| 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 |
| Abiu | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out, around every 4-7 days in active growth | Mildly toxic to pets |
| Acer griseum | Direct sun (at least 4-6 hours) | Water deeply weekly while establishing; supplement in summer droughts | 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 |
| Acerola | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days in growth | Mildly toxic to pets |
| 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 |
| 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 |
| Aechmea blanchetiana | Direct sun (at least 4-6 hours) | Keep the central cup filled; refresh weekly and water mix when top few cm are dry | Pet-safe |
| 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 Baobab | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; once a month or less in winter | 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 Mangosteen | Direct sun (at least 4-6 hours) | Water when soil is almost fully dry; established trees tolerate drought. | Mildly toxic to pets |
| African marigold | Direct sun (at least 4-6 hours) | Once or twice weekly; allow top 2–3 cm of soil to dry between waterings | Mildly toxic to pets |
| African Marigold 'Crackerjack' | Direct sun (at least 4-6 hours) | When top 3-4 cm of soil is dry, about every 4-7 days | Mildly toxic to pets |
| African Oil Palm | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 7-10 days in summer; every 14-21 days in winter | Pet-safe |
| African Tamarisk | Direct sun (at least 4-6 hours) | Low once established; moderate during establishment | Pet-safe |
| Afro Hard Rush | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water 1–2 times per week in warm weather | Pet-safe |
| Agapanthus 'Headbourne Hybrids' | Direct sun (at least 4-6 hours) | Weekly through spring and summer growth; reduce sharply once foliage dies back in autumn | Mildly toxic to pets |
| Agapanthus 'Midnight Blue' | Direct sun (at least 4-6 hours) | Weekly while in growth and bud, more in containers; reduce as foliage dies back | Mildly toxic to pets |
| Agapanthus 'Navy Blue' | Direct sun (at least 4-6 hours) | Weekly during active growth and budding; taper off as leaves die back in autumn | Mildly 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 |
| Agapanthus inapertus subsp. pendulus | Direct sun (at least 4-6 hours) | Weekly during active growth and budding; taper off as foliage dies back in autumn | Mildly toxic to pets |
| Agastache 'Black Adder' | 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 |
| 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 angustifolia | Direct sun (at least 4-6 hours) | Every 1-2 weeks in summer when soil is dry, less in winter | Mildly toxic to pets |
| Agave bovicornuta | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth, only when soil is fully dry | Mildly 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 colorata | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth, only when soil is fully 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 difformis | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth when soil is dry, less in winter | Mildly toxic to pets |
| Agave filifera | 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 geminiflora | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and monthly in winter | Mildly toxic to pets |
| Agave guiengola | Direct sun (at least 4-6 hours) | Every 1-2 weeks in summer when soil is dry, less in winter | Mildly toxic to pets |
| Agave havardiana | 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 |
| Agave isthmensis | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and monthly in winter | Toxic to pets |
| Agave lechuguilla | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and rarely in winter | Toxic to pets |
| Agave lophantha | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in summer and monthly or less in winter | Mildly toxic to pets |
| Agave macroacantha | 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 |
| Agave marmorata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in summer and monthly in winter | 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 multifilifera | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and monthly in winter | Toxic to pets |
| Agave nickelsiae | 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 |
| Agave nizandensis | 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 | 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 potatorum | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and 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 stricta | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and rarely in winter | Mildly toxic to pets |
| Agave titanota | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer and rarely 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 |
| Agave-Leaved Sea Holly | Direct sun (at least 4-6 hours) | Low — occasional deep watering during the first season, minimal thereafter | Pet-safe |
| Ageratum houstonianum 'Artist Blue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days | Toxic to pets |
| Ageratum houstonianum 'Blue Horizon' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days | 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 |
| 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 |
| 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 |
| Aleutian mountain heather | Direct sun (at least 4-6 hours) | Consistently moist throughout the growing season; reduce slightly in winter dormancy | 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 |
| 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 |
| Allium schubertii | Direct sun (at least 4-6 hours) | Water lightly in spring growth; keep very dry through summer dormancy, rarely if ever in summer | 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 'Delta Lights' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | 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 'Pink Blush' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | 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 Castillon | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2 weeks in warm growth | 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 Hereroensis | Direct sun (at least 4-6 hours) | When the soil is bone-dry throughout, roughly every 2-3 weeks in summer and monthly or less in winter | Toxic to pets |
| Aloe Humilis | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 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 Longibracteata | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry — roughly every 1-2 weeks in summer, sparingly in winter | Toxic to pets |
| Aloe Massawana | Direct sun (at least 4-6 hours) | When the top 2-4 cm of soil dries — roughly weekly in warm growth, much less in cool months | Toxic to pets |
| Aloe Microstigma | Direct sun (at least 4-6 hours) | When soil is fully dry, about weekly in peak summer heat | Toxic to pets |
| Aloe Minima | Direct sun (at least 4-6 hours) | When soil is dry, roughly every 2 weeks in growth | Toxic to pets |
| Aloe Mitis | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 2-3 weeks in summer | Toxic to pets |
| Aloe Peglerae | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 2-3 weeks in growth | Toxic to pets |
| Aloe Petricola | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 2-3 weeks in summer | Toxic to pets |
| Aloe Pluridens | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 1-2 weeks in summer for an established plant | 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 Suzannae | Direct sun (at least 4-6 hours) | When the soil is dry, roughly every 2 weeks in warm growth and monthly in cool weather | 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 vera | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 2-3 weeks | Toxic to pets |
| Aloe Vera 'Chinese' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of mix is fully dry, roughly every 2-3 weeks in summer | 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 |
| Alphonso Mango | Direct sun (at least 4-6 hours) | Keep evenly moist in growth; water when the top 3-5 cm of soil dries, then withhold before flowering | Mildly toxic to pets |
| Alpine Aster | Direct sun (at least 4-6 hours) | Once per week in dry spells; rainfall usually sufficient when established | Mildly toxic to pets |
| Alpine Balsam | Direct sun (at least 4-6 hours) | Every 7–14 days during growth; reduce after setting seed | 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 Cinquefoil | Direct sun (at least 4-6 hours) | Every 10–14 days; very drought-tolerant once established | Pet-safe |
| 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 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 Puya | Direct sun (at least 4-6 hours) | Moderate in summer, very sparing in winter | 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 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 |
| 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 |
| Ambarella | Direct sun (at least 4-6 hours) | Every 7–10 days; drought-tolerant when established | Pet-safe |
| Amboina Kauri | Direct sun (at least 4-6 hours) | Every 7-10 days when the top few centimetres of soil are dry | 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 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 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 |
| Amethyst Sea Holly | Direct sun (at least 4-6 hours) | Low — water sparingly once established | Mildly toxic to pets |
| Amphibious Bistort | Direct sun (at least 4-6 hours) | Permanent wet soil or shallow water — no irrigation needed once established | Mildly toxic to pets |
| Ananas bracteatus | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, about every 7-10 days in growth, less in winter | Pet-safe |
| Ananas bracteatus 'Tricolor' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in growth | Pet-safe |
| Ananas comosus 'Variegatus' | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, about every 7-10 days in growth, less in winter | Pet-safe |
| Ananas lucidus | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in growth | Pet-safe |
| Ancistrachne uncinulella | 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 |
| Andean Silver-Leaf Sage | Direct sun (at least 4-6 hours) | Allow soil to dry 2–3 cm between waterings | Mildly toxic to pets |
| 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 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 |
| Angel Face Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | 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 Tears Narcissus | Direct sun (at least 4-6 hours) | Moderate during growth; dry during summer dormancy | Toxic to pets |
| Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 1-3 days in peak summer growth; far less when dormant or overwintering | 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 |
| Angelonia angustifolia 'Archangel White' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | Mildly toxic to pets |
| Angelonia angustifolia 'Serenita Raspberry' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | Mildly toxic to pets |
| Angraecum eburneum | Direct sun (at least 4-6 hours) | When the substrate is almost completely dry, roughly every 5-7 days year-round | Mildly toxic to pets |
| 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 Clary | Direct sun (at least 4-6 hours) | Every 7–10 days | Mildly toxic to pets |
| Annual Phlox | Direct sun (at least 4-6 hours) | Every 5–7 days; keep soil evenly moist but not saturated | Pet-safe |
| 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 |
| Annual Rainbow Plant | Direct sun (at least 4-6 hours) | Keep medium wet at all times; tray method, water never allowed to dry out | Pet-safe |
| Antigonon leptopus | Direct sun (at least 4-6 hours) | Water regularly while establishing, then only in prolonged drought | Mildly toxic to pets |
| 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 |
| Aponogeton distachyos | Direct sun (at least 4-6 hours) | Permanently submerged; maintain a stable pond water level | Mildly toxic to pets |
| Appalachian Blazing Star | Direct sun (at least 4-6 hours) | Every 2 weeks during establishment; essentially rain-fed once mature | Pet-safe |
| Apricot Sprite Hyssop | Direct sun (at least 4-6 hours) | Every 7–10 days once established; more frequent in containers | Pet-safe |
| 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 |
| Arabian Desert Rose | Direct sun (at least 4-6 hours) | Every 7–14 days in active growth (spring–summer); minimal in winter dormancy | Toxic to pets |
| Arabian Jasmine | Direct sun (at least 4-6 hours) | Keep evenly moist in growth; water when the top 2-3 cm of soil dries, often every 3-5 days in warmth | Pet-safe |
| Araca-boi Sapote | Direct sun (at least 4-6 hours) | Every 4–7 days; keep soil consistently moist | 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 |
| Argentine Giant Cactus | Direct sun (at least 4-6 hours) | When the soil is dry, about every 1-2 weeks in summer; keep dry in winter | Pet-safe |
| 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 |
| Arikury Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days | Pet-safe |
| 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 |
| Armenian Speedwell | Direct sun (at least 4-6 hours) | Every 10–14 days during the growing season; little to none in winter. | 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 |
| Arroyo Lupine | Direct sun (at least 4-6 hours) | Low once established; rely on winter rainfall; supplement lightly in February–March during dry years | Toxic to pets |
| Ashanti Blood | Direct sun (at least 4-6 hours) | Every 5–7 days during growing season; reduce in dormancy | Mildly 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 |
| Ashy Sunflower | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; very drought-tolerant | Pet-safe |
| Assai Palm | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 3-5 days in warm weather | Pet-safe |
| Assam Fan Palm | Direct sun (at least 4-6 hours) | Weekly in growing season, every 2–3 weeks in winter | 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 'October Skies' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days once established | Pet-safe |
| 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 'Raydon's Favorite' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days once established | Pet-safe |
| 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 |
| Astrophytum coahuilense | Direct sun (at least 4-6 hours) | Soak-and-dry, roughly every 14 days in summer; keep dry in winter | Pet-safe |
| Ataulfo Mango | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries in growth; withhold before flowering | Mildly toxic to pets |
| Atemoya | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm dries; keep steady during fruiting | Mildly toxic to pets |
| Atlantic White Cedar | Direct sun (at least 4-6 hours) | Constant moisture; tolerates standing water seasonally | 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 |
| Audray White globe amaranth | Direct sun (at least 4-6 hours) | Every 5–7 days; drought-tolerant once established | Pet-safe |
| 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 |
| 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 | 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 Foxtail Cycad | Direct sun (at least 4-6 hours) | When the top 5 cm of mix is dry, roughly every 12-16 days in growth | Toxic to pets |
| Autumn Brilliance serviceberry | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once established | Pet-safe |
| Autumn Cascades Tupelo | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| Autumn Catchfly | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; reduce in winter | Pet-safe |
| Autumn Crocus | Direct sun (at least 4-6 hours) | Low — naturally rainfall-dependent; needs dry summer dormancy | Mildly 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 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 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 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 red grass | Direct sun (at least 4-6 hours) | Every 7–14 days during the growing season; reduce in autumn and winter | Pet-safe |
| 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 |
| 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 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 |
| Baboon Flower | Direct sun (at least 4-6 hours) | Regular during growth and flowering, dry during summer dormancy | 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 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 |
| Bacon Avocado | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, roughly every 5-7 days in warm growth | Toxic to pets |
| Bacuri | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-8 days in growth | Mildly toxic to pets |
| 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 |
| Baker's Tulip | Direct sun (at least 4-6 hours) | Moderate in spring; dry in summer | Toxic to pets |
| Balbis Banana | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 3-5 days in summer | Pet-safe |
| 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 Saxifrage | Direct sun (at least 4-6 hours) | Low — water at the base only; allow near-drying between waterings | Pet-safe |
| Ball Cactus | Direct sun (at least 4-6 hours) | When the top of the soil is dry, about every 7-10 days in summer; sparingly to none 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 |
| Bamboo Muhly | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly or less in winter once established | Pet-safe |
| 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 |
| 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 |
| Baron's Pachypodium | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; none from late autumn to mid-spring | Toxic to pets |
| Barrelier's Sage | Direct sun (at least 4-6 hours) | Weekly to establish, then fortnightly | Pet-safe |
