil); cup refreshed every 2–4 weeks | Pet-safe |
| Two-toned Pineapple Lily | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days during the growing season | Toxic to pets |
| Typha angustifolia | Direct sun (at least 4-6 hours) | Keep permanently wet; grow in standing water up to about 30-50 cm deep or saturated soil | Mildly toxic to pets |
| Typha latifolia | Direct sun (at least 4-6 hours) | Keep permanently wet; grow in standing water 0-30 cm deep or in saturated soil | Mildly toxic to pets |
| Typha minima | Direct sun (at least 4-6 hours) | Keep permanently wet; grow in shallow water up to about 5-15 cm over the crown or in saturated soil | Mildly toxic to pets |
| Ugni | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 5-7 days | Mildly toxic to pets |
| Ukhrul Fan Palm | Bright indirect light (just back from a sunny window) | Weekly during the growing season, reduced in winter | Pet-safe |
| Umbel Sun Rose | Direct sun (at least 4-6 hours) | Very low — minimal irrigation needed; drought-tolerant once established | Mildly toxic to pets |
| Umbrella Magnolia | Medium indirect light (a couple of metres from a window) | Weekly during dry spells; keep soil evenly moist but not waterlogged | Pet-safe |
| Unarmed Hedgehog Cactus | Direct sun (at least 4-6 hours) | When soil is completely dry, every 10-14 days in summer; once a month or less in winter | Pet-safe |
| Unbranched Bur-reed | Direct sun (at least 4-6 hours) | Permanently aquatic or waterlogged; tolerates 0–60 cm (0–24 in) water depth | Pet-safe |
| Unequal-Leaf Gibbaeum | Bright indirect light (just back from a sunny window) | Sparingly in winter (active season); essentially zero in summer (June–September dormancy) | Pet-safe |
| Upright Hedge Parsley | Medium indirect light (a couple of metres from a window) | Moderate; keep soil evenly moist | Mildly toxic to pets |
| Upright Plum Yew | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Ursula's Red Painted Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days in the growing season, reduce in winter | Pet-safe |
| Uvaia | Direct sun (at least 4-6 hours) | Weekly; keep consistently moist during establishment, more drought-tolerant once mature | Pet-safe |
| Valdez's Aztec Cactus | Bright indirect light (just back from a sunny window) | When the mix is nearly dry, roughly every 14-28 days in the growing season; once every 4-6 weeks in winter | Pet-safe |
| Valentine Bleeding Heart | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water every 4-6 days in spring, easing off as it goes dormant | Toxic to pets |
| Valentine's Crown Vetch | Direct sun (at least 4-6 hours) | Low to moderate — once every 2–3 weeks when established | Toxic to pets |
| Vallisneria-Leaved Butterwort | Bright indirect light (just back from a sunny window) | Keep constantly moist to wet during the growing season (spring–autumn); reduce to near-dry during winter hibernaculum phase | Mildly toxic to pets |
| Vandell's Rock Jasmine | Direct sun (at least 4-6 hours) | Very low — water from below, keep dry in winter | Mildly toxic to pets |
| Vanilla Trumpet Vine | Direct sun (at least 4-6 hours) | Twice weekly during summer; weekly or less in winter | Mildly toxic to pets |
| Variable Zamia | Bright indirect light (just back from a sunny window) | Every 10–14 days in growing season; every 3–5 weeks in winter | Toxic to pets |
| Varied-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established; more frequently in the first season | Mildly toxic to pets |
| Variegata Brunnera | Low light (north window or shaded room) | Keep soil reliably moist; water when the top 2-3 cm dries, roughly every 4-6 days in warm spells | Mildly toxic to pets |
| Variegata Purple Moor Grass | Bright indirect light (just back from a sunny window) | Every 7-14 days; keep moderately moist to moist | Pet-safe |
| Variegated Basket Grass | Bright indirect light (just back from a sunny window) | Every 5–7 days in growing season; every 10–14 days in winter | Pet-safe |
| Variegated Bear's Paw | Bright indirect light (just back from a sunny window) | Every 3–4 weeks, or when soil is completely dry | Toxic to pets |
| Variegated Carrion Flower | Bright indirect light (just back from a sunny window) | Every 14–21 days in summer; very sparingly (once monthly or less) in winter | Pet-safe |
| Variegated Cast Iron Plant | Low light (north window or shaded room) | When the top 3-5 cm of soil is dry, roughly every 10-14 days | Pet-safe |
| Variegated Cord Grass | Direct sun (at least 4-6 hours) | Keep consistently moist to wet; never let it dry out | Mildly toxic to pets |
| Variegated Elephant Bush | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 1-2 weeks in summer, monthly in winter | Pet-safe |
| Variegated Elephant Bush | Bright indirect light (just back from a sunny window) | When the top 3–4 cm of soil is dry, roughly every 10–14 days in summer and every 3–4 weeks in winter | Pet-safe |
| Variegated Giant Reed | Direct sun (at least 4-6 hours) | Frequently; keep consistently moist | Mildly toxic to pets |
| Variegated Hiba Arborvitae | Bright indirect light (just back from a sunny window) | Once every 7-10 days, keeping soil consistently moist but not waterlogged | Toxic to pets |
| Variegated Incense Cedar | Direct sun (at least 4-6 hours) | Once every 10-14 days once established; more frequently in its first two seasons | Mildly toxic to pets |
| Variegated Liveforever | Bright indirect light (just back from a sunny window) | Every 10–14 days from late autumn through spring when leaves are present; withhold completely in summer dormancy | Pet-safe |
| Variegated pieris | Bright indirect light (just back from a sunny window) | Weekly; do not allow soil to dry out | Toxic to pets |
| Variegated Purple Moor Grass | Bright indirect light (just back from a sunny window) | Weekly during growing season; keep consistently moist | Pet-safe |
| Variegated Velvet Grass | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Variegated Yellow Sedge | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water every 5-7 days in dry spells and never let containers dry out | Mildly toxic to pets |
| Varnished Air Plant | Bright indirect light (just back from a sunny window) | Weekly soak | Pet-safe |
| Vasey's Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist through spring; reduce over summer dormancy | Mildly toxic to pets |
| Veilchenblau Rose | Bright indirect light (just back from a sunny window) | Deeply once or twice weekly while establishing; mature plants when the top few centimetres of soil dry, and they tolerate some drought | Pet-safe |