| Barter's Cycad | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; every 4–6 weeks in winter | Toxic to pets |
| Basil-Leaved Sun Rose | Direct sun (at least 4-6 hours) | Very low — minimal supplemental irrigation needed once established | Mildly toxic to pets |
| 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 |
| Batalin's Tulip | Direct sun (at least 4-6 hours) | Light to moderate in spring; completely dry in summer | Toxic to pets |
| Beach Cabbage | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant once established | Mildly toxic to pets |
| Bearberry Cotoneaster | Direct sun (at least 4-6 hours) | Fortnightly once established; more frequent for the first growing season | Mildly toxic to pets |
| 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 |
| Beatrice Watsonia | Direct sun (at least 4-6 hours) | Regular throughout growing season; reduce but do not dry out in winter | Mildly toxic to pets |
| Beaucarnea Stricta | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer and much less in winter | Pet-safe |
| beautiful feather grass | Direct sun (at least 4-6 hours) | Weekly in the first season; minimal once established | 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 |
| Beautiful Sea Holly | Direct sun (at least 4-6 hours) | Low — water sparingly once established | Mildly toxic to pets |
| Beavertail Cactus | Direct sun (at least 4-6 hours) | Very sparingly when soil is bone dry, roughly every 3-4 weeks in summer; keep dry in winter | 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 |
| 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 |
| Bell heather | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2–3 weeks once established | Pet-safe |
| Bell Heather C.D. Eason | Direct sun (at least 4-6 hours) | Moderate; water during dry spells, avoid waterlogging | Mildly 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 |
| Benary's Giant Coral zinnia | Direct sun (at least 4-6 hours) | Regular; water at soil level 2–3 times per week in dry weather | Pet-safe |
| Benary's Giant Coral Zinnia | Direct sun (at least 4-6 hours) | Water at the base every 5-7 days, allowing the top 3-5 cm of soil to dry between waterings; overhead watering should be avoided | Pet-safe |
| Bent Alligator Flag | Direct sun (at least 4-6 hours) | Permanent standing water or saturated soil; up to 30 cm over roots | Mildly toxic to pets |
| Bent Alligator Flag | Direct sun (at least 4-6 hours) | Aquatic marginal — roots permanently in shallow water or waterlogged soil | Mildly toxic to pets |
| Beoley Gold heather | Direct sun (at least 4-6 hours) | Weekly during establishment; occasional watering once established in dry spells | Pet-safe |
| 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 |
| Besom heath | Direct sun (at least 4-6 hours) | Weekly during establishment; largely self-sufficient once established | Pet-safe |
| 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 |
| Beuvron Dwarf Scots Pine | Direct sun (at least 4-6 hours) | Every 10–14 days in summer during the first 3 years; largely self-sufficient once established | 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 |
| Bidens ferulifolia 'Bidy Gonzales' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in containers during summer heat | Pet-safe |
| Bidens ferulifolia 'Campfire Fireburst' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 2-4 days in summer containers | Pet-safe |
| Big Bluestem | Direct sun (at least 4-6 hours) | Every 2–3 weeks during establishment; rainfall-sufficient once established in most of its native range | Pet-safe |
| 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-Flowered Catmint | Direct sun (at least 4-6 hours) | Every 7–10 days; allow soil surface to dry between waterings | Pet-safe |
| Bigcone Douglas Fir | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established | Pet-safe |
| Bignay | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 4-7 days in growth | Mildly toxic to pets |
| Bilimbi | Direct sun (at least 4-6 hours) | Every 3-7 days, keeping soil consistently moist; bilimbi dislikes drying out | Toxic to pets |
| 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 of paradise | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, every 7-10 days | Toxic to pets |
| Bird of Paradise | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | 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 Spruce | Direct sun (at least 4-6 hours) | Moderate; water during dry spells in the first two years, then largely self-sufficient | Pet-safe |
| Biriba | Direct sun (at least 4-6 hours) | 2–3 times per week; do not allow soil to dry out | Pet-safe |
| 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 |
| Bitterroot | Direct sun (at least 4-6 hours) | Winter rains / early spring only; bone dry from June to October | 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 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 Medick | Direct sun (at least 4-6 hours) | Low to moderate | Pet-safe |
| Black Oak | Direct sun (at least 4-6 hours) | Rainfall-dependent once established; moderate supplemental irrigation in year 1–2 | Mildly toxic to pets |
| Black Olive Bonsai | 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 |
| Black Prince Echeveria | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| 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) | Every 1–2 weeks autumn to spring; minimal in summer dormancy | Mildly toxic to pets |
| 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 Sapote | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-9 days in growth | Mildly toxic to pets |
| Black Spruce | Direct sun (at least 4-6 hours) | Consistent moisture; tolerates waterlogging — does not dry out between waterings | 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-eyed Susan vine | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days in summer | Mildly toxic to pets |
| Black-Eyed Susan Vine | 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 | Pet-safe |
| Black-Headed Fountain Grass | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2 weeks once established | 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 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 |
| 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 Ambition Blue Grama | Direct sun (at least 4-6 hours) | Water through the first growing season, then only in severe drought, every 2-3 weeks at most | Mildly toxic to pets |
| Blood Banana | Direct sun (at least 4-6 hours) | Roughly weekly in active growth; every 10-14 days in winter | Pet-safe |
| Blood-Cupped Pink | Direct sun (at least 4-6 hours) | Infrequent; highly drought-tolerant once established | Mildly toxic to pets |
| Blood-red trumpet vine | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established. | Mildly toxic to pets |
| 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 Bird Rose of Sharon | Direct sun (at least 4-6 hours) | Weekly during dry spells; reduce once established | 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 Chalksticks | Direct sun (at least 4-6 hours) | Roughly every 2-3 weeks in spring and summer; about once a month or less in winter. | Toxic to pets |
| Blue China Fir | Direct sun (at least 4-6 hours) | Regular when young; moderate once established | Mildly 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 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 dawn flower | Direct sun (at least 4-6 hours) | Once or twice weekly during dry periods; established plants are relatively drought-tolerant | Toxic to pets |
| 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 Grama Grass | Direct sun (at least 4-6 hours) | Water to establish in the first season; thereafter only in extreme drought, roughly every 2-3 weeks if at all | Mildly toxic to pets |
| Blue Hair Grass | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; water sparingly | 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 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 Latan Palm | Direct sun (at least 4-6 hours) | Every 7–10 days in growing season; less in winter | Pet-safe |
| Blue Latan Palm | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | Pet-safe |
| 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 Melon Cactus | 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 3-4 weeks in winter | Pet-safe |
| 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 Morning Glory | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in warm weather | Toxic to pets |
| Blue Oat Grass | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Blue Oat Grass | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then occasionally | Mildly toxic to pets |
| Blue Pacific Shore Juniper | Direct sun (at least 4-6 hours) | Low — very drought and salt tolerant once established | 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 Rug Juniper | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | 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 Star Juniper | Direct sun (at least 4-6 hours) | Water through the first season; afterward only in prolonged dry spells | Toxic to pets |
| Blue Star Water Lily | Direct sun (at least 4-6 hours) | Continuously aquatic — grow in still or slow-moving water 6–18 in (15–45 cm) deep. | Mildly toxic to pets |
| Blue Star Water Lily | Direct sun (at least 4-6 hours) | Fully aquatic; roots and tuber submerged, leaves and flowers floating or emergent | Mildly 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 Torch Cactus | Direct sun (at least 4-6 hours) | When the mix is fully dry, about every 2-3 weeks in summer; nearly none in winter | Mildly 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 Vanda | Direct sun (at least 4-6 hours) | Daily in warm months when roots silver over; every 2-3 days in cool, dim weather | Pet-safe |
| 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 Water Lily | Direct sun (at least 4-6 hours) | Aquatic — submerged in warm still water permanently | 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-green Adenia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; withhold entirely in winter dormancy | 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 |
| Boat Orchid | Direct sun (at least 4-6 hours) | When the mix is dry, roughly every 7-10 days, less in winter | Pet-safe |
| 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 |
| Bog Sage | Direct sun (at least 4-6 hours) | Moderate to high — keep soil consistently moist | Mildly toxic to pets |
| Boissier's Silverbush | Direct sun (at least 4-6 hours) | Very infrequent once established | Mildly 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 |
| 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 |
| 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 |
| Bonsai Pachypodium | Direct sun (at least 4-6 hours) | Every 14–21 days in summer; none or barely any in winter dormancy | Toxic to pets |
| 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 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 | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out | Mildly toxic to pets |
| Bougainvillea 'Barbara Karst' | Direct sun (at least 4-6 hours) | Deeply but infrequently, only when the top 5 cm of soil is dry, roughly every 7-14 days | Pet-safe |
| 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 'Raspberry Ice' | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 5-10 days | Pet-safe |
| Bougainvillea 'San Diego Red' | Direct sun (at least 4-6 hours) | Deep soak only when the top 5 cm of soil dries, about every 7-14 days | Pet-safe |
| 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 |
| Bowl Lotus | Direct sun (at least 4-6 hours) | Keep submerged at all times; never allow the rhizome to dry out | Pet-safe |
| Bowles Golden Sedge | Direct sun (at least 4-6 hours) | Keep wet to constantly moist; never allow to dry out | 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 |
| Bradbury's Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; rarely in winter | Mildly toxic to pets |
| 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 |
| Brandy Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season | Pet-safe |
| Brassavola cucullata | Direct sun (at least 4-6 hours) | Water thoroughly, then let it dry out almost completely before watering again | Mildly toxic to pets |
| Brazilian Jasmine | Direct sun (at least 4-6 hours) | Let the top 2-3 cm of soil dry, then water; roughly every 4-7 days, more often in heat | Mildly toxic to pets |
| Breadfruit | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water deeply 2-3 times a week in active growth | Mildly toxic to pets |
| Breadnut | Direct sun (at least 4-6 hours) | Water young trees 2–3 times per week; established trees are moderately drought tolerant but benefit from weekly deep irrigation in dry seasons. | 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 |
| Brewer Spruce | Direct sun (at least 4-6 hours) | Moderate — water regularly during establishment; tolerates summer drought once established | Pet-safe |
| Brewer's Weeping Spruce | Direct sun (at least 4-6 hours) | Deeply every 7–10 days in summer; reduce in winter but do not allow soil to fully dry | Mildly 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 Bouquet Plumeria | Direct sun (at least 4-6 hours) | Every 7–10 days in active growth; reduce to every 3–4 weeks in cooler months | 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 |
| Bright Bikinis strawflower | Direct sun (at least 4-6 hours) | Every 5–7 days; allow soil to dry slightly between waterings | Mildly toxic to pets |
| Bright Bikinis Strawflower | 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 |
| Brilliant Hibiscus | Direct sun (at least 4-6 hours) | Regularly during growth; reduce in winter | Mildly toxic to pets |
| Brilliantissima red chokeberry | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once established | 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 |
| 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 |
| 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-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 Pondweed | Direct sun (at least 4-6 hours) | Fully submerged aquatic; grows in 30 cm to 150 cm of water | Pet-safe |
| Broad-Leaved Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established | 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 |
| Broadway's Melon Cactus | 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 weeks in winter | Pet-safe |
| 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 |
| Broomsedge Bluestem | Direct sun (at least 4-6 hours) | Rainfall sufficient; no supplemental irrigation needed once established | 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 |
| 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-tipped Bursera | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; withhold almost entirely in winter dormancy | Mildly toxic to pets |
| 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 |
| Buckley's Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; very little in winter | Mildly toxic to pets |
| 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 Hand Citron | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, typically every 5-10 days | 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 Lily | Direct sun (at least 4-6 hours) | Regular during growth; reduce in winter | Mildly toxic to pets |
| Buining's Uebelmannia | 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 every 4-6 weeks or less in winter | 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 Buttercup | Direct sun (at least 4-6 hours) | Once weekly or less; drought-tolerant once established | Toxic to pets |
| Bulbous Trichodiadema | Direct sun (at least 4-6 hours) | Every 2–3 weeks during spring and summer; once a month or less in winter | Pet-safe |
| 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 |
| Bunny ears cactus | Direct sun (at least 4-6 hours) | When the compost is fully dry, roughly every 2-3 weeks in spring and summer | Pet-safe |
| 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 |
| Burkwood Viburnum | Direct sun (at least 4-6 hours) | Water when the top 5 cm of soil dries, roughly weekly during establishment | Pet-safe |
| Burmese Grape | Direct sun (at least 4-6 hours) | Regular watering; 2–3 times per week; do not let soil dry out completely | Mildly toxic to pets |
| Burnet Rose | Direct sun (at least 4-6 hours) | Weekly during establishment; rarely once mature | Pet-safe |
| Bush Allamanda | Direct sun (at least 4-6 hours) | Every 5–7 days in the growing season; reduce to every 10–14 days in winter | Toxic to pets |
| 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 |
| 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 |
| Butia Yatay | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 10-14 days while establishing, sparingly once mature | Mildly toxic to pets |
| Butomus umbellatus | Direct sun (at least 4-6 hours) | Constantly wet; shallow margin | Mildly toxic to pets |
| Butt's bougainvillea | Direct sun (at least 4-6 hours) | Every 7–10 days in active growth; reduce significantly to trigger blooming | Mildly toxic to pets |
| 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 Gladiolus | Direct sun (at least 4-6 hours) | Regular during active growth (summer–autumn); reduce as foliage dies; dry rest in winter | 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 |
| Buttonhole Orchid | Direct sun (at least 4-6 hours) | When the top of the mix dries, roughly every 5-9 days | Pet-safe |
| Buttonwood Bonsai | Direct sun (at least 4-6 hours) | When the top of the soil starts to dry, often daily in heat | Mildly toxic to pets |
| Byzantine Gladiolus | Direct sun (at least 4-6 hours) | Moderate during spring growth; minimal in summer after dormancy | Toxic to pets |
| C.D. Eason bell heather | Direct sun (at least 4-6 hours) | Weekly while establishing; every 2–3 weeks once settled | Pet-safe |