| Veitch Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Pet-safe |
| Velick's Air Plant | Bright indirect light (just back from a sunny window) | Weekly soak | Pet-safe |
| Velvet Ash | Direct sun (at least 4-6 hours) | Low once established; deep watering every 2–4 weeks in summer heat | Pet-safe |
| Velvet Cotyledon | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season, every 3–4 weeks in winter | Toxic to pets |
| Velvet Sage | Bright indirect light (just back from a sunny window) | Weekly | Pet-safe |
| Venus Flytrap 'Dente' | Direct sun (at least 4-6 hours) | Keep the soil constantly wet; top up the tray as it dries, near-daily in summer | Pet-safe |
| Verity's Liveforever | Direct sun (at least 4-6 hours) | Every 10–14 days in the cool growing season (October–April); completely dry June–September | Pet-safe |
| Veronica beccabunga | Direct sun (at least 4-6 hours) | Keep permanently wet; never let the rootzone dry out | Mildly toxic to pets |
| Veronica longifolia 'Blauriesin' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil are drying, about weekly in summer | Mildly toxic to pets |
| Veronica spicata 'Royal Candles' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly weekly in the first season | Mildly toxic to pets |
| Veronica spicata subsp. incana | Direct sun (at least 4-6 hours) | Every 10-14 days once established, when soil is dry | Mildly toxic to pets |
| Veronicastrum virginicum | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water deeply in dry spells | Mildly toxic to pets |
| Veronicastrum virginicum 'Fascination' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Victoria Lady Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season; reduce in winter | Pet-safe |
| Vidal's Lady Fern | Medium indirect light (a couple of metres from a window) | 2–3 times per week in growing season; reduce in winter | Pet-safe |
| Villete's Living Stone | Direct sun (at least 4-6 hours) | Only when the plant's old leaf pair is fully shrivelled, roughly every 3–4 weeks during the autumn–winter growing period; none in summer dormancy | Pet-safe |
| Villete's Living Stones | Direct sun (at least 4-6 hours) | Every 3–5 weeks in autumn; none in summer or winter | Pet-safe |
| Vilmorin Japanese Cedar | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Vilmorin's rowan | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Viola 'Sorbet Raspberry' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 3-5 days; containers more often | Pet-safe |
| Viola × wittrockiana 'Delta Pure Yellow' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, typically every 3-5 days; containers dry faster | Pet-safe |
| Viola cornuta 'Etain' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, generally every 3-5 days; more in containers and heat | Pet-safe |
| Violet Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Pet-safe |
| Violet-Flowered Sage | Direct sun (at least 4-6 hours) | Every 7 days in summer; every 14–21 days in winter | Mildly toxic to pets |
| Virgin Orchid | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; reduce to every 10–14 days in autumn–winter rest | Pet-safe |
| Virgin's Bower | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 10-14 days once established | Toxic to pets |
| Virginia Bluebells | Medium indirect light (a couple of metres from a window) | 1–2 inches per week in spring; minimal needed once dormant | Pet-safe |
| Virginia Chain Fern | Medium indirect light (a couple of metres from a window) | Frequently — keep soil consistently moist to wet | Pet-safe |
| Virginia Pine Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm is dry, frequently daily in summer and every few days in cooler months | Pet-safe |
| Virginia Spring Beauty | Bright indirect light (just back from a sunny window) | Moderate in spring; negligible once dormant in summer | Pet-safe |
| Virginia Stock | Bright indirect light (just back from a sunny window) | Weekly (keep soil evenly moist but not waterlogged) | Mildly toxic to pets |
| Vitis coignetiae | Direct sun (at least 4-6 hours) | Water young vines in dry spells; established plants are largely self-sufficient | Toxic to pets |
| Vivellii winter heath | Direct sun (at least 4-6 hours) | Weekly for new plantings; every 2–3 weeks for established plants during dry periods | Pet-safe |
| Wagner's Air Plant | Bright indirect light (just back from a sunny window) | 2–3 times per week (misting) or weekly soak | Pet-safe |
| Wagner's Sage | Bright indirect light (just back from a sunny window) | Water regularly to maintain consistent moisture | Pet-safe |
| Wagners Windmill Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days depending on season | Pet-safe |
| Waldbrunn Spruce | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing; deep watering when the top 5 cm of soil dries | Pet-safe |
| Walking Fern | Low light (north window or shaded room) | Keep substrate evenly moist at all times; check every 3-5 days and never let it dry fully | Pet-safe |
| Wall Monanthes | Medium indirect light (a couple of metres from a window) | Every 1–2 weeks in the growing season; every 3–4 weeks in winter | Pet-safe |
| Wall Rue | Bright indirect light (just back from a sunny window) | Rarely needs watering in the ground; water container plants only when the crevice substrate dries | Pet-safe |
| Wall-rue Spleenwort | Medium indirect light (a couple of metres from a window) | Sparingly — only when the substrate is dry to the touch | Mildly toxic to pets |
| Wallich's Cranesbill | Bright indirect light (just back from a sunny window) | Once or twice weekly during dry spells once established | Pet-safe |
| Wallich's Strobilanthes | Bright indirect light (just back from a sunny window) | Weekly during the growing season; reduce after foliage dies back in autumn | Mildly toxic to pets |
| Wallichiana Fern | Medium indirect light (a couple of metres from a window) | When the top 2 cm of soil begins to dry, about every 5-7 days | Mildly toxic to pets |
| Wallis's Dragon Orchid | Medium indirect light (a couple of metres from a window) | Every 2–3 days; medium kept continuously moist | Pet-safe |
| Waras' Parodia | Bright indirect light (just back from a sunny window) | Every 10-14 days in spring/summer; every 3-4 weeks in autumn; once in winter or withheld entirely | Mildly toxic to pets |
| Warty Gasteria | Bright indirect light (just back from a sunny window) | When the soil is fully dry, roughly every 2-3 weeks in summer, monthly or less in winter | Pet-safe |
| Warty Living Stone | Direct sun (at least 4-6 hours) | Every 14-21 days during active autumn-to-spring growth; completely none in summer | Pet-safe |
| Warty Living Stones | Direct sun (at least 4-6 hours) | Every 3–5 weeks in autumn; none in summer or deep winter | Pet-safe |
| Warty Scaphosepalum | Medium indirect light (a couple of metres from a window) | When the surface of the medium is just barely dry, roughly every 3-5 days | Pet-safe |
| Water Avens | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist to wet; never let it dry out | Mildly toxic to pets |
| Water Forget-me-not | Bright indirect light (just back from a sunny window) | Permanently moist to marginal aquatic; up to 10 cm over crown | Mildly toxic to pets |
| Water Horsetail | Direct sun (at least 4-6 hours) | Submerged or saturated | Mildly toxic to pets |
| Water Lily Cactus | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in spring and summer; every 3-4 weeks in autumn; almost none in winter | Pet-safe |
| Water Speedwell | Direct sun (at least 4-6 hours) | Permanently wet to shallow submersion | Pet-safe |
| Water Tupelo | Direct sun (at least 4-6 hours) | Constant to seasonally flooded; extremely wet tolerant | Mildly toxic to pets |
| Water Violet | Bright indirect light (just back from a sunny window) | Fully submerged aquatic; grows in 20–80 cm of water | Pet-safe |
| Waterberg Cycad | Direct sun (at least 4-6 hours) | Every 3–5 weeks | Toxic to pets |
| Watercress Fern | Medium indirect light (a couple of metres from a window) | When the surface starts to dry, roughly every 3-5 days | Mildly toxic to pets |
| Waterfall Gladiolus | Direct sun (at least 4-6 hours) | Every 5-7 days during active growth; reduce significantly as foliage dies back | Mildly toxic to pets |
| Waterlily Tulip | Direct sun (at least 4-6 hours) | Rainfall-dependent during growing season; needs dry summer dormancy | Toxic to pets |
| wavy hair grass | Bright indirect light (just back from a sunny window) | Water every 1-2 weeks; drought-tolerant once established in cool climates | Mildly toxic to pets |
| Wavy Nerine | Direct sun (at least 4-6 hours) | Very little to none in summer dormancy; regular from when flower spikes emerge in autumn through spring; stop as foliage dies back | Toxic to pets |
| Weasel Stomatium | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; monthly or less in winter | Mildly toxic to pets |
| Weaver's Bamboo | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week; daily in hot weather | Pet-safe |
| Webb's Germander | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry between waterings | Mildly toxic to pets |
| Weberbauer's Lepanthes | Medium indirect light (a couple of metres from a window) | Near-daily misting; substrate must not dry completely at any point | Pet-safe |
| Weeping Blue Atlas Cedar | Direct sun (at least 4-6 hours) | Every 1-2 weeks while young, then only in drought | Mildly toxic to pets |
| Weeping Blue Atlas Cedar | Direct sun (at least 4-6 hours) | Weekly during establishment (2–3 years); then rainfall-dependent | Mildly toxic to pets |
| Weeping Eastern Hemlock | Medium indirect light (a couple of metres from a window) | Every 1–2 weeks; more in hot or dry conditions | Pet-safe |
| Weeping Eastern Hemlock | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Mildly toxic to pets |
| Weeping European Larch | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days during the growing season | Mildly toxic to pets |
| weeping forsythia | Direct sun (at least 4-6 hours) | Weekly during first growing season; established plants need watering only during prolonged drought | Mildly toxic to pets |
| Weeping Giant Sequoia | Direct sun (at least 4-6 hours) | Every 1–2 weeks when young; monthly once established in moist climates | Pet-safe |
| Weeping Japanese Larch | Direct sun (at least 4-6 hours) | Once every 7-10 days during the growing season; reduce in winter when dormant | Mildly toxic to pets |
| Weeping Nootka Cypress | Direct sun (at least 4-6 hours) | Regularly during establishment; moderate once mature | Pet-safe |
| Weeping Nootka Cypress | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days for young plants | Mildly toxic to pets |
| Weeping Norway Spruce | Direct sun (at least 4-6 hours) | Keep soil evenly moist; water weekly in dry spells, more for young trees | Mildly toxic to pets |
| Weeping silver pear | Direct sun (at least 4-6 hours) | Weekly when establishing; monthly once established | Mildly toxic to pets |
| Weeping White Mulberry | Direct sun (at least 4-6 hours) | Weekly for first two years; monthly once established in temperate climates | Mildly toxic to pets |
| Weigela 'Bristol Ruby' | Direct sun (at least 4-6 hours) | Weekly while establishing; established shrubs need water mainly in dry spells | Mildly toxic to pets |
| Weigela 'Eva Rathke' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil feels dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Weigela 'Florida Purpurea' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Weigela 'Midnight Wine' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Weigela 'My Monet' | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil dries, about weekly while establishing | Pet-safe |
| Weigela 'My Monet' | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in the growing season | Mildly toxic to pets |
| Weigela 'Nana Variegata' | Bright indirect light (just back from a sunny window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days once established | Pet-safe |
| Weigela 'Red Prince' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during active growth | Mildly toxic to pets |
| Weigela 'Sunny Princess' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Weigela 'Wine & Roses' | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil is dry, about weekly while establishing | Pet-safe |
| Weigela 'Wine & Roses' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-10 days during the growing season | Mildly toxic to pets |
| Welsh Poppy | Medium indirect light (a couple of metres from a window) | Moderate; moist but not waterlogged | Toxic to pets |
| Wendland's Lepanthes | Medium indirect light (a couple of metres from a window) | Daily or every 2 days; never dry out | Pet-safe |
| Wenzel's Chain Orchid | Bright indirect light (just back from a sunny window) | When the top 1-2 cm of the potting medium feels dry, roughly every 5-7 days | Pet-safe |
| Werner's Living Stone | Direct sun (at least 4-6 hours) | Once every 3–5 weeks during the autumn–winter growing period only; completely dry through spring and summer | Pet-safe |
| West African Pitcairnia | Bright indirect light (just back from a sunny window) | Water consistently to keep the growing medium evenly moist during the growing season; allow the top 2–3 cm to dry between waterings in winter. | Mildly toxic to pets |