| Cabada Palm | Direct sun (at least 4-6 hours) | Every 3–5 days when young; drought-tolerant once established | Pet-safe |
| Cabbage Palm | Direct sun (at least 4-6 hours) | Infrequent once established, when the top several centimetres are dry, roughly every 1-2 weeks | Mildly toxic to pets |
| Cacti (general care) | Direct sun (at least 4-6 hours) | Soak when the mix is bone dry — roughly every 2-4 weeks in summer | Pet-safe |
| Cadiz Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the growing season; very rarely in winter | Mildly toxic to pets |
| Café au Lait Dahlia | Direct sun (at least 4-6 hours) | 2–3 times per week | 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 |
| Calibrachoa 'Cabaret Deep Blue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, often daily in summer baskets | Pet-safe |
| Calibrachoa 'MiniFamous Double Amethyst' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, often daily in hot weather | Pet-safe |
| Calibrachoa 'Superbells Lemon Slice' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, often daily in baskets during summer heat | Pet-safe |
| Calibrachoa 'Superbells Trailing Blue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, frequently daily in summer baskets | Pet-safe |
| 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 Barrel Cactus | Direct sun (at least 4-6 hours) | Every 2-4 weeks in active growth; none in winter | Mildly toxic to pets |
| California Fan Palm | Direct sun (at least 4-6 hours) | Deeply but infrequently, every 10-14 days once established; more while young | Mildly toxic to pets |
| 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 poppy | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; more frequent during germination | Mildly toxic to pets |
| 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 |
| 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 |
| 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 |
| 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 |
| Campfire Crassula (Red Pagoda) | Direct sun (at least 4-6 hours) | Every 1-2 weeks in spring-summer; roughly monthly in winter | Mildly toxic to pets |
| 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 |
| Canary Island Date Palm | Direct sun (at least 4-6 hours) | Every 7-10 days in summer; roughly every 2-3 weeks in winter | Pet-safe |
| Canary Island Lavender | Direct sun (at least 4-6 hours) | Every 2 weeks in the growing season; sparingly in winter | 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 Island Sea Lavender | Direct sun (at least 4-6 hours) | Every 1–2 weeks in growth; monthly in winter | Pet-safe |
| Candelabra Euphorbia | Direct sun (at least 4-6 hours) | When the mix is completely dry, about every 2-3 weeks in summer | 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 |
| 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 |
| Canistel | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-9 days in growth | Mildly toxic to pets |
| Canna 'Bengal Tiger' | Direct sun (at least 4-6 hours) | Water every 2-3 days in summer to keep soil consistently moist | Mildly toxic to pets |
| Canna 'Black Knight' | Direct sun (at least 4-6 hours) | Keep evenly moist throughout the growing season, watering every 2-4 days depending on temperature | Mildly toxic to pets |
| Canna 'Cleopatra' | Direct sun (at least 4-6 hours) | Water regularly to maintain consistently moist soil, approximately every 2-3 days in warm weather | Mildly toxic to pets |
| Canna 'Durban' | Direct sun (at least 4-6 hours) | Water regularly to keep soil evenly moist, roughly every 2-3 days in summer heat | Mildly toxic to pets |
| Canna 'Pacific Beauty' | Direct sun (at least 4-6 hours) | Water every 2-3 days to keep the soil consistently moist during the growing season | Mildly toxic to pets |
| Canna 'Phasion' | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 2-3 days in warm weather, more often in containers | Mildly toxic to pets |
| Canna 'Pink Sunburst' | Direct sun (at least 4-6 hours) | Keep evenly moist throughout the growing season, watering every 2-3 days or whenever the top few centimetres become dry | Mildly toxic to pets |
| Canna 'Pretoria' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times per week during the growing season; reduce sharply once foliage dies back in autumn | Mildly toxic to pets |
| Canna 'Red King Humbert' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times per week in summer; reduce once foliage begins to die back in autumn | Mildly toxic to pets |
| Canna 'Roi Humbert' | Direct sun (at least 4-6 hours) | Keep soil consistently moist, watering every 2-3 days in warm weather or whenever the top 2-3 cm dries out | Mildly toxic to pets |
| Canna 'Striped Beauty' | Direct sun (at least 4-6 hours) | Water every 2-4 days to maintain moist (not soggy) soil throughout the growing season | Mildly toxic to pets |
| Canna 'The President' | Direct sun (at least 4-6 hours) | Water every 2-3 days in summer to maintain evenly moist soil | Mildly toxic to pets |
| Canna 'Tropicanna' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times per week during summer; reduce watering once plants go dormant in autumn | Mildly toxic to pets |
| Canna 'Wyoming' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times per week during summer; taper off in autumn as growth slows | Mildly toxic to pets |
| Canna 'Yellow King Humbert' | Direct sun (at least 4-6 hours) | Water every 2-3 days to maintain consistently moist soil during the growing season | Mildly toxic to pets |
| Cantabrian Draba | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | 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 Clubfoot | Direct sun (at least 4-6 hours) | Every 14–21 days in summer; once monthly or less in winter | 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 Gold Everlasting | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; 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 |
| Capped Catasetum | Direct sun (at least 4-6 hours) | Abundant daily to every-other-day during growth; dry rest in winter | Pet-safe |
| 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 |
| Caralluma europaea | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer; keep nearly dry October-March | Mildly toxic to pets |
| Caralluma hesperidum | Direct sun (at least 4-6 hours) | When soil is bone-dry, about every 10-14 days in active growth; keep nearly dry in winter | Mildly toxic to pets |
| Caralluma speciosa | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 7-12 days in summer heat; minimal water in winter | Mildly toxic to pets |
| 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 |
| Cardboard Cycad | Direct sun (at least 4-6 hours) | When the soil is dry well down, roughly every 12-16 days in growth | Toxic to pets |
| Cardinal climber | Direct sun (at least 4-6 hours) | Once or twice a week; approximately 2.5 cm (1 in) per week | Toxic to pets |
| Cardinal Royal rowan | Direct sun (at least 4-6 hours) | Regular during the first season; drought-tolerant once established | Mildly toxic to pets |
| 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 riparia 'Variegata' | Direct sun (at least 4-6 hours) | Keep wet to shallowly submerged at all times | Mildly toxic to pets |
| Caribbean Royal Palm | Direct sun (at least 4-6 hours) | Twice weekly when young; established trees weekly or as needed | Pet-safe |
| Caribbean Royal Palm | Direct sun (at least 4-6 hours) | When the top 4-6 cm of soil is dry, roughly every 7-10 days in the growing season; every 14-21 days in drier winter months | Pet-safe |
| 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 |
| Carob | Direct sun (at least 4-6 hours) | When soil is dry well below the surface, every 1-3 weeks once established | 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 Queen Lotus | Direct sun (at least 4-6 hours) | Permanently submerged; maintain 5–15 cm (2–6 in) of water over the soil surface for established plants | 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 |
| Carpentaria Palm | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in warm weather | Pet-safe |
| Carrion Flower (Stapelia gigantea) | Direct sun (at least 4-6 hours) | Every 2-3 weeks in active growth (spring-autumn); keep nearly dry in winter | 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 |
| Cas Guava | Direct sun (at least 4-6 hours) | Water deeply 2–3 times per week in the growing season; reduce to once weekly in winter. | Pet-safe |
| Cascade Purple Aubrieta | Direct sun (at least 4-6 hours) | Weekly during active growth; minimal in summer dormancy | Pet-safe |
| Cascadia trailing petunia | Direct sun (at least 4-6 hours) | Every 2-3 days in warm weather; check daily in summer heat | Pet-safe |
| Case's Ixora | Direct sun (at least 4-6 hours) | Every 2-3 days during warm months, reduce to weekly in cooler weather | Mildly 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 | 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 |
| Catesby's Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method with seasonal reduction | Pet-safe |
| Catharanthus roseus 'Cora Cascade Strawberry' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days | Toxic to pets |
| Catharanthus roseus 'Titan Polka Dot' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-10 days | 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 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 |
| Cavendish Banana | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water when the top 2-3 cm dries, often every 2-4 days in active growth | Pet-safe |
| 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 Bay Cherry | Direct sun (at least 4-6 hours) | Water established plants once or twice per week; newly planted specimens require daily watering for the first 4–6 weeks. | 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 |
| Celadine Frangipani | Direct sun (at least 4-6 hours) | Every 7–14 days in growth; reduce sharply in autumn; minimal in winter | Toxic to pets |
| Celosia (cockscomb) | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| Celosia argentea var. cristata 'Chief Mix' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days | Pet-safe |
| Celosia argentea var. plumosa 'Fresh Look Yellow' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days | Pet-safe |
| Celosia argentea var. spicata 'Cramer's Amazon' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-6 days once established | Pet-safe |
| 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 |
| Century Yellow Feather Celosia | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | 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 |
| 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 |
| Chalice Vine | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce in winter | Toxic to pets |
| 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 |
| 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 |
| Chamomile | Direct sun (at least 4-6 hours) | When the top of the soil is dry, every 7-10 days | Toxic to pets |
| 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 |
| 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 |
| Charming Puya | Direct sun (at least 4-6 hours) | Occasionally in summer, minimally in winter | Mildly toxic to pets |
| 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 |
| Chempedak | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply 2-3 times weekly in warm growth | Mildly toxic to pets |
| Cherapu | Direct sun (at least 4-6 hours) | Daily in dry periods; every 2–3 days with regular rainfall | Mildly toxic to pets |
| Cherimoya | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm dries during growth; reduce in dormancy | Mildly toxic to pets |
| Cherry Brandy Rudbeckia | 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 |
| 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 |
| Cherry of the Río Grande | Direct sun (at least 4-6 hours) | Water thoroughly 2–3 times per week in summer; reduce to once every 7–10 days in winter. | Pet-safe |
| 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 |
| 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 Jasmine | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days in summer | Mildly toxic to pets |
| Chilean Sheep-eating Plant | Direct sun (at least 4-6 hours) | Sparingly — monthly or less in winter, once every 2–3 weeks in summer | Mildly toxic to pets |
| 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 |
| China aster | Direct sun (at least 4-6 hours) | 2–3 times per week in warm weather; once per week in cool conditions | 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 pink | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; reduce in cool weather | Mildly toxic to pets |
| Chincherinchee | Direct sun (at least 4-6 hours) | Regularly during active growth; dry or minimal during summer dormancy | Toxic to pets |
| Chinese Arborvitae | Direct sun (at least 4-6 hours) | Moderate — water regularly until established; drought-tolerant once established | Pet-safe |
| 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 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 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 Honeysuckle | Direct sun (at least 4-6 hours) | Every 3–5 days during the growing season; reduce in cooler months | Mildly toxic to pets |
| 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 Juniper | Direct sun (at least 4-6 hours) | Low to moderate; water regularly until established, then drought-tolerant | 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 Peony 'Sarah Bernhardt' | Direct sun (at least 4-6 hours) | Deeply once or twice a week during dry spells; reduce after foliage dies back | 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 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 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 |
| Chionodoxa luciliae | Direct sun (at least 4-6 hours) | Rainfall in most settings; rarely needs watering | Mildly toxic to pets |
| Chive-Leaved Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; minimal in winter | Mildly toxic to pets |
| Chocolate Cosmos | Direct sun (at least 4-6 hours) | Keep evenly moist through summer; water roughly weekly, more in heat, less once dormant | 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 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 Palm | Direct sun (at least 4-6 hours) | Every 5–7 days; allow top 2–3 cm of soil to dry between waterings | Pet-safe |
| Christmas Palm | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days in warmth | Pet-safe |
| 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 | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in active growth | Toxic to pets |
| 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 |
| 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 |
| 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 Bunny Ears | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 2-3 weeks in summer; nearly dry in winter | Pet-safe |
| 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 |
| 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 |
| Cleft Phlox | Direct sun (at least 4-6 hours) | Every 10–14 days when establishing; monthly once established in dry periods | Pet-safe |
| 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 |
| Cleistocactus Hyalacanthus | Direct sun (at least 4-6 hours) | When the mix is fully dry, about every 7-10 days in summer; keep dry 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 '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 '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 '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 '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 '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 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 |
| Cleveland Sage | Direct sun (at least 4-6 hours) | Very infrequent after establishment — once monthly or less in summer | Pet-safe |
| 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 |
| 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 Iceberg Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week in the growing season, more during heat | 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 |
| Clustered bellflower | Direct sun (at least 4-6 hours) | Weekly during dry spells; moderate water needs | 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 Freesia | Direct sun (at least 4-6 hours) | Moderate during growth; reduce to dry after dormancy | Pet-safe |
| 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 |
| 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 |
| 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 |
| Cobra Lily | Direct sun (at least 4-6 hours) | Keep constantly damp to wet, year-round | Pet-safe |
| 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 |
| Cockscomb | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-6 days in summer | Pet-safe |
| Coconut Palm | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 3-5 days in heat, never letting it dry out fully | Pet-safe |
| Colocasia 'Coffee Cups' | Direct sun (at least 4-6 hours) | Keep constantly wet; never let it dry out | Toxic to pets |
| Colocasia Black Coral | Direct sun (at least 4-6 hours) | Keep soil constantly moist; water every 2-4 days, daily in peak summer | Toxic to pets |
| Colocasia Burgundy Stem | Direct sun (at least 4-6 hours) | Keep constantly moist to wet; water whenever the surface starts to dry | Toxic to pets |
| Colocasia Colocasia Gigantea Thailand Giant | Direct sun (at least 4-6 hours) | Keep constantly moist to wet; water daily in heat, or stand in shallow standing water | Toxic to pets |
| Colocasia Crown of Tonga | Direct sun (at least 4-6 hours) | Keep constantly moist to boggy; check every 1-3 days in heat, never letting it dry out | Toxic to pets |
| Colocasia Illustris Black Runner | Direct sun (at least 4-6 hours) | Keep constantly moist; water daily in heat, or stand in 2-5 cm of standing water | Toxic to pets |
| Colocasia Tea Cup | Direct sun (at least 4-6 hours) | Keep soil constantly moist; water every 2-4 days, daily in summer | Toxic to pets |
| Colorado Blue Spruce | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; regular deep watering in first 2–3 years | Mildly 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 |
| Columnae Snow-in-Summer | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Columnar Douglas Fir | Direct sun (at least 4-6 hours) | Moderate during establishment; reduced once established | Pet-safe |
| 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 |
| Comb Speedwell | Direct sun (at least 4-6 hours) | Every 2–3 weeks; very drought-tolerant | Pet-safe |
| Comb-Spined Uebelmannia | 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; reduce to once every 5-6 weeks in winter | Pet-safe |
| 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 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 Broom | Direct sun (at least 4-6 hours) | sparingly after establishment | 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 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 Evening Primrose | Direct sun (at least 4-6 hours) | Every 10–14 days; highly tolerant of drought once established | Pet-safe |
| 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 Gorse | Direct sun (at least 4-6 hours) | rarely after establishment | 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 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 immortelle | Direct sun (at least 4-6 hours) | Every 7–10 days; allow soil to dry between waterings | Pet-safe |
| Common Ironweed | Direct sun (at least 4-6 hours) | Moderate to high — keep soil moist | Mildly 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 Juniper | Direct sun (at least 4-6 hours) | Low; water deeply but infrequently once established | Mildly toxic to pets |
| Common Knapweed | Direct sun (at least 4-6 hours) | Low — water only to establish | Mildly toxic to pets |
| 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 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 peony | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce after bloom | Mildly toxic to pets |
| Common Peony 'Rubra Plena' | Direct sun (at least 4-6 hours) | Deeply once or twice a week during dry spring and summer weather; minimal watering once dormant | Toxic to pets |
| 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 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 Sea Lavender | Direct sun (at least 4-6 hours) | Low to moderate — drought-tolerant once established; tolerates periodic waterlogging | Pet-safe |
| 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 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 Toadflax | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established; water only in the first season | Mildly toxic to pets |
| Common tobacco | Direct sun (at least 4-6 hours) | Every 3–5 days; maintain consistently moist soil | Toxic to pets |
| Common Tussock Grass | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; tolerates extended dry periods | 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 Hyacinth | Direct sun (at least 4-6 hours) | Aquatic — free-floating on the water surface permanently | Pet-safe |
| 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 Alpine Fir | Direct sun (at least 4-6 hours) | Moderate; regular when establishing, low to moderate once established | Mildly toxic to pets |
| Compact Gem Bosnian Pine | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| 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 White Fir | Direct sun (at least 4-6 hours) | Moderate; water regularly when young; drought tolerant once established | Mildly toxic to pets |
| 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 |
| Concrete Leaf | Direct sun (at least 4-6 hours) | Sparingly; every 1-2 weeks in active growth (autumn/spring), nearly dry in summer and winter | Mildly toxic to pets |
| 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 |
| Confederate Rose | Direct sun (at least 4-6 hours) | Regularly during growth; deeply once or twice per week | Mildly toxic to pets |
| Congo Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks (growing season); monthly or less in winter | Toxic to pets |
| 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 |
| Consolea Moniliformis | Direct sun (at least 4-6 hours) | When the mix is fully dry, about every 1-2 weeks in summer; sparse in winter | 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 |
| 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 |
| Coppertone Stonecrop | Direct sun (at least 4-6 hours) | Every 1-2 weeks in spring/summer; roughly monthly in winter | Pet-safe |
| Coquimbo Copiapoa | Direct sun (at least 4-6 hours) | Every 14-21 days in summer; once a month or less in winter | Pet-safe |
| Cora XDR vinca | Direct sun (at least 4-6 hours) | Every 4–7 days once established; water young transplants more frequently | Toxic to pets |
| 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 Lily | Direct sun (at least 4-6 hours) | When top 2–3 cm of soil is dry | Toxic to pets |
| Coral Plant | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; every 3–4 weeks in winter | Toxic to pets |
| 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 3-5 cm of soil is dry; weekly to establish, then sparingly | 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 'Ruby 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 '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 |
| Corn Marigold | Direct sun (at least 4-6 hours) | Low to moderate — water only in dry spells | 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 |
| Cornflower | Direct sun (at least 4-6 hours) | Low to moderate — water during establishment only | Pet-safe |
| Cornish heath | Direct sun (at least 4-6 hours) | Weekly while establishing; every 2–3 weeks once settled | 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 |
| Corsican Heath | Direct sun (at least 4-6 hours) | Moderate; water occasionally once established | 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 |
| Coryphantha macromeris | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 10-14 days in growth; keep dry in winter | Pet-safe |
| Coryphantha vivipara | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 10-14 days in growth; none in winter | Pet-safe |
| Cosmos | Direct sun (at least 4-6 hours) | Weekly watering | Pet-safe |
| Cosmos 'Sensation' | Direct sun (at least 4-6 hours) | Water young plants until established, then only in prolonged drought; drought-tolerant once rooted | Pet-safe |
| Cosmos bipinnatus 'Picotee' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, about every 7-10 days | Pet-safe |
| Cosmos bipinnatus 'Sensation White' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, about every 7-10 days | Pet-safe |
| Cosmos sulphureus 'Bright Lights' | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, about every 7-10 days | Pet-safe |
| Cosmos sulphureus 'Klondike' | 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 |
| 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 |
| Costa Rica Pitaya | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in summer; every 2-4 weeks in winter | Pet-safe |
| 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 Orbiculata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Toxic to pets |
| 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 |
| Cramer's Amazon celosia | Direct sun (at least 4-6 hours) | Every 3–5 days | Pet-safe |
| 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 Alstonii | Direct sun (at least 4-6 hours) | Sparingly, roughly every 2-3 weeks in active growth and barely at all in dormancy | Toxic to pets |
| Crassula Capitella | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth and far less in winter | Toxic to pets |
| Crassula Columnaris | Direct sun (at least 4-6 hours) | Sparingly, roughly every 2-3 weeks in active growth and almost none during summer dormancy | Toxic to pets |
| Crassula Falcata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer, monthly or less in winter | Toxic to pets |
| Crassula Hummel's Sunset | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth and far less in winter | Toxic to pets |
| Crassula Rupestris | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 10-14 days in summer; very sparingly in winter | Toxic to pets |
| Crassula Tetragona | Direct sun (at least 4-6 hours) | When soil is dry, about every 7-12 days in summer; sparingly in winter | Toxic to pets |
| Crassula Undulata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth and far less in winter | 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 Baby's Breath | Direct sun (at least 4-6 hours) | Once per week in dry spells; very little in winter | Mildly 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 Globe Daisy | Direct sun (at least 4-6 hours) | Every 2–3 weeks when actively growing; minimal in winter | Pet-safe |
| Creeping Globularia | Direct sun (at least 4-6 hours) | Every 14 days during active growth; virtually none in winter. | Mildly toxic to pets |
| Creeping Juniper | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; weekly during the first growing season | Mildly toxic to pets |
| Creeping Little Bluestem | Direct sun (at least 4-6 hours) | Minimal once established; rainfall usually sufficient on native sites | Pet-safe |
| 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 Willow | Direct sun (at least 4-6 hours) | frequent — keep soil reliably moist | Mildly toxic to pets |
| Crested Catasetum | Direct sun (at least 4-6 hours) | Daily to every-other-day during growth; stop during dormancy | Pet-safe |
| Crested Floating Heart | Direct sun (at least 4-6 hours) | Permanently aquatic; maintain 10–60 cm water depth | Mildly toxic to pets |
| Crested Gentian | Direct sun (at least 4-6 hours) | Regular; keep soil consistently moist during the growing season | Mildly 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 |
| 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 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 |
| 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 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 | Direct sun (at least 4-6 hours) | Frequently — keep soil consistently moist to wet | 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 |
| 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 Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth; none from late autumn through winter | Pet-safe |
| Crown Imperial | Direct sun (at least 4-6 hours) | Regular in spring growth phase; dry to minimal in summer dormancy | Toxic to pets |
| Crown of Thorns | Direct sun (at least 4-6 hours) | Every 1-2 weeks in growth; sparingly in winter | Toxic to pets |
| Crown Vetch | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Crystal White narrowleaf zinnia | Direct sun (at least 4-6 hours) | Every 5–7 days; drought tolerant once established | Pet-safe |
| Cuban Lily | Direct sun (at least 4-6 hours) | Moderate in autumn through spring; restrict in summer | Toxic to pets |
| Cuban Melon Cactus | 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 3-4 weeks in winter | Pet-safe |
| 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 |
| 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 |
| Cupcake Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in summer | Pet-safe |
| Cupcakes Blush cosmos | Direct sun (at least 4-6 hours) | Every 5–7 days; drought tolerant once established | Pet-safe |
| Cuphea hyssopifolia | 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 |
| 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 Ficoides 'Mount Everest' | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 10-14 days in summer; sparingly in winter | Toxic to pets |
| Curiosity Plant | Direct sun (at least 4-6 hours) | When the mix is dry, about every 2-3 weeks in summer; minimal in winter | Pet-safe |
| Curled Air Plant | Direct sun (at least 4-6 hours) | 2–4 times weekly in summer, weekly in winter | Pet-safe |
| 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 |
| 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 |
| Cushion Baby's Breath | Direct sun (at least 4-6 hours) | Every 2–4 weeks in growing season; very sparingly or not at all in winter | Mildly toxic to pets |
| Cushion Draba | Direct sun (at least 4-6 hours) | Sparingly; soil must dry between waterings | Pet-safe |
| Cushion Sandwort | Direct sun (at least 4-6 hours) | Sparingly; allow to dry between waterings | Pet-safe |
| Cushion Thrift | Direct sun (at least 4-6 hours) | Very low — drought-tolerant once established | Mildly toxic to pets |
| Cusp Blazing Star | Direct sun (at least 4-6 hours) | Every 2-3 weeks once established; avoid irrigation in winter | Pet-safe |
| Custard Apple | Direct sun (at least 4-6 hours) | Twice weekly when establishing; weekly once mature, reducing in dry dormancy | Mildly toxic to pets |
| Custard Biriba | Direct sun (at least 4-6 hours) | 2–3 times per week in growing season; reduce in cooler months | Pet-safe |
| 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 |
| Cutleaf coneflower | Direct sun (at least 4-6 hours) | Twice weekly during establishment; weekly or more in dry spells once established | 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 |
| Cylindric Blazing Star | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; regular watering during establishment | Pet-safe |
| Cylindrical Rock Jasmine | Direct sun (at least 4-6 hours) | Very sparingly; almost none in winter | 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 papyrus | Direct sun (at least 4-6 hours) | Keep constantly wet; stand in water or water daily so the soil is never dry | Mildly toxic to pets |
| Cyprus Cedar | Direct sun (at least 4-6 hours) | Every 10-14 days when young; established trees rely mostly on rainfall | Mildly toxic to pets |
| Cyprus Cedar | Direct sun (at least 4-6 hours) | Infrequently; drought-tolerant once established | 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 |
| 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) | Deep watering 2-3 times per week, more in heat | Toxic to pets |
| Dahlia | Direct sun (at least 4-6 hours) | Twice weekly during active growth | Mildly toxic to pets |
| Dahlia 'Ace Summer Sunset' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times a week in summer once established, more during heat | Toxic to pets |
| Dahlia 'Akita' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in warm weather | Toxic to pets |
| Dahlia 'American Dawn' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week, more during heat | 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) | Deeply 2-3 times per week in active growth; keep evenly moist | 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 'Boom Boom White' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times a week through summer once established, more in heat | Toxic to pets |
| Dahlia 'Bora Bora' | Direct sun (at least 4-6 hours) | Deep watering 2-3 times weekly once established, more in heat | Mildly toxic to pets |
| Dahlia 'Breakout' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week, more in heat | 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 'Camano Ariel' | Direct sun (at least 4-6 hours) | Every 5-7 days, or when the top 2-3 cm of soil feels dry | Toxic to pets |
| Dahlia 'Contraste' | Direct sun (at least 4-6 hours) | Every 5-7 days, or when the top 2-3 cm of soil is dry | 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 'Fire Magic' | Direct sun (at least 4-6 hours) | Every 5-7 days once established, or when the top 2-3 cm of soil is dry | Toxic to pets |
| Dahlia 'Gallery Art Deco' | Direct sun (at least 4-6 hours) | Deeply 2-3 times weekly, more for containers | Mildly toxic to pets |
| Dahlia 'Ginger Snap' | Direct sun (at least 4-6 hours) | Water deeply 2-3 times a week in summer once established, more in heat | Toxic to pets |
| Dahlia 'Hollyhill Black Beauty' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week, more in heat | 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 'Karma Choc' | Direct sun (at least 4-6 hours) | Deeply 2-3 times weekly once growing strongly | Mildly toxic to pets |
| Dahlia 'Karma Naomi' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week once established, more in heat | Toxic to pets |
| Dahlia 'Labyrinth' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week, increasing in heat | 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 'Mystic Illusion' | Direct sun (at least 4-6 hours) | Deeply 2-3 times weekly when in growth | Mildly toxic to pets |
| Dahlia 'Orange Mullet' | Direct sun (at least 4-6 hours) | Every 5-7 days, or when the top 2-3 cm of soil is dry | 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 'Penhill Watermelon' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week, more during heat | 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 'Senior Ball' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days; more often in hot weather | 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 |
| Dahlia 'Thomas Edison' | Direct sun (at least 4-6 hours) | Deeply 2-3 times weekly during active growth | Mildly toxic to pets |
| Dahurian Juniper | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; more frequent in the first season | Mildly toxic to pets |
| Dahurian Larch | Direct sun (at least 4-6 hours) | Weekly during establishment; minimal once established | Pet-safe |
| Dainty Bess Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during growth | Pet-safe |
| Dalit Durian | Direct sun (at least 4-6 hours) | Daily to every other day in dry spells; less frequent during rainy seasons | Pet-safe |
| Dalmatian Cranesbill | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; minimal in winter | 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 |
| Darcey Bussell Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; container plants more often | Pet-safe |