| Western Arborvitae Zebrina | Direct sun (at least 4-6 hours) | Deeply every 5-7 days the first two years, then during dry spells | Mildly toxic to pets |
| Western Bog Laurel | Direct sun (at least 4-6 hours) | Frequent to constant; keep wet | Toxic to pets |
| Western Columbine | Bright indirect light (just back from a sunny window) | Every 5–7 days during active growth; reduce after flowering | Toxic to pets |
| Western Hemlock | Medium indirect light (a couple of metres from a window) | Weekly during establishment; regular moisture long-term | Pet-safe |
| Western Larch | Direct sun (at least 4-6 hours) | Weekly during establishment; thereafter relies on natural precipitation | Pet-safe |
| Western Skunk Cabbage | Medium indirect light (a couple of metres from a window) | Permanently moist to wet; boggy or waterlogged conditions required | Toxic to pets |
| Western Spirea | Direct sun (at least 4-6 hours) | Every 5-7 days or as needed to keep soil consistently moist | Pet-safe |
| Western Sundew | Direct sun (at least 4-6 hours) | Shallow tray method in winter–spring; dry in summer | Mildly toxic to pets |
| Western Sword Fern | Low light (north window or shaded room) | When the top 3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Western White Trillium | Medium indirect light (a couple of metres from a window) | Consistently moist spring through early summer; reduced but not completely dry in summer dormancy. | Mildly toxic to pets |
| Wheel Cactus | Direct sun (at least 4-6 hours) | Every 2-4 weeks during spring/summer growing season; once every 6 weeks in autumn; sparingly or not at all in winter | Mildly toxic to pets |
| Wheki Tree Fern | Medium indirect light (a couple of metres from a window) | Consistently moist — water deeply 2-3 times per week in dry periods during the growing season | Pet-safe |
| Wherry's Foamflower | Medium indirect light (a couple of metres from a window) | Keep soil evenly moist; water about weekly, more in dry spells | Mildly toxic to pets |
| Wherry's Foamflower | Medium indirect light (a couple of metres from a window) | Once or twice per week in the growing season; reduce significantly in winter. | Mildly toxic to pets |
| Whirling Butterflies Gaura | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 7-14 days during the growing season | Pet-safe |
| Whirlwind Blue Fan Flower | Direct sun (at least 4-6 hours) | When the top 2-3 cm of potting mix is dry, roughly every 4-6 days in summer | Pet-safe |
| White Air Plant | Bright indirect light (just back from a sunny window) | Soak for 20–30 minutes once or twice a week | Pet-safe |
| White Anacampseros | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in summer and monthly or less in winter | Mildly toxic to pets |
| White Arrow Arum | Bright indirect light (just back from a sunny window) | Continuously moist to waterlogged; never allow to dry out | Toxic to pets |
| White Bird of Paradise | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, roughly every 7-14 days depending on season and temperature | Mildly toxic to pets |
| White Campion | Bright indirect light (just back from a sunny window) | Low to moderate; allow soil to approach dryness between waterings | Mildly toxic to pets |
| White Comfrey | Medium indirect light (a couple of metres from a window) | Every 5–10 days during dry periods | Mildly toxic to pets |
| White Dendrobium | Bright indirect light (just back from a sunny window) | Every 5–7 days in growth; every 2–3 weeks in winter rest | Pet-safe |
| White Dragon Mondo Grass | Medium indirect light (a couple of metres from a window) | Water when the top 2–3 cm of soil is dry, roughly every 7–10 days in the growing season | Mildly toxic to pets |
| White Egret Orchid | Bright indirect light (just back from a sunny window) | Keep consistently moist during active growth (spring–summer), roughly every 2-4 days | Pet-safe |
| White Enkianthus | Bright indirect light (just back from a sunny window) | Regularly; soil should stay evenly moist | Mildly toxic to pets |
| White Fir | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; largely drought-tolerant once mature | Pet-safe |
| White Floss Silk Tree | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 3–4 weeks in winter | Mildly toxic to pets |
| White Freesia | Direct sun (at least 4-6 hours) | Moderate during active growth (autumn to spring); completely dry during summer dormancy | Pet-safe |
| White Ginger Lily | Bright indirect light (just back from a sunny window) | Water generously every 2–4 days in active growth; reduce to sparingly in winter dormancy | Mildly toxic to pets |
| White Grand Lotus | Direct sun (at least 4-6 hours) | Aquatic — permanently in still or slow-moving water | Mildly toxic to pets |
| White Juttadinteria | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season (spring through autumn); very sparingly in winter | Mildly toxic to pets |
| White laceflower | Direct sun (at least 4-6 hours) | Every 5–7 days; allow the top 2 cm of soil to dry between waterings | Pet-safe |
| White Laelia | Bright indirect light (just back from a sunny window) | Every 5–7 days in spring and autumn; once every 2–3 weeks in summer dry rest | Pet-safe |
| White Magic Grape Hyacinth | Direct sun (at least 4-6 hours) | Moderate in spring; dry from early summer through autumn | Mildly toxic to pets |
| White Marsh Marigold | Bright indirect light (just back from a sunny window) | Permanently moist to boggy; crown should sit just above water level | Mildly toxic to pets |
| White Marsh Marigold | Bright indirect light (just back from a sunny window) | Permanently moist to wet; boggy soil or shallow pondside | Mildly toxic to pets |
| White Passionflower | Direct sun (at least 4-6 hours) | Once a week during dry spells; less in winter | Pet-safe |
| White Perfection Darley Dale heath | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| White Prairie Clover | Direct sun (at least 4-6 hours) | Water to establish; afterwards highly drought-tolerant, seldom needs watering | Mildly toxic to pets |
| White Rain Lily | Direct sun (at least 4-6 hours) | Moderately during growth; a dry period followed by watering triggers blooming | Toxic to pets |
| White Sapote | Direct sun (at least 4-6 hours) | Weekly for young trees; every 2–3 weeks for established trees; withhold during wet periods | Toxic to pets |
| White Spider Orchid | Bright indirect light (just back from a sunny window) | Moderate during autumn to spring; completely dry in summer | Pet-safe |