| 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 Beauty heather | Direct sun (at least 4-6 hours) | Weekly during the first season; as needed once established | Pet-safe |
| Darley Dale heath | Direct sun (at least 4-6 hours) | Weekly while establishing; every 2–3 weeks once established | Pet-safe |
| 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 |
| 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 |
| 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 | Direct sun (at least 4-6 hours) | Weekly; keep moist in the first season | Toxic to pets |
| 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 |
| Dazzler cosmos | Direct sun (at least 4-6 hours) | Weekly until established; every 10–14 days once established | Pet-safe |
| 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 |
| Deer Grass | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; monthly or less in cool months | Pet-safe |
| 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 |
| 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 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 |
| Dense Trichodiadema | Direct sun (at least 4-6 hours) | Every 2–3 weeks during autumn and spring flowering seasons; reduced to monthly or less in summer and winter | Pet-safe |
| Dense-flowered Pachypodium | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; minimal in winter | 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 |
| Desert Bromeliad | Direct sun (at least 4-6 hours) | every 14–21 days in summer, rarely in winter | Pet-safe |
| Desert Rose | Direct sun (at least 4-6 hours) | Every 7-10 days in active growth; roughly monthly in winter dormancy | Toxic to pets |
| 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 |
| Diablo Orange Cosmos | Direct sun (at least 4-6 hours) | When the top 3–5 cm of soil is dry, roughly every 7–10 days | Pet-safe |
| 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 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 |
| 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 |
| Diapensia-Like Saxifrage | Direct sun (at least 4-6 hours) | Very low — water sparingly in spring and summer; virtually none in winter | Pet-safe |
| 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 |
| Dicliptera suberecta | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days once established | Mildly toxic to pets |
| Dinnerplate Dahlia 'Café au Lait' | Direct sun (at least 4-6 hours) | Deeply 2-3 times per week in active growth once sprouted; keep evenly moist | 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 |
| Dionaea muscipula 'Cupped Trap' | Direct sun (at least 4-6 hours) | Keep media constantly damp; sit in 1-2 cm of water in the growing season, less in dormancy | Pet-safe |
| Dionaea muscipula 'Dentate Traps' | Direct sun (at least 4-6 hours) | Keep constantly moist; tray-water with pure water | Pet-safe |
| Dionaea muscipula 'Red Dragon' | Direct sun (at least 4-6 hours) | Keep constantly moist; tray-water with pure water | Pet-safe |
| Dioon mejiae | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in growth | Toxic to pets |
| Dipladenia | Direct sun (at least 4-6 hours) | Once or twice weekly in summer; every 10–14 days in winter | Mildly toxic to pets |
| Dipladenia (Mandevilla) | Direct sun (at least 4-6 hours) | Every 3-5 days in summer growth; sparingly in winter | Mildly toxic to pets |
| 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 |
| Dog Rose | Direct sun (at least 4-6 hours) | Weekly during the first growing season; rarely once established | 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 |
| Doña Aurora | Direct sun (at least 4-6 hours) | Every 5–7 days; allow top 2–3 cm to dry slightly | Mildly toxic to pets |
| 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 |
| Dotted Blazing Star | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; moderate during first season | 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 Click Cranberries Cosmos | Direct sun (at least 4-6 hours) | When the top 3–5 cm of soil is dry, roughly every 7 days in summer | Pet-safe |
| Double Click Snow Puff cosmos | Direct sun (at least 4-6 hours) | Weekly once established; more frequent in heat | Pet-safe |
| Double Delight Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| Double Knock Out Rose | Direct sun (at least 4-6 hours) | About 2.5 cm weekly, deep watering | Pet-safe |
| Double Pink Oleander | Direct sun (at least 4-6 hours) | Water weekly when establishing; drought-tolerant once established | 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 |
| Douglas's Phlox | Direct sun (at least 4-6 hours) | Low to moderate — allow soil to partially dry between waterings | Mildly toxic to pets |
| 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 |
| Dracaena Cinnabari | Direct sun (at least 4-6 hours) | When soil is largely dry, roughly every 2-3 weeks | Toxic to pets |
| Dracaena Draco | Direct sun (at least 4-6 hours) | When the soil is mostly dry, roughly every 14-21 days | 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 Arum | Direct sun (at least 4-6 hours) | Water moderately in spring growth, letting the top few cm dry; keep dry once foliage dies down in summer | 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 |
| Dropwort | Direct sun (at least 4-6 hours) | Infrequent; drought-tolerant once established | Mildly toxic to pets |
| Drosera anglica | Direct sun (at least 4-6 hours) | Keep constantly saturated; stand in 1-3 cm of pure water through the growing season | Pet-safe |
| Drosera binata 'Multifida Extrema' | Direct sun (at least 4-6 hours) | Keep media constantly wet; stand in 1-2 cm of water via the tray method in growth, drier in winter | Mildly toxic to pets |
| Drosera burmanni | Direct sun (at least 4-6 hours) | Keep media constantly wet; stand in 1-2 cm of pure water at all times in growth | Pet-safe |
| Drosera capensis 'Red' | Direct sun (at least 4-6 hours) | Keep media constantly wet; stand in 1-2 cm of water year-round via the tray method | Mildly toxic to pets |
| Drosera Filiformis | Direct sun (at least 4-6 hours) | Keep permanently wet; stand the pot in 1-2 cm of pure water during the growing season | Mildly toxic to pets |
| Drosera intermedia | Direct sun (at least 4-6 hours) | Keep permanently saturated; stand in 1-3 cm of pure water at all times during growth | Pet-safe |
| Drummond's Pitcher Plant | Direct sun (at least 4-6 hours) | Tray method year-round (reduced in dormancy) | Pet-safe |
| Durian | Direct sun (at least 4-6 hours) | Frequent deep watering; keep soil moist with a brief drier spell to trigger flowering | Mildly toxic to pets |
| 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 |
| 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 Arolla Pine | Direct sun (at least 4-6 hours) | Low to moderate; water weekly when establishing, then drought-tolerant | Mildly toxic to pets |
| Dwarf Baby Tears | Direct sun (at least 4-6 hours) | Fully submerged — permanent aquatic plant | Pet-safe |
| Dwarf Balsam Fir | Direct sun (at least 4-6 hours) | Regularly; maintain consistently moist soil | Mildly toxic to pets |
| 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 Black Spruce | Direct sun (at least 4-6 hours) | Weekly in summer, every 2–3 weeks in winter | Mildly toxic to pets |
| Dwarf Blue Lawson Cypress | Direct sun (at least 4-6 hours) | Regular during establishment (first 2 years), then moderate | Mildly 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 Cavendish Banana | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil is dry, often every 2-4 days in active growth | Pet-safe |
| Dwarf Cedar of Lebanon | Direct sun (at least 4-6 hours) | Weekly when young; bi-weekly once established | Pet-safe |
| Dwarf Chinese Juniper | Direct sun (at least 4-6 hours) | Low to moderate — water young plants regularly; drought-tolerant once established | Mildly toxic to pets |
| Dwarf Coast Redwood | Direct sun (at least 4-6 hours) | Every 1–2 weeks; more in summer heat | Pet-safe |
| Dwarf Common Juniper | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Dwarf Creeping Juniper | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| 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 Eastern White Pine | Direct sun (at least 4-6 hours) | Regular; keep soil evenly moist, especially in the first 2–3 years | Mildly toxic to pets |
| Dwarf Edraianthus | Direct sun (at least 4-6 hours) | Low — allow to dry thoroughly between waterings | Mildly toxic to pets |
| Dwarf Golden Oriental Arborvitae | Direct sun (at least 4-6 hours) | Moderate — weekly when young, reduced once established | Toxic to pets |
| 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 Hinoki Cypress | Direct sun (at least 4-6 hours) | Regular during establishment; moderate once established | Mildly toxic to pets |
| 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 Indigo Bush | Direct sun (at least 4-6 hours) | Establish with occasional deep watering for the first season; essentially no supplemental water needed once the taproot is developed | Pet-safe |
| Dwarf Jamaican Heliconia | Direct sun (at least 4-6 hours) | Every 2–3 days in growth, weekly in winter | Mildly toxic to pets |
| Dwarf Jamaican Heliconia | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water when only the top 1-2 cm dries, roughly every 4-6 days | Pet-safe |
| Dwarf Japanese Black Pine | Direct sun (at least 4-6 hours) | Moderate when young; drought-tolerant once established | Mildly toxic to pets |
| Dwarf Japanese White Pine | Direct sun (at least 4-6 hours) | Low once established; water weekly when young | 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 Lewisia | Direct sun (at least 4-6 hours) | Moderate during spring growth; completely dry in summer | Pet-safe |
| Dwarf Oriental Spruce | Direct sun (at least 4-6 hours) | Every 7–10 days in the growing season; reduce to monthly in winter | Mildly toxic to pets |
| Dwarf Pampas Grass | Direct sun (at least 4-6 hours) | Moderate; drought-tolerant once established | Mildly toxic to pets |
| Dwarf Papyrus | Direct sun (at least 4-6 hours) | Keep roots permanently wet or in standing water 0–10 cm (0–4 in) deep | Pet-safe |
| Dwarf Pineapple | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of compost is dry, roughly every 7-10 days | Mildly toxic to pets |
| Dwarf Tongue Plant | Direct sun (at least 4-6 hours) | Every 3–4 weeks during the growing season; once a month or less in winter | Pet-safe |
| 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 White Cedar | Direct sun (at least 4-6 hours) | Regular to frequent; tolerates wet soils and does not require drought management | Mildly 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 marnier-lapostollei | Direct sun (at least 4-6 hours) | When the soil is bone dry, about every 10-14 days in summer, sparingly in winter | Pet-safe |
| 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 |
| Early Goldenrod | Direct sun (at least 4-6 hours) | Low to moderate — drought-tolerant once established | Pet-safe |
| 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 Heliconia | Direct sun (at least 4-6 hours) | 2–3 times per week in summer, weekly in winter | Mildly toxic to pets |
| Easter Lily Cactus | Direct sun (at least 4-6 hours) | When the top of the soil dries, roughly weekly to fortnightly in summer; keep almost dry in winter | 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 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 Red Cedar | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established; water young transplants for 1–2 seasons | Mildly toxic to pets |
| Eaton's Firecracker | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; minimal winter irrigation | Pet-safe |
| 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 | Direct sun (at least 4-6 hours) | When the soil is bone dry, every 10-14 days in summer | Pet-safe |
| Echeveria 'Afterglow' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria 'Blue Atoll' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria 'Chroma' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer and much less in winter | Pet-safe |
| Echeveria 'Cubic Frost' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria 'Dondo' | Direct sun (at least 4-6 hours) | When the soil is fully dry, around every 10-14 days in summer, sparingly in winter | Pet-safe |
| Echeveria 'Duchess of Nürnberg' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria 'Ice Green' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer, far less in winter | Pet-safe |
| Echeveria 'Meridian' | 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 |
| 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 'Mira' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer and rarely in winter | Pet-safe |
| Echeveria 'Neon Breakers' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria 'Orion' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer, far less in winter | Pet-safe |
| Echeveria 'Perle d'Azur' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer, much less in winter | Pet-safe |
| Echeveria 'Perle von Nurnberg' | Direct sun (at least 4-6 hours) | Every 2-3 weeks in growth; less in winter | Pet-safe |
| Echeveria 'Perle von Nürnberg' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria 'Purple Pearl' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 1-3 weeks in growth and much less in winter | Pet-safe |
| Echeveria 'Raindrops' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria 'Tarantula' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer, much less in winter | 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 'Violet Queen' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria agavoides | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria agavoides 'Ebony' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria colorata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria gibbiflora | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria harmsii | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria lilacina | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth and far less in winter | Pet-safe |
| Echeveria pallida | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer and much less in winter | Pet-safe |
| Echeveria pulidonis | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria setosa | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and every 3-4 weeks in winter | Pet-safe |
| Echeveria shaviana | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| Echeveria strictiflora | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer, sparingly in winter | Pet-safe |
| Echeveria subsessilis | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and monthly in winter | 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 |
| 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 |
| Echinocereus rigidissimus | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 12-16 days in 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 |
| Echinopsis huascha | Direct sun (at least 4-6 hours) | Soak-and-dry; roughly every 10-14 days in active growth, none in winter | Pet-safe |
| Ecuador Angel's Trumpet | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (consistent moisture essential) | Toxic to pets |
| Edelweiss | Direct sun (at least 4-6 hours) | Every 2–3 weeks; reduce to almost nothing in winter | Pet-safe |
| Eden Valley bell heather | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2–3 weeks once established | Pet-safe |
| Edith's Air Plant | Direct sun (at least 4-6 hours) | Every 2–3 days by misting | Pet-safe |
| Edithcolea grandis | Direct sun (at least 4-6 hours) | When soil is completely dry, about every 10-14 days in warm growth; keep dry below 15C | Mildly toxic to pets |
| Eglantyne Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | Pet-safe |
| Egyptian Star Flower | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry | Mildly toxic to pets |
| Egyptian White Water Lily | Direct sun (at least 4-6 hours) | Permanently submerged aquatic — maintain 22–40 cm of water over the crown | Pet-safe |
| Eichhornia crassipes | Direct sun (at least 4-6 hours) | Free-floating on warm, still or slow water; keep the pond topped up | Pet-safe |
| Elegant clarkia | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant once established | Pet-safe |
| Elegant Turk's Cap | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer; reduce to every 3-4 weeks in winter | Pet-safe |
| 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 |
| Elephant's Foot Pachypodium | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; withhold almost completely in winter | Toxic to pets |
| Elephant's Foot Pachypodium | Direct sun (at least 4-6 hours) | When the top half to two-thirds of the soil is dry in the growing season, roughly every 10-14 days in summer; almost none in winter | Toxic to pets |
| Elijah Blue Fescue | Direct sun (at least 4-6 hours) | Every 10–14 days (established); weekly when newly planted | Pet-safe |
| Elina Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season; more in heat | Pet-safe |
| 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 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 |
| Elliptic Kopsia | Direct sun (at least 4-6 hours) | Every 7–10 days when established; more frequently when young | 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 |
| 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 |
| 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 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 |
| 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 |
| Encephalartos Ferox | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in growth, far less in winter | Toxic to pets |
| Encephalartos lebomboensis | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in growth | Toxic to pets |
| Encephalartos transvenosus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly weekly to fortnightly in summer | 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 |
| Endura Scarlet Verbena | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-8 days | Toxic to pets |
| Engelmann Spruce | Direct sun (at least 4-6 hours) | Regular — keep soil consistently moist, especially in the first 3 years after planting | Pet-safe |
| 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 |
| Envy Green Zinnia | Direct sun (at least 4-6 hours) | When the top 2–4 cm of soil feels dry, roughly every 5–7 days | Pet-safe |
| Epidendrum ibaguense | Direct sun (at least 4-6 hours) | When the top of the medium feels nearly dry, roughly every 4-6 days in growth | Pet-safe |
| Epidendrum secundum | Direct sun (at least 4-6 hours) | Water about weekly, keeping the medium lightly moist; let the surface dry between waterings | Pet-safe |
| 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 |
| Ernest's Turk's Cap | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days during summer; reduce to once every 3-4 weeks in winter | Pet-safe |
| 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 |
| 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 |
| 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 aeruginosa | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in summer and monthly or less in winter | Toxic to pets |
| Euphorbia ammak | Direct sun (at least 4-6 hours) | When the top half of the soil is dry, roughly every 2-3 weeks in summer | Toxic to pets |
| Euphorbia antisyphilitica | Direct sun (at least 4-6 hours) | When fully dry, roughly every 2-3 weeks in summer, minimal in winter | Toxic to pets |
| Euphorbia caput-medusae | Direct sun (at least 4-6 hours) | When fully dry, about every 2 weeks in summer; minimal in winter | 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 columnaris | Direct sun (at least 4-6 hours) | When fully dry in warm growth, roughly every 2-3 weeks; almost none in winter | Toxic to pets |
| Euphorbia cooperi | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in summer; minimal in winter | Toxic to pets |
| Euphorbia enopla | Direct sun (at least 4-6 hours) | When fully dry, roughly every 2-3 weeks in summer; almost none in winter | Toxic to pets |
| Euphorbia esculenta | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer, near-zero in winter | Toxic to pets |
| Euphorbia ferox | Direct sun (at least 4-6 hours) | When fully dry, about every 2-3 weeks in summer; almost none in winter | Toxic to pets |
| Euphorbia globosa | Direct sun (at least 4-6 hours) | When the soil is bone dry, about every 2-3 weeks in growth, almost none in winter | Toxic to pets |
| Euphorbia gorgonis | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in growth, near-zero in winter | Toxic to pets |
| Euphorbia grandicornis | 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 |
| Euphorbia groenewaldii | Direct sun (at least 4-6 hours) | When fully dry in the growing season, about every 2-3 weeks; almost none 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 knuthii | Direct sun (at least 4-6 hours) | When fully dry in growth, about every 2-3 weeks; keep nearly dry in winter | Toxic to pets |
| Euphorbia milii 'Lutea' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 1-2 weeks; less in winter | Toxic to pets |
| Euphorbia milii 'Rosea' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is fully dry, roughly every 10-14 days in growth | Toxic to pets |
| Euphorbia obesa subsp. symmetrica | Direct sun (at least 4-6 hours) | When the soil is completely dry, roughly every 2-3 weeks in active growth; nearly dry over winter | Toxic to pets |
| Euphorbia persistentifolia | Direct sun (at least 4-6 hours) | When the soil is dry, about every 1-2 weeks in summer; sparingly in winter | Toxic to pets |
| Euphorbia piscidermis | Direct sun (at least 4-6 hours) | Sparingly, only when bone dry, roughly every 3 weeks in growth, nearly none in winter | 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 |
| Euphorbia pseudocactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer; nearly none in winter | Toxic to pets |
| Euphorbia pulvinata | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth; near-zero in winter | Toxic to pets |
| Euphorbia resinifera | Direct sun (at least 4-6 hours) | When fully dry, about every 2-3 weeks in summer; keep nearly dry in winter | Toxic to pets |
| Euphorbia schoenlandii | Direct sun (at least 4-6 hours) | When fully dry, roughly every 2-3 weeks in summer; nearly none in winter | Toxic to pets |
| Euphorbia suzannae | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2 weeks in summer, sparse in winter | Toxic to pets |
| Euphorbia symmetrica | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 2-3 weeks in growth, near-zero in winter | Toxic to pets |
| Euphorbia tirucalli 'Firesticks' | 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 |
| Euphorbia tortirama | Direct sun (at least 4-6 hours) | When the soil is fully dry during growth, roughly every 2-3 weeks; keep dry in winter dormancy | Toxic to pets |
| Euphorbia valida | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth, near-zero in winter | 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 Cypress (Goldcrest Lemon Cypress) | Direct sun (at least 4-6 hours) | When the top 2-3cm (1 inch) of mix is dry | Mildly toxic to pets |
| European Fan Palm | Direct sun (at least 4-6 hours) | Roughly weekly in spring/summer; every 2-3 weeks 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 |
| Europeana Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | Pet-safe |
| 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 |
| Evergreen Candytuft | Direct sun (at least 4-6 hours) | Every 1–2 weeks when establishing; drought-tolerant once established | Mildly toxic to pets |
| evergreen miscanthus | Direct sun (at least 4-6 hours) | Every 7–14 days during the growing season; reduce but do not cease in mild winters | Pet-safe |
| 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 |
| 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 |
| 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 Flax | Direct sun (at least 4-6 hours) | Low — rainfall is generally sufficient; water only during severe summer drought | 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 Indigo Bush | Direct sun (at least 4-6 hours) | Regular watering (every 5–7 days) during establishment; drought-tolerant once established, or tolerates periodic inundation in wet sites | Mildly toxic to pets |
| 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 |
| 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 |
| Farewell-to-spring | Direct sun (at least 4-6 hours) | Every 7–10 days; reduce once established | Pet-safe |
| 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 |
| feathertop grass | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2 weeks once established | Pet-safe |
| Feelin' Blue Deodar Cedar | Direct sun (at least 4-6 hours) | Weekly when young; monthly once established | Pet-safe |
| Feijoa | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil dries, roughly weekly in summer, less in cooler months | Mildly toxic to pets |
| 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 |
| Female Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week in growing season; reduce significantly in dry or cooler periods | Pet-safe |
| Fenestraria Aurantiaca | Direct sun (at least 4-6 hours) | Sparingly, roughly every 2-3 weeks during autumn-to-spring growth and withheld through summer dormancy | Mildly toxic to pets |
| Fenestraria Rhopalophylla | Direct sun (at least 4-6 hours) | Only when the leaves start to wrinkle, roughly every 2-3 weeks in active growth and almost never in summer dormancy | Mildly toxic to pets |
| 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 |
| Fernleaf yarrow | Direct sun (at least 4-6 hours) | Water when top 5 cm of soil is dry; drought-tolerant once established | Mildly toxic to pets |
| Ferocactus glaucescens | Direct sun (at least 4-6 hours) | Soak-and-dry, roughly every 14 days in summer; keep dry in winter | Pet-safe |
| Ferocactus latispinus | Direct sun (at least 4-6 hours) | Soak-and-dry, roughly every 14 days in summer; keep dry in winter | Pet-safe |
| Ferocactus schwarzii | Direct sun (at least 4-6 hours) | Soak-and-dry, roughly every 10-14 days in summer; keep dry 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 |
| Field Bindweed | Direct sun (at least 4-6 hours) | Low — extremely drought-tolerant once established | Toxic to pets |
| Field Chickweed | Direct sun (at least 4-6 hours) | Every 7–14 days in the growing season; very sparingly in autumn and winter | Pet-safe |
| 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 Mouse-ear | Direct sun (at least 4-6 hours) | Very low — drought tolerant once established | Mildly toxic to pets |
| 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 |
| Field Wood Rush | Direct sun (at least 4-6 hours) | No supplemental watering needed in typical temperate climates; relies on natural rainfall | Pet-safe |
| 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 Cactus | Direct sun (at least 4-6 hours) | When the soil has dried fully, roughly every 2-3 weeks in summer; keep dry in 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 |
| 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 |
| Fire Barrel Cactus | Direct sun (at least 4-6 hours) | Every 2-4 weeks in summer; withhold in winter | Mildly toxic to pets |
| Fire Crown Cactus | Direct sun (at least 4-6 hours) | When the mix is completely dry, about every 10-14 days in growth; withhold entirely in winter | Pet-safe |
| Fire Star Orchid | Direct sun (at least 4-6 hours) | When the top 2-3 cm of the mix is dry, roughly every 5-7 days | Pet-safe |
| 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 |
| Firefly heather | Direct sun (at least 4-6 hours) | Weekly during establishment; occasional deep watering once established | Pet-safe |
| Firesticks Plant | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in growth | 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 |
| Fireworks Globe Amaranth | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| 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 completely dry, roughly every 2-3 weeks in summer; little to none from late autumn through 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 |
| Five-angled Pipewort | Direct sun (at least 4-6 hours) | Fully submerged; 30-40% water change weekly | Mildly toxic to pets |
| Flaky Juniper | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; weekly during establishment year | Mildly toxic to pets |
| Flame Freesia | Direct sun (at least 4-6 hours) | Water freely in active growth; withhold completely during summer dormancy | Mildly toxic to pets |
| 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 Feather Celosia | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 6-8 days | Pet-safe |
| Flanagan's Sage | Direct sun (at least 4-6 hours) | Every 10-14 days during the growing season; rarely in winter | Pet-safe |
| Flat Sea Holly | Direct sun (at least 4-6 hours) | Low — water occasionally during the first growing season, then minimal | Pet-safe |
| 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 |
| Flat-Leaved Rosularia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season; minimal in winter | Pet-safe |
| Flax-leaved Tulip | Direct sun (at least 4-6 hours) | Water during active growth; keep dry in summer | 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 Silver Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days, less in winter | Mildly 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 |
| 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 Banana | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 5-7 days in growing season | 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 maple | Direct sun (at least 4-6 hours) | When the top 1 cm (½ inch) of mix is dry, often every few days in summer | Mildly toxic to pets |
| 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 |
| Flying Saucer Cactus | Direct sun (at least 4-6 hours) | When the top of the soil is dry, roughly weekly to fortnightly in summer; keep nearly dry in winter | Pet-safe |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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 Pogostemon | Direct sun (at least 4-6 hours) | Fully submerged; maintain stable water column — partial water changes of 20-30% weekly | Mildly toxic to pets |
| 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 beardtongue | Direct sun (at least 4-6 hours) | Every 7–10 days during establishment; drought-tolerant once established | 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 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 Orchid | Direct sun (at least 4-6 hours) | Very low to low — rain-fed only | Mildly toxic to pets |
| Fragrant Water Lily | Direct sun (at least 4-6 hours) | Aquatic — permanently grown in standing water | Toxic to pets |
| Fragrant White Water Lily | Direct sun (at least 4-6 hours) | Permanently submerged aquatic — maintain water depth of 30–60 cm over the crown | Pet-safe |
| 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 |
| 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 marigold | Direct sun (at least 4-6 hours) | Once or twice weekly; let the top 2 cm of soil dry between waterings | Mildly toxic to pets |
| French Marigold 'Durango' | Direct sun (at least 4-6 hours) | When top 2-3 cm of soil is dry, every 3-6 days; containers more often | Mildly toxic to pets |
| French Tamarisk | Direct sun (at least 4-6 hours) | Moderate; drought-tolerant once established | Pet-safe |
| Fresh Look Red Cockscomb | Direct sun (at least 4-6 hours) | When the top 2–3 cm of soil is dry, roughly every 5–7 days | 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 |
| Fringed Caralluma | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; very sparingly in winter | 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 Coreopsis | Direct sun (at least 4-6 hours) | Every 1–2 weeks once established; more frequently when young | Pet-safe |
| Fringed Houseleek | Direct sun (at least 4-6 hours) | Low — water sparingly, allowing soil to dry fully | Pet-safe |
| Frithia humilis | Direct sun (at least 4-6 hours) | When soil is fully dry during spring-summer growth; minimal in winter | Pet-safe |
| Frithia pulchra | Direct sun (at least 4-6 hours) | When soil is fully dry during spring-summer growth; sparing in winter | Pet-safe |
| 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 |
| Front Range Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; minimal in winter | Pet-safe |
| Fruit-scented Sage | Direct sun (at least 4-6 hours) | When the top 3-5 cm of compost is dry — roughly every 5-8 days in summer, less often in winter | Pet-safe |
| Fuerte Avocado | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, about every 5-7 days in warm growth | Toxic to pets |
| 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 'Arizona Sun' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 7-10 days once established | Mildly toxic to pets |
| 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 'Goblin' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days once established | 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 |
| Gamboge | Direct sun (at least 4-6 hours) | Twice weekly; more frequently in hot weather | Mildly toxic to pets |
| Garden Catmint | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly every 7-10 days while establishing, then rarely | Mildly toxic to pets |
| Garden Gladiolus | Direct sun (at least 4-6 hours) | Weekly deep watering during active growth; reduce after flowering; cease after first frost kills foliage | 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 |
| Garlic Bignone | Direct sun (at least 4-6 hours) | Every 7–10 days; drought-tolerant when established | Mildly toxic to pets |
| 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 |
| Gazania × hybrida 'Tiger Stripes' | 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 |
| Gazania rigens 'Daybreak Garden Sun' | 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 |
| Geay's Pachypodium | Direct sun (at least 4-6 hours) | When the top half of the soil is dry during the growing season, roughly every 7-14 days in summer; minimal to none in winter | 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 (pelargonium) | Direct sun (at least 4-6 hours) | When the top of the soil is dry, every 5-10 days | 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 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 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 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 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 |
| 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 'Mrs. J. Bradshaw' | Direct sun (at least 4-6 hours) | Water when the top 3 cm of soil dries, about weekly | 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 Plant | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in summer and monthly or less in winter | Pet-safe |
| Giant Arrowhead | Direct sun (at least 4-6 hours) | Permanently aquatic — plant in still or slow-moving water 10–15 cm (4–6 in) deep; tolerates up to 30 cm (12 in). | 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 Bamboo | Direct sun (at least 4-6 hours) | Frequently; requires abundant moisture year-round | Pet-safe |
| 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 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 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 Dorstenia | Direct sun (at least 4-6 hours) | Every 7–14 days in summer; every 3–4 weeks in winter | Mildly toxic to pets |
| 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 Ginger Lily | Direct sun (at least 4-6 hours) | Generously during active growth; reduce markedly in autumn and 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 Ixora | Direct sun (at least 4-6 hours) | Every 2-3 days in warm weather, once a week in cooler periods | 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 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 reed grass | Direct sun (at least 4-6 hours) | Regularly; prefers medium to wet conditions and will grow in standing water | Mildly toxic to pets |