| White St Dabeoc's Heath | Bright indirect light (just back from a sunny window) | Moderate — water when top 2–3 cm of soil is dry | Mildly toxic to pets |
| White Stonecrop | Direct sun (at least 4-6 hours) | When soil is dry, roughly every 10-14 days in summer; little to none in winter | Pet-safe |
| White Tiger Jaws | Direct sun (at least 4-6 hours) | Every 14–21 days during the growing season (spring–autumn); once monthly or less in winter | Mildly toxic to pets |
| White Towers Toad Lily | Medium indirect light (a couple of metres from a window) | Keep evenly moist; water when the surface starts to dry, often once or twice weekly in summer | Mildly toxic to pets |
| White Trillium | Medium indirect light (a couple of metres from a window) | Weekly during spring growth; reduce after dormancy | Mildly toxic to pets |
| White Trout Lily | Medium indirect light (a couple of metres from a window) | Keep consistently moist while in growth (spring); reduce after dormancy | Mildly toxic to pets |
| White Water Lily | Direct sun (at least 4-6 hours) | Permanent aquatic — always submerged in 45-90 cm of water | Mildly toxic to pets |
| White Water Lily | Direct sun (at least 4-6 hours) | Aquatic — grows permanently submerged or in standing water | Toxic to pets |
| White Wild Indigo | Direct sun (at least 4-6 hours) | Water the first season; established plants need little to no watering | Mildly toxic to pets |
| White Wild Quinine | Direct sun (at least 4-6 hours) | Water to establish, then sparingly; drought-tolerant once rooted | Mildly toxic to pets |
| White wood aster | Medium indirect light (a couple of metres from a window) | Every 1–2 weeks during establishment; largely self-sufficient once established in woodland settings | Pet-safe |
| White Wood Aster | Medium indirect light (a couple of metres from a window) | When the top 3-5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| White-Bark Magnolia | Bright indirect light (just back from a sunny window) | Weekly during dry spells for the first 3 years; every 2 weeks when established | Pet-safe |
| White-blue Sage | Direct sun (at least 4-6 hours) | Low to moderate — seasonal wet–dry cycle; allow soil to dry between waterings | Mildly toxic to pets |
| White-Budded Sundew | Bright indirect light (just back from a sunny window) | Keep the tray permanently moist in the growing season; reduce in summer heat dormancy | Mildly toxic to pets |
| White-Flowered Crown Cactus | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; once a month or less from October to February | Pet-safe |
| White-Flowered Lycaste | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 14–21 days during winter rest | Pet-safe |
| White-haired Crown Cactus | Direct sun (at least 4-6 hours) | Weekly in summer; every 10–14 days in spring and autumn; once a month or none in winter | Pet-safe |
| White-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Occasional — every 2–3 weeks when established; weekly in the first season | Mildly toxic to pets |
| White-Lip Oncidium | Bright indirect light (just back from a sunny window) | Every 5–7 days in active growth; every 14–21 days in winter rest | Pet-safe |
| White-pink Stomatium | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; every 4-6 weeks or less in winter | Mildly toxic to pets |
| White-Powder Bamboo | Direct sun (at least 4-6 hours) | Weekly in the growing season; fortnightly when dormant | Pet-safe |
| White-Spined Thelocactus | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 14-21 days in the growing season; suspend almost entirely in winter. | Pet-safe |
| White-topped Pitcher Plant | Direct sun (at least 4-6 hours) | Keep constantly moist to wet — sit pots in 2–5 cm of standing water during the growing season | Mildly toxic to pets |
| Whitelock's Ceratozamia | Medium indirect light (a couple of metres from a window) | Weekly to every 10 days in growing season; reduce in winter | Toxic to pets |
| Whitley's Speedwell | Direct sun (at least 4-6 hours) | Every 10–14 days during active growth; minimal in winter | Pet-safe |
| Whorled Milkweed | Direct sun (at least 4-6 hours) | Water to establish, then rarely; highly drought-tolerant once settled | Toxic to pets |
| Whorled Rosinweed | Bright indirect light (just back from a sunny window) | Every 1-2 weeks once established | Pet-safe |
| Whorled Solomon's Seal | Medium indirect light (a couple of metres from a window) | Every 5–7 days during the growing season; reduce in autumn | Mildly toxic to pets |
| Whorled Water Milfoil | Direct sun (at least 4-6 hours) | Permanently submerged | Pet-safe |
| Wickwar Flame heather | Direct sun (at least 4-6 hours) | Weekly during establishment, then as needed | Pet-safe |
| Wide Eye Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn to late winter; none in summer | Pet-safe |
| Wide-leaved Grape Hyacinth | Bright indirect light (just back from a sunny window) | Every 7–10 days in spring; dry over summer | Mildly toxic to pets |
| Wild Blue Phlox | Medium indirect light (a couple of metres from a window) | Weekly; keep soil evenly moist | Mildly toxic to pets |
| Wild Cherry Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil begins to dry, often daily in summer | Toxic to pets |
| Wild Crabapple Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm is dry, often daily in summer and much less in winter dormancy | Toxic to pets |
| Wild Gazania | Direct sun (at least 4-6 hours) | Every 10–14 days (very drought-tolerant once established) | Mildly toxic to pets |
| Wild jasmine | Bright indirect light (just back from a sunny window) | Once or twice a week during active growth; reduce in winter | Pet-safe |
| Wild Lupine | Direct sun (at least 4-6 hours) | Water to establish, then rarely; it is drought-tolerant once settled | Toxic to pets |
| Wild nemesia | Direct sun (at least 4-6 hours) | Every 7–14 days once established; more frequently when young | Pet-safe |
| Wild pansy | Bright indirect light (just back from a sunny window) | Every 5–7 days; keep soil evenly moist but not wet | Pet-safe |
| Wild Quinine | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Wild Rose | Direct sun (at least 4-6 hours) | Weekly while establishing, then rarely once mature | Pet-safe |
| Wild's Pincushion | Direct sun (at least 4-6 hours) | Every 10-14 days in summer; once every 3-4 weeks in winter | Pet-safe |
| Wildfire Black Tupelo | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Wildwood Twist Painted Fern | Medium indirect light (a couple of metres from a window) | Every 5–7 days; maintain consistent soil moisture | Pet-safe |