| Giant Sacaton | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; more frequent during establishment | Pet-safe |
| Giant Sacaton Grass | Direct sun (at least 4-6 hours) | Water to establish the first season, then occasionally in drought, roughly every 2-3 weeks | Mildly toxic to pets |
| Giant Sea Holly | Direct sun (at least 4-6 hours) | Moderate — water regularly to keep soil evenly moist, especially 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 Sunburst Lotus | Direct sun (at least 4-6 hours) | Aquatic — continuously in still or gently moving water | Mildly toxic to pets |
| 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 Thorny Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week during the growing season; reduce in the dry season | Pet-safe |
| 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 Water Lily | Direct sun (at least 4-6 hours) | Permanently submerged — maintain 40–80 cm of water over the crown | 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 |
| Girard's Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; very sparingly in winter | 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 |
| Gladiolus 'Traderhorn' | Direct sun (at least 4-6 hours) | Roughly weekly, 25mm (1 inch) per week during active growth and budding | Toxic to pets |
| Gladiolus callianthus | Direct sun (at least 4-6 hours) | Weekly during growth, keeping soil moist but never sodden | 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 |
| 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 |
| 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 |
| Glenn Mango | Direct sun (at least 4-6 hours) | Deep soak when the top few centimetres of soil dry, about every 5-10 days in growth | Pet-safe |
| Globe amaranth | Direct sun (at least 4-6 hours) | Every 7–10 days; drought-tolerant once established | Pet-safe |
| Globe Blue Spruce | Direct sun (at least 4-6 hours) | Weekly during the first 2 years; every 2–3 weeks once established | Mildly toxic to pets |
| 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 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 |
| Gmelin's Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established | Pet-safe |
| 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 fully dry, roughly every 2-3 weeks in summer; keep dry from late autumn through winter | 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 Dust Alyssum | Direct sun (at least 4-6 hours) | Fortnightly to monthly once established (very drought-tolerant) | Pet-safe |
| Gold Haze heather | Direct sun (at least 4-6 hours) | Weekly during first season; occasional watering once established | Pet-safe |
| 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) | Regularly — keep soil consistently moist, especially in summer | Pet-safe |
| 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 Apple | Direct sun (at least 4-6 hours) | Every 7–14 days; moderate drought tolerance when established | Pet-safe |
| Golden Ash | Direct sun (at least 4-6 hours) | Moderate; regular deep watering when establishing | Pet-safe |
| Golden Ball Cactus | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 7-10 days in summer; minimal in winter | 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) | Every 2-3 weeks in spring/summer; every 4-6 weeks in winter | Mildly toxic to pets |
| 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 Chalice Vine | Direct sun (at least 4-6 hours) | Weekly in active growth; every 2–3 weeks in winter | Toxic to pets |
| 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 Glow bougainvillea | Direct sun (at least 4-6 hours) | Every 7–14 days during growth; reduce for 3–4 week dry cycles to trigger bract flush | 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 Lace Cactus | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 2-3 weeks in summer; keep nearly dry in winter | Pet-safe |
| Golden Malayan Dwarf Coconut | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 3-5 days in heat, never drying out fully | Pet-safe |
| Golden Powder Puff | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in active growth; none in winter | Pet-safe |
| Golden Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–4 weeks when established; very little 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 St. John's Wort | Direct sun (at least 4-6 hours) | Weekly during the first growing season; minimal once established | Mildly toxic to pets |
| 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 Torch Cactus | Direct sun (at least 4-6 hours) | When the soil is dry, about weekly to fortnightly in summer; keep dry in winter | Pet-safe |
| Golden Trumpet | Direct sun (at least 4-6 hours) | When the top 2-5 cm of soil is dry (roughly weekly in summer) | 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-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 |
| Goldenrod | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| Goldfinger Banana | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil is dry, every 2-4 days in active growth | Pet-safe |
| Goldmoss Stonecrop | Direct sun (at least 4-6 hours) | Rarely — established plants rely on rainfall; water only in prolonged drought | Mildly toxic to pets |
| Gomphrena globosa 'QIS Pink' | Direct sun (at least 4-6 hours) | Water deeply once a week; let soil dry between waterings | Pet-safe |
| Gomphrena haageana 'Strawberry Fields' | Direct sun (at least 4-6 hours) | Water deeply about weekly; allow soil to dry between | Mildly 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 |
| Gracillimus Maiden Grass | Direct sun (at least 4-6 hours) | Weekly in year one, then mainly during extended dry spells | Mildly toxic to pets |
| Graham Thomas Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| Grand Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; rainfall-dependent once mature | Pet-safe |
| Grandidier's Baobab | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; virtually none in autumn–winter dormancy | Pet-safe |
| Grandidier's Uncarina | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; withhold almost entirely October–March | Mildly toxic to pets |
| Grapeleaf Abutilon | Direct sun (at least 4-6 hours) | Moderate; established plants are fairly drought-tolerant | Mildly toxic to pets |
| Graptopetalum amethystinum | Direct sun (at least 4-6 hours) | When the soil is completely dry, about every 12-16 days in summer, sparingly in winter | Pet-safe |
| Graptopetalum macdougallii | Direct sun (at least 4-6 hours) | When the soil is completely dry, about every 12-16 days in summer, minimal in winter | Pet-safe |
| Graptopetalum pentandrum | Direct sun (at least 4-6 hours) | Every 2-3 weeks (less in winter) | Pet-safe |
| 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 |
| Graptosedum 'Francesco Baldi' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer, sparingly in winter | Pet-safe |
| Graptosedum 'Vera Higgins' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer, sparingly 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 'Bashful' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth, sparingly in winter | Mildly toxic to pets |
| Graptoveria 'Debbie' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth, minimal in winter | Mildly toxic to pets |
| Graptoveria 'Fred Ives' | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly 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 |
| Graptoveria 'Opalina' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth, sparingly in winter | Mildly toxic to pets |
| Graptoveria 'Silver Star' | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth, minimal in winter | Mildly toxic to pets |
| Graptoveria 'Titubans' | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in growth, far less in winter | Pet-safe |
| grass-leaved bladderwort | Direct sun (at least 4-6 hours) | Permanently submerged in shallow aquarium or terrarium water column | Pet-safe |
| Grass-Leaved Edraianthus | Direct sun (at least 4-6 hours) | Low — allow soil to partially dry between waterings | Mildly toxic to pets |
| Grass-Leaved Ginger | Direct sun (at least 4-6 hours) | 2–3 times per week during active growth; reduce to once a week or less in winter | Mildly toxic to pets |
| Grass-leaved Zamia | Direct sun (at least 4-6 hours) | Every 14–21 days in growing season; monthly or less in winter | Toxic to pets |
| 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 |
| 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 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 |
| Greater Duckweed | Direct sun (at least 4-6 hours) | Permanently floating on water surface | 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 |
| Greek Fir | Direct sun (at least 4-6 hours) | Every 2–3 weeks during establishment; rarely needed once mature | 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 Glaucous Bamboo | Direct sun (at least 4-6 hours) | Twice weekly during establishment; every 7–14 days once mature | Pet-safe |
| 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 Sapote | Direct sun (at least 4-6 hours) | Every 7–10 days; allow partial drying between irrigations | Mildly 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-winged Orchid | Direct sun (at least 4-6 hours) | Rain-fed; moist spring, dry summer dormancy | Mildly toxic to pets |
| 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 Goldenrod | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Pet-safe |
| Grey Moor Grass | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | 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 |
| Grey-Headed Coneflower | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; drought-tolerant | 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 |
| Grumichama | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil dries, roughly weekly; keep young plants evenly moist | Mildly toxic to pets |
| Guadua Bamboo | Direct sun (at least 4-6 hours) | Frequently during establishment; moderate once mature | Pet-safe |
| Guapeva | Direct sun (at least 4-6 hours) | Every 5–7 days when young; established trees tolerate short dry spells | Mildly toxic to pets |
| Guariroba Palm | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 7-10 days in summer | Pet-safe |
| Guava | Direct sun (at least 4-6 hours) | Deeply every 5-10 days; keep evenly moist during flowering and fruiting, then allow brief dry spells | 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 |
| Gulf Muhly | Direct sun (at least 4-6 hours) | Water through the first season to establish, then only in drought, roughly every 2 weeks | Mildly 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 |
| Gummy Uebelmannia | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, approximately every 10-14 days in summer; barely once a month in winter | Pet-safe |
| Gurken's Orthophytum | Direct sun (at least 4-6 hours) | Allow to dry between waterings — roughly every 7–10 days | Pet-safe |
| H.E. Beale heather | Direct sun (at least 4-6 hours) | Weekly during first season; monthly or as needed once established | Pet-safe |
| 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 Coreopsis | Direct sun (at least 4-6 hours) | Low to moderate; water during establishment, then as needed during drought | Pet-safe |
| Hairy Houseleek | Direct sun (at least 4-6 hours) | Every 2–4 weeks in the growing season; once a month or less in winter | Pet-safe |
| Hairy Jovibarba | Direct sun (at least 4-6 hours) | Every 2–4 weeks during the growing season; sparingly in winter | Pet-safe |
| Hairy Mallow | Direct sun (at least 4-6 hours) | Every 7–10 days in summer, every 14–21 days in winter | Pet-safe |
| Hairy Rattleweed | Direct sun (at least 4-6 hours) | Low; allow soil to dry between waterings | Toxic to pets |
| Hairy Rock Jasmine | Direct sun (at least 4-6 hours) | Sparingly; dry conditions preferred especially in winter | Pet-safe |
| 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 Stonecrop | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season; minimal in winter | 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 Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established | 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 |
| 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'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 |
| Hanging Lobster Claw | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water when only the top 1-2 cm dries, roughly every 3-5 days in warm conditions | Pet-safe |
| Hansa Rose | Direct sun (at least 4-6 hours) | Water weekly while establishing; drought-tolerant once settled | 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 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 |
| Harebell | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | 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 |
| Hass Avocado | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, roughly every 5-7 days in warm growth | Toxic to pets |
| 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 |
| 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 |
| Hawaii Blue Flossflower | Direct sun (at least 4-6 hours) | When the top 2 cm of soil is dry, roughly every 5-7 days | Toxic to pets |
| 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 |
| 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 of Fire | Direct sun (at least 4-6 hours) | Every 7–14 days; less in winter | Mildly toxic to pets |
| Heart of Fire Bromeliad | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in summer | Mildly toxic to pets |
| Heart of Flame Bromeliad | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 2–3 weeks in winter | Mildly toxic to pets |
| Heart-leaved Globe Daisy | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; very sparingly in winter | Pet-safe |
| Heath-leaved Sage | Direct sun (at least 4-6 hours) | Low; water deeply every 2–3 weeks when established | Mildly toxic to pets |
| Heather | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once established | Pet-safe |
| Heavenly blue morning glory | Direct sun (at least 4-6 hours) | Once or twice a week in dry periods; reduce once established | 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 |
| Heavy Metal Switchgrass | Direct sun (at least 4-6 hours) | Weekly when establishing; every 2–3 weeks once established | Pet-safe |
| 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 |
| 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 |
| Hedgehog Fescue | Direct sun (at least 4-6 hours) | Every 14–21 days when established; very sparingly in winter | 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 'Moerheim Beauty' | Direct sun (at least 4-6 hours) | Keep evenly moist; water every 4-7 days, more often in dry heat | 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 consistently moist; water every 4-7 days, more in heat | 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 |
| 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 |
| 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 |
| Hemianthus callitrichoides 'Cuba' | Direct sun (at least 4-6 hours) | Permanently submerged; 30-50% water change weekly | 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 |
| Henderson's Allamanda | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; sparingly in winter | Toxic to pets |
| Hens and chicks | Direct sun (at least 4-6 hours) | Only when soil is fully dry; roughly every 1-2 weeks in summer, every 4-6 weeks in winter | Pet-safe |
| 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 |
| 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 |
| 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 |
| Heuffel's Houseleek | Direct sun (at least 4-6 hours) | Low — allow to dry between waterings | Mildly toxic to pets |
| Heuffel's Jovibarba | Direct sun (at least 4-6 hours) | Every 2–4 weeks in growing season; rarely in winter | Pet-safe |
| Hibiscus | Direct sun (at least 4-6 hours) | Deep watering every 5-7 days, more in heat | Pet-safe |
| Hibiscus rosa-sinensis 'Cooper' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, every 3-5 days in active growth | 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 |
| Hikuri | Direct sun (at least 4-6 hours) | Sparingly: only when soil is fully dry, roughly every 2-3 weeks in summer, none in winter | 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 |
| 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 |
| 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 |
| Holger Juniper | Direct sun (at least 4-6 hours) | Water regularly the first season; afterward only in extended drought | Toxic to pets |
| Holger's Juniper | Direct sun (at least 4-6 hours) | Low — water deeply but infrequently once established | Mildly 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 |
| Hollyhock | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce in autumn and winter | Pet-safe |
| 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 |
| 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-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 |
| Hoodia gordonii | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in summer; keep nearly dry October-March | Mildly toxic to pets |
| Hoodia parviflora | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 10-14 days in summer; keep nearly dry in winter | Mildly 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 |
| Hoop Petticoat Daffodil | Direct sun (at least 4-6 hours) | Regular during active growth; dry in summer dormancy | Toxic to pets |
| 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 Tulip | Direct sun (at least 4-6 hours) | Moderate during active growth; dry in summer | Toxic to pets |
| Horombe Pachypodium | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; none from late autumn to mid-spring | Toxic to pets |