| William Buchanan heath | Bright indirect light (just back from a sunny window) | Moderate; water regularly, especially during flowering and in dry summers | Pet-safe |
| Williams rhododendron | Bright indirect light (just back from a sunny window) | Every 7–10 days in growing season; reduce to monthly in winter | Toxic to pets |
| Willow Gentian | Medium indirect light (a couple of metres from a window) | Regular; maintain consistently moist soil throughout the growing season | Mildly toxic to pets |
| Wilman's Ebracteola | Direct sun (at least 4-6 hours) | When soil is completely dry, roughly every 10-14 days during the spring-autumn growing season; very sparingly (once every 4-6 weeks) in winter | Pet-safe |
| Wilmot's Dinteranthus | Direct sun (at least 4-6 hours) | Autumn only (2 watering cycles); stop completely in spring while new leaves emerge; minimal in early winter | Pet-safe |
| Wilmot's Dinteranthus | Direct sun (at least 4-6 hours) | Every 3–5 weeks during autumn through early spring; completely dry June–August | Pet-safe |
| Wilson Spruce | Direct sun (at least 4-6 hours) | Weekly when young; established trees are drought-tolerant | Pet-safe |
| Wilson's Filmy Fern | Low light (north window or shaded room) | Continuously moist — fronds must never dry; maintain in a sealed humid enclosure with permanent moisture at the rhizomes | Mildly toxic to pets |
| Wiltoni Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days in year one, then rarely | Mildly toxic to pets |
| Window Plant | Direct sun (at least 4-6 hours) | Every 3–4 weeks in spring and summer; minimal in winter | Pet-safe |
| Wine Cups Babiana | Direct sun (at least 4-6 hours) | Water during active growth (autumn to spring); cease completely once foliage yellows | Mildly toxic to pets |
| Winter Aconite | Medium indirect light (a couple of metres from a window) | Relies on natural rainfall; keep soil moist during active growth | Toxic to pets |
| Winter Gem Boxwood | Medium indirect light (a couple of metres from a window) | When the top 5 cm of soil is dry, about weekly while establishing | Toxic to pets |
| Winter Gold Mugo Pine | Direct sun (at least 4-6 hours) | Weekly for the first two seasons; established plants every 2-3 weeks in drought | Mildly toxic to pets |
| Winter heath | Direct sun (at least 4-6 hours) | Established plants: every 2–3 weeks in dry spells; new plants: weekly for the first season | Pet-safe |
| Winterberry Holly 'Winter Red' | Direct sun (at least 4-6 hours) | Keep consistently moist; water regularly in dry spells | Toxic to pets |
| Wintergreen Barberry | Bright indirect light (just back from a sunny window) | When the top 5-8 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Wintergreen Boxwood | Bright indirect light (just back from a sunny window) | When the top 3-5 cm of soil is dry, about weekly in summer | Toxic to pets |
| Wintersweet | Direct sun (at least 4-6 hours) | Water in dry spells; moderate once established | Mildly toxic to pets |
| Wintertime prickly heath | Bright indirect light (just back from a sunny window) | Regular; keep evenly moist | Toxic to pets |
| Wire-stem Tylecodon | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season (autumn–spring); once per month or less in summer dormancy | Toxic to pets |
| Wisley 2008 Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season; more in heat or sandy soil | Pet-safe |
| Wisley Pearl Gaultheria | Bright indirect light (just back from a sunny window) | Regularly; keep soil evenly moist | Toxic to pets |
| Wisteria 'Amethyst Falls' | Direct sun (at least 4-6 hours) | Weekly while establishing; water in summer drought | Toxic to pets |
| Wisteria floribunda | Direct sun (at least 4-6 hours) | Water deeply in dry spells, particularly through bud development; mature plants tolerate some drought | Toxic to pets |
| Wisteria floribunda 'Multijuga' | Direct sun (at least 4-6 hours) | Water deeply in dry weather, especially during flowering and bud set; established plants tolerate moderate drought | Toxic to pets |
| Wisteria sinensis | Direct sun (at least 4-6 hours) | Water deeply during dry spells, especially while flower buds form; established plants are fairly drought-tolerant | Toxic to pets |
| Wisteria sinensis 'Alba' | Direct sun (at least 4-6 hours) | Water deeply during dry spells, especially as buds form; established plants tolerate some drought | Toxic to pets |
| Witch Hazel | Bright indirect light (just back from a sunny window) | Keep evenly moist; water in dry spells | Mildly toxic to pets |
| Witteberg Cone Plant | Bright indirect light (just back from a sunny window) | Every 2–3 weeks in autumn–winter; almost none in summer | Pet-safe |
| Wittig's Sophronitis | Bright indirect light (just back from a sunny window) | When the growing medium surface approaches dryness, roughly every 6-9 days | Pet-safe |
| Wolf Eyes Kousa Dogwood | Bright indirect light (just back from a sunny window) | Weekly during establishment; every 10–14 days once mature | Mildly toxic to pets |
| Wolffia arrhiza | Bright indirect light (just back from a sunny window) | Floats permanently on still water; no separate watering | Mildly toxic to pets |
| Wollaston's Holly Fern | Low light (north window or shaded room) | Every 3–5 days; keep moist but well-drained | Pet-safe |
| Wonga Wonga Vine | Bright indirect light (just back from a sunny window) | Every 7–10 days when young; largely self-sufficient once established in ground | Mildly toxic to pets |
| Wood Anemone | Medium indirect light (a couple of metres from a window) | Weekly during spring growth; none required during summer dormancy | Toxic to pets |
| Wood Avens | Medium indirect light (a couple of metres from a window) | Low to moderate — rain-fed in shade | Pet-safe |
| Wood Club-rush | Medium indirect light (a couple of metres from a window) | Permanently moist to wet; tolerates shallow standing water | Pet-safe |
| Wood Fern 'The King' | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Mildly toxic to pets |
| Wood Forget-me-not | Medium indirect light (a couple of metres from a window) | Moderate; keep soil moist but well-drained | Pet-safe |
| Wood Melic | Medium indirect light (a couple of metres from a window) | Keep evenly moist while establishing; tolerates dry shade once rooted | Mildly toxic to pets |
| Wood Melick | Medium indirect light (a couple of metres from a window) | Infrequently; drought-tolerant under shade | Pet-safe |
| Wood Sedge | Low light (north window or shaded room) | Keep evenly moist; water weekly or more in summer | Pet-safe |
| wood small-reed | Direct sun (at least 4-6 hours) | Drought-tolerant once established; occasional deep watering in first season | Pet-safe |
| Wood Vetch | Medium indirect light (a couple of metres from a window) | Low to moderate — prefers moderate moisture with periods of drying | Mildly toxic to pets |
| Wood's Cotyledon | Bright indirect light (just back from a sunny window) | Every 10–14 days when actively growing, every 3–4 weeks in winter | Toxic to pets |
| Woodland Sage | Direct sun (at least 4-6 hours) | Low to moderate; drought tolerant once established | Pet-safe |
| Woodsia ilvensis | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days | Mildly toxic to pets |
| Woodsia obtusa | Medium indirect light (a couple of metres from a window) | When the top 2-3 cm of soil is dry, roughly every 5-8 days | Mildly toxic to pets |
| Woodwardia fimbriata | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist to wet; check every 2-4 days in growth | Mildly toxic to pets |
| Woodwardia unigemmata | Bright indirect light (just back from a sunny window) | Keep evenly moist; water when the top 2-3 cm of soil begins to dry, roughly every 4-7 days in growth | Mildly toxic to pets |
| Woolly Jerusalem Sage | Direct sun (at least 4-6 hours) | Low — once every 2–3 weeks once established; minimal in winter | Mildly toxic to pets |
| Woolly Lip Fern | Direct sun (at least 4-6 hours) | every 2-4 weeks (highly drought-tolerant) | Mildly toxic to pets |
| Woolly Lip Fern | Bright indirect light (just back from a sunny window) | When the soil is completely dry, approximately every 14-21 days in summer, monthly in winter | Pet-safe |
| Woolly Weingartia | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in the growing season; once monthly or less in winter. | Pet-safe |
| Woolly yarrow | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; minimal supplemental watering needed | Mildly toxic to pets |
| Wooly-leaf White Sapote | Direct sun (at least 4-6 hours) | Water frequently when young; every 1–2 weeks once established; reduce after harvest | Toxic to pets |
| Woven Matucana | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, every 10-14 days in summer | Pet-safe |
| Wrinkled Elatostema | Low light (north window or shaded room) | Every 3–5 days; soil should remain consistently moist | Pet-safe |
| Wulfen's Alyssum | Direct sun (at least 4-6 hours) | Every 14–21 days during growing season; very little in winter | Pet-safe |
| Wych Elm Bonsai | Direct sun (at least 4-6 hours) | When the top 2 cm of soil begins to dry, often daily in summer | Mildly toxic to pets |
| Xalapa Sage | Direct sun (at least 4-6 hours) | Allow the top 5 cm of soil to dry between waterings | Pet-safe |
| Yakushima Rhododendron | Bright indirect light (just back from a sunny window) | Weekly during dry weather; do not allow to dry out in summer or before frost | Toxic to pets |
| Yakushima Rhododendron 'Yaku Princess' | Bright indirect light (just back from a sunny window) | About weekly, more during heat; water when the top 2-3 cm of soil is dry | Toxic to pets |
| Yarrow 'Moonshine' | Direct sun (at least 4-6 hours) | When the top few centimeters of soil are dry, roughly every 7-14 days | Mildly toxic to pets |
| Yellow Azalea | Bright indirect light (just back from a sunny window) | Weekly during dry spells; established plants are reasonably drought-tolerant but flower best with consistent moisture | Toxic to pets |
| Yellow Baby Toes | Direct sun (at least 4-6 hours) | Every 2–3 weeks during active growth (autumn through spring); essentially none through summer dormancy | Pet-safe |
| Yellow Birch | Direct sun (at least 4-6 hours) | Consistently moist; water deeply 1-2 times per week during establishment and in dry spells | Pet-safe |
| Yellow Clintonia | Low light (north window or shaded room) | Twice weekly in dry spells; maintain even soil moisture throughout the growing season | Pet-safe |
| Yellow Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn; withhold entirely in summer | Pet-safe |
| Yellow Cone Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks from late summer through early spring; fully dry throughout June–August | Pet-safe |
| Yellow Crocus | Direct sun (at least 4-6 hours) | Very low — water once at planting; rainfall sufficient during growth; completely dry in summer | Mildly toxic to pets |
| Yellow Fairybells | Medium indirect light (a couple of metres from a window) | Regular; maintain consistent moisture | Mildly toxic to pets |
| Yellow False Jasmine | Bright indirect light (just back from a sunny window) | Water every 7-10 days during the growing season; reduce to every 2-3 weeks once established and dormancy slows growth | Toxic to pets |
| Yellow Fawnlily | Medium indirect light (a couple of metres from a window) | Consistently moist during active growth (late winter to late spring); minimal after dormancy | Mildly toxic to pets |
| Yellow Firethorn | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days | Mildly toxic to pets |
| Yellow Foxglove | Bright indirect light (just back from a sunny window) | When the top 2-3 cm of soil is dry, roughly weekly in dry spells | Toxic to pets |
| Yellow Gentian | Direct sun (at least 4-6 hours) | Regular; keep evenly moist during the growing season — never allow to fully dry out | Mildly toxic to pets |
| Yellow Giant Hyssop | Bright indirect light (just back from a sunny window) | Every 7–10 days during the growing season; minimal in winter | Pet-safe |
| Yellow Ginger Lily | Bright indirect light (just back from a sunny window) | Generously during the growing season; greatly reduced in winter dormancy | Mildly toxic to pets |
| Yellow Glacier Lily | Medium indirect light (a couple of metres from a window) | Regular during spring growth; reduce sharply after dormancy | Mildly toxic to pets |
| Yellow Groove Bamboo | Direct sun (at least 4-6 hours) | Weekly in the growing season; every 2 weeks when dormant | Pet-safe |
| Yellow Heron's Bill | Direct sun (at least 4-6 hours) | Water sparingly every 10-14 days in summer; keep almost completely dry from late autumn to early spring | Mildly toxic to pets |
| Yellow Ice Plant | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7–14 days in summer; very little supplemental water needed once established | Mildly toxic to pets |
| Yellow Latan Palm | Direct sun (at least 4-6 hours) | When the top 5-8 cm of soil is dry, roughly every 10-14 days in summer; every 3-4 weeks in winter | Pet-safe |
| Yellow Living Rock Cactus | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 21 days in summer; near-dry in winter | Pet-safe |
| Yellow Marliac Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic — crown submerged 15–75 cm (6–30 in) below water surface | Pet-safe |
| Yellow Monanthes | Bright indirect light (just back from a sunny window) | Sparingly; roughly every 2–3 weeks during active growth (autumn–spring), barely at all in summer | Mildly toxic to pets |
| Yellow Monkeyflower | Bright indirect light (just back from a sunny window) | Keep soil permanently wet; never allow to dry out | Pet-safe |
| Yellow Mountain Heath | Bright indirect light (just back from a sunny window) | Regular — keep consistently moist | Mildly toxic to pets |
| Yellow Mountain Saxifrage | Direct sun (at least 4-6 hours) | Every 2–4 days during the growing season; keep consistently moist | Pet-safe |
| Yellow Mussaenda | Direct sun (at least 4-6 hours) | Every 7 days during summer; reduce significantly in winter | Mildly toxic to pets |
| Yellow Oleander | Direct sun (at least 4-6 hours) | Every 5–10 days during establishment; drought-tolerant once established | Toxic to pets |
| Yellow Pimpernel | Medium indirect light (a couple of metres from a window) | High; keep consistently moist | Mildly toxic to pets |
| Yellow Rattle | Direct sun (at least 4-6 hours) | Rain-fed; no supplemental irrigation needed once sown into a meadow | Mildly toxic to pets |
| Yellow Tower Cactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, every 7-14 days in spring and summer; every 4-6 weeks in autumn; once monthly or less in winter | Pet-safe |
| Yellow Trillium | Medium indirect light (a couple of metres from a window) | Regular during spring growing season; reduced once foliage dies back in summer. | Mildly toxic to pets |
| Yellow Trumpet Creeper | Direct sun (at least 4-6 hours) | Every 7–10 days during establishment; drought-tolerant once mature | Mildly toxic to pets |
| Yellow Trumpet Pitcher | Direct sun (at least 4-6 hours) | Keep the growing medium permanently moist using the tray method — 3-5 cm of water in the saucer at all times | Pet-safe |
| Yellow Trumpetbush | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; much less in winter | Mildly toxic to pets |
| Yellow Water Lily | Direct sun (at least 4-6 hours) | Permanently aquatic — crown submerged 15–45 cm (6–18 in) below water surface | Pet-safe |
| Yellow Whitlow Grass | Direct sun (at least 4-6 hours) | Low — allow soil to dry between waterings | Mildly toxic to pets |
| Yellow Whitlowgrass | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; minimal in winter | Pet-safe |
| Yellow Wild Indigo | Direct sun (at least 4-6 hours) | Weekly the first season; rarely thereafter once established | Toxic to pets |
| Yellow Wood Anemone | Medium indirect light (a couple of metres from a window) | Weekly during spring growth; dormant and dry in summer | Toxic to pets |
| Yellow Woodland Violet | Medium indirect light (a couple of metres from a window) | Weekly; maintain evenly moist soil throughout spring and summer | Mildly toxic to pets |
| Yellow-cup Pitcairnia | Bright indirect light (just back from a sunny window) | Keep evenly moist during active growth (spring–autumn); reduce to infrequent watering every 10–14 days in winter, allowing the top half of the substrate to dry. | Mildly toxic to pets |
| Yellow-flowered Sage | Direct sun (at least 4-6 hours) | Every 7-10 days during active growth; very sparingly in winter | Pet-safe |
| Yellow-scaled Tylecodon | Direct sun (at least 4-6 hours) | Every 2–3 weeks during active winter growth; completely dry during summer dormancy | Toxic to pets |
| Yellow-wort | Direct sun (at least 4-6 hours) | Rarely — water only during severe drought | Mildly toxic to pets |
| Yew Bonsai | Bright indirect light (just back from a sunny window) | When the top 2-3 cm is dry, typically every 2-4 days in summer and less in winter | Toxic to pets |
| Yokosca Lady Fern | Low light (north window or shaded room) | Every 2–3 days; keep soil moist to wet | Pet-safe |
| Yokosuka Lady Fern | Medium indirect light (a couple of metres from a window) | Twice weekly during the growing season; reduce in winter | Mildly toxic to pets |
| Yoshino Cherry | Direct sun (at least 4-6 hours) | Water young trees weekly in dry weather; established trees need little | Toxic to pets |
| Young's Weeping Birch | Bright indirect light (just back from a sunny window) | Weekly during establishment and dry spells; every 2 weeks once mature | Pet-safe |
| Yulan Magnolia | Direct sun (at least 4-6 hours) | Weekly when young; established trees need water during prolonged dry spells | Pet-safe |
| Yuletide Sasanqua Camellia | Bright indirect light (just back from a sunny window) | Every 5-7 days in summer; reduce in winter but do not let dry out | Pet-safe |
| Yunnan Cypress | Direct sun (at least 4-6 hours) | Regular during establishment; drought-tolerant once mature | Pet-safe |
| Yunnan Dwarf Palm | Bright indirect light (just back from a sunny window) | Every 7–10 days in summer, monthly in winter | Pet-safe |
| Zamia Palm | Direct sun (at least 4-6 hours) | Every 3–6 weeks | Toxic to pets |
| Zaragoza Ceratozamia | Bright indirect light (just back from a sunny window) | Every 10–14 days in the growing season; every 3–5 weeks in winter | Toxic to pets |
| Zebra Grass | Direct sun (at least 4-6 hours) | Weekly for the first season; every 2–3 weeks once established | Pet-safe |
| Zebrinus Zebra Grass | Direct sun (at least 4-6 hours) | Weekly while establishing, then during dry spells; appreciates steady moisture | Mildly toxic to pets |
| Zephirine Drouhin Rose | Direct sun (at least 4-6 hours) | Deeply once a week in the growing season; more in heat or during establishment | Pet-safe |
| Zigzag Bamboo | Direct sun (at least 4-6 hours) | Weekly in the growing season; fortnightly in winter | Pet-safe |
| Zigzag Clover | Medium indirect light (a couple of metres from a window) | Moderate; tolerates short dry spells once established | Pet-safe |
| Zigzag Goldenrod | Medium indirect light (a couple of metres from a window) | Keep soil consistently moist; water weekly in dry spells | Mildly toxic to pets |
| Zigzag Iris | Medium indirect light (a couple of metres from a window) | Consistently moist to wet | Mildly toxic to pets |
| Zois's Bellflower | Direct sun (at least 4-6 hours) | Low to moderate — water sparingly; allow to nearly dry between waterings | Mildly toxic to pets |
| Zombie Palm | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; every 21–28 days in winter | Pet-safe |
| Zoys's Bellflower | Direct sun (at least 4-6 hours) | Allow soil to dry between waterings; very sparingly in winter | Pet-safe |
| Zulu Spurflower | Medium indirect light (a couple of metres from a window) | Moderate — water twice weekly in containers; less frequently in ground | Mildly toxic to pets |