| 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 Discocactus | 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; reduce to once a month or less in winter | Pet-safe |
| 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 |
| Houttuynia cordata | Direct sun (at least 4-6 hours) | Keep soil constantly wet to waterlogged; never let it dry out | Mildly toxic to pets |
| Houttuynia cordata 'Chameleon' | Direct sun (at least 4-6 hours) | Keep soil constantly wet to waterlogged; never allow it to dry | Mildly toxic to pets |
| 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 |
| Humped Bladderwort | Direct sun (at least 4-6 hours) | Keep permanently submerged; top up to maintain a constant water level | 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 |
| 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 |
| 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 '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 '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 '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 '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 '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 |
| 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 |
| Ice Cream Banana | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil dries, every 2-4 days in warm growth | Pet-safe |
| Ice Cream Bean | Direct sun (at least 4-6 hours) | Deeply once or twice a week; reduce in cooler months | Mildly toxic to pets |
| Ice Follies Daffodil | Direct sun (at least 4-6 hours) | Moderate during autumn–spring; dry in summer dormancy | 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 |
| Iceberg Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | 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 |
| Ilama | Direct sun (at least 4-6 hours) | Deeply every 7-10 days in the growing season; reduce sharply in the dry/cool dormant period | Mildly toxic to pets |
| Illinois Tick Trefoil | Direct sun (at least 4-6 hours) | Deep watering every 10–14 days during the first growing season; drought-tolerant once established | Pet-safe |
| Impala Lily | Direct sun (at least 4-6 hours) | Every 7–10 days in warm growing season; withhold almost entirely during dormancy (autumn–late winter) | Toxic to pets |
| Impatiens hawkeri 'SunPatiens Compact Hot Coral' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, often daily in full sun during summer | Pet-safe |
| Impatiens hawkeri 'SunPatiens Spreading White' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, often daily in full sun and in baskets | Pet-safe |
| Imperial Bromeliad | Direct sun (at least 4-6 hours) | Water sparingly; allow potting medium to almost completely dry between waterings | Pet-safe |
| Incense Cedar | Direct sun (at least 4-6 hours) | Every 7–10 days when young; established trees are drought-tolerant and rely mainly on rainfall | Mildly toxic to pets |
| Indian Blanket | Direct sun (at least 4-6 hours) | Every 1–2 weeks; drought-tolerant once established | Pet-safe |
| 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 Gooseberry | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-10 days in growth | Mildly toxic to pets |
| indian grass | Direct sun (at least 4-6 hours) | Rarely once established; water during the first growing season to aid establishment | 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 Shot | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-7 days | 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 |
| Indian Summer black-eyed Susan | Direct sun (at least 4-6 hours) | Weekly; allow the top 2–3 cm of soil to dry slightly between waterings | Pet-safe |
| Indian Summer Black-Eyed Susan | 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 |
| Indian Timber Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week during the growing season; reduce in winter | Pet-safe |
| 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 |
| 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 |
| Interrupted Sage | Direct sun (at least 4-6 hours) | Every 7–14 days in summer; very sparingly in winter | Mildly toxic to pets |
| Intrigue Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times weekly, about 4-5 litres per plant | Pet-safe |
| Ipomoea batatas 'Blackie' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, often every 2-3 days in containers in summer | Toxic to pets |
| Ipomoea lobata | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-6 days in summer | Toxic to pets |
| Ipomoea nil 'Scarlett O'Hara' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 3-5 days in summer | Toxic to pets |
| Ipomoea purpurea | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 3-5 days in summer heat | Toxic to pets |
| Ipomoea quamoclit | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 4-6 days in summer | Toxic to pets |
| Ipomoea tricolor 'Heavenly Blue' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days in warm weather | 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 | Direct sun (at least 4-6 hours) | Weekly watering during growth | Toxic to pets |
| 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 |
| Irish heath | Direct sun (at least 4-6 hours) | Weekly while establishing; every 2–3 weeks once established | Pet-safe |
| Irish Heath Irish Dusk | Direct sun (at least 4-6 hours) | Regular during establishment; moderate once settled | Mildly toxic to pets |
| 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 Sage Phlomis | Direct sun (at least 4-6 hours) | Low — once every 2–3 weeks once established | 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 |
| Ivory Sea Holly | Direct sun (at least 4-6 hours) | Moderate — water regularly during the growing season; reduce in winter | Pet-safe |
| Ivyleaf morning glory | Direct sun (at least 4-6 hours) | Once or twice a week; allow soil to dry slightly between waterings | Toxic to pets |
| Jaboticaba | Direct sun (at least 4-6 hours) | Keep consistently moist; water when the top 3-4 cm of soil dries, often 1-2 times weekly | Mildly toxic to pets |
| Jacaranda Tree Succulent | Direct sun (at least 4-6 hours) | Every 7–10 days in summer (when leafed out); once a month or not at all in winter dormancy | Mildly toxic to pets |
| Jackfruit | Direct sun (at least 4-6 hours) | Deeply every 5-10 days; keep young trees evenly moist, with a drier spell tolerated by established trees | Mildly toxic to pets |
| Jade plant | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 2-3 weeks | Toxic to pets |
| Jagged Lavender | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; every 3–4 weeks in winter | Toxic to pets |
| Jamaican Tall Coconut | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 3-5 days in heat, never drying out fully | Pet-safe |
| 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 Arborvitae | Direct sun (at least 4-6 hours) | Regular — keep soil evenly moist; do not allow to dry out completely | Pet-safe |
| 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 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 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 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 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 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 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 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 Mazus | Direct sun (at least 4-6 hours) | Every 3–5 days; prefers moist, consistently watered soil | Mildly toxic to pets |
| Japanese morning glory | Direct sun (at least 4-6 hours) | 2–3 times per week in containers; once a week in garden beds during dry spells | 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 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 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 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 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 |
| Jasminum sambac 'Grand Duke of Tuscany' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days in growth | Pet-safe |
| Jasminum sambac 'Maid of Orleans' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-6 days in warm growth | Pet-safe |
| Java Plum | Direct sun (at least 4-6 hours) | Water regularly when young; established trees are drought-tolerant and flood-tolerant. | 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 |
| 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 coat | 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 |
| Joseph's Coat Amaranth | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| 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 |
| Jujube | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, every 1-2 weeks once established | Mildly toxic to pets |
| Julia Child Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| Jungle Geranium | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm of soil feels dry, roughly 1-2 times per week in growth | 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 |
| Just Joey Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while in growth | Pet-safe |
| Kalanchoe | Direct sun (at least 4-6 hours) | When the soil is dry, every 10-14 days | Toxic to pets |
| Kalanchoe Beharensis | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 2-3 weeks in summer, monthly in winter | Toxic to pets |
| Kalanchoe Orgyalis | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 2-3 weeks in summer, monthly in winter | Toxic to pets |
| Kalanchoe Thyrsiflora | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 2-3 weeks in summer, monthly or less in winter | 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 |
| 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 |
| Karatas Bromeliad | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days in growing season | Mildly toxic to pets |
| 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 |
| 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 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 |
| Keitt Mango | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries during growth; reduce before flowering | Mildly toxic to pets |
| Kelsey's Phlox | Direct sun (at least 4-6 hours) | Low to moderate — allow soil to dry between waterings | Mildly toxic to pets |
| Kent Mango | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries in growth; reduce in the cool/dry rest period | Mildly 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 |
| Khimp | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; once a month or less in winter | 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 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 |
| King Alfred Daffodil | Direct sun (at least 4-6 hours) | Moderate during growing season; dry during summer dormancy | 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 Size Scarlet everlasting | Direct sun (at least 4-6 hours) | Every 7–10 days; water deeply then let soil partially dry | Pet-safe |
| King Sundew | Direct sun (at least 4-6 hours) | Keep the pot standing in 1-2 cm of water at all times; top up before the tray runs dry | Mildly toxic to pets |
| Kiwano | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm dries, often every 2-4 days in heat | 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 |
| Kokum | Direct sun (at least 4-6 hours) | Water regularly to keep soil consistently moist; do not allow to dry out. | 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 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 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 |
| Korlan | Direct sun (at least 4-6 hours) | Every 4–6 days for young trees; reduce to every 10–14 days once established in seasonally wet climates | Mildly toxic to pets |
| 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-bark Pine | Direct sun (at least 4-6 hours) | Water young trees weekly in dry spells; established trees rarely | Mildly 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 |
| Lady Finger Banana | Direct sun (at least 4-6 hours) | Keep consistently moist; water when the top 2-3 cm of soil dries, roughly every 2-4 days in warm growth | Pet-safe |
| Lady Finger Cactus | Direct sun (at least 4-6 hours) | Roughly every 2-3 weeks in summer; far less in winter | Pet-safe |
| 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 Tulip | Direct sun (at least 4-6 hours) | Moderate in spring; dry in summer | Toxic to pets |
| Ladybird Scarlet cosmos | Direct sun (at least 4-6 hours) | Weekly; allow soil surface to dry between waterings | Pet-safe |
| Lamb Hass Avocado | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, roughly every 5-7 days in warm growth | 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 |
| 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 |
| Lanceleaf Coreopsis | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; weekly to establish, then rarely | 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 |
| Larch-leaved Sandwort | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; minimal in winter | Pet-safe |
| Larch-Leaved Stitchwort | Direct sun (at least 4-6 hours) | Very low — drought-tolerant; water sparingly | 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-flowered Bacopa | Direct sun (at least 4-6 hours) | Keep soil evenly and consistently moist | Mildly toxic to pets |
| Large-Flowered Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; moderate during first growing season | Mildly toxic to pets |
| 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 Houseleek | Direct sun (at least 4-6 hours) | Low — drought-tolerant; water only in prolonged dry periods | 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 Clockvine | Direct sun (at least 4-6 hours) | Every 2–4 days during active growth; reduce in cooler months | Mildly toxic to pets |
| 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 |
| Lavaglut Rose | Direct sun (at least 4-6 hours) | Deeply once or twice a week, more in heat | Pet-safe |
| Lavender | Direct sun (at least 4-6 hours) | When the top of the soil is dry, every 10-14 days | 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 |
| Laza Cyphostemma | Direct sun (at least 4-6 hours) | Every 3–5 days in peak summer growing season; almost none in winter | Mildly toxic to pets |
| Lead Plant | Direct sun (at least 4-6 hours) | Deeply once every 2–3 weeks during the first growing season; essentially no supplemental irrigation once established | 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 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 |
| 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 |
| 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 |
| Lehmann's Iceplant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during spring and summer; monthly or less in winter | 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 |
| Lemon Drop Mangosteen | Direct sun (at least 4-6 hours) | Water regularly; requires consistently moist soil and high annual rainfall equivalent. | Mildly toxic to pets |
| 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 Silver Saxifrage | Direct sun (at least 4-6 hours) | Low — water only when the top layer of grit is dry | Pet-safe |
| Lesser Spearwort | Direct sun (at least 4-6 hours) | Saturated mud to 5 cm standing water | 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 |
| 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 |
| Licuri Palm | Direct sun (at least 4-6 hours) | When the top 5 cm of soil is dry, roughly every 10-14 days or less | 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 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 |
| Lilium 'Black Beauty' | Direct sun (at least 4-6 hours) | When the top 3-5cm of soil is dry, roughly weekly in the growing season | Toxic to pets |
| Lilium 'Casa Blanca' | Direct sun (at least 4-6 hours) | When the top 3-5cm of soil is dry, about weekly during active growth | Toxic to pets |
| Lilium 'Conca d'Or' | Direct sun (at least 4-6 hours) | When the top 3-5cm of soil is dry, about weekly during growth | Toxic to pets |
| Lilium 'Dizzy' | Direct sun (at least 4-6 hours) | Keep evenly moist in growth, about weekly; never waterlogged | Toxic to pets |
| Lilium 'Matrix' | Direct sun (at least 4-6 hours) | Keep evenly moist through growth and bloom, about weekly; avoid waterlogging | Toxic to pets |
| Lilium 'Regale' | Direct sun (at least 4-6 hours) | When the top 3-5cm of soil is dry, roughly weekly during active growth | Toxic to pets |
| Lilium 'Stargazer' | Direct sun (at least 4-6 hours) | When the top 3-5cm of soil is dry, roughly weekly during growth and flowering | Toxic to pets |
| Lilium 'Tiny Bee' | Direct sun (at least 4-6 hours) | When the top 2-3cm of soil is dry, roughly weekly; more often in pots | Toxic to pets |
| Lilium lancifolium | Direct sun (at least 4-6 hours) | Keep evenly moist in active growth, roughly weekly; never waterlogged | Toxic to pets |
| Limestone Saxifrage | Direct sun (at least 4-6 hours) | Low — water sparingly, allow soil to approach dryness between waterings | Pet-safe |
| 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 |
| Lindheimer's Muhly | Direct sun (at least 4-6 hours) | Water to establish the first season, then occasionally in drought, roughly every 2-3 weeks | Mildly toxic to pets |
| Lipstick Echeveria | Direct sun (at least 4-6 hours) | Every 1-2 weeks in spring/summer; sparingly in winter | Pet-safe |
| 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 | Direct sun (at least 4-6 hours) | Follow the seasonal cycle, not a schedule | Pet-safe |
| Lithops Aucampiae | Direct sun (at least 4-6 hours) | Strictly seasonal: water in spring and autumn only, never in summer dormancy or mid-winter | Pet-safe |
| Lithops Bromfieldii | Direct sun (at least 4-6 hours) | Seasonally, only every few weeks during active growth and not at all during leaf renewal | Pet-safe |
| Lithops Divergens | Direct sun (at least 4-6 hours) | Only in autumn and spring growth, sparingly when soil is bone dry; no water during summer or mid-winter rest | Pet-safe |
| Lithops Hookeri | Direct sun (at least 4-6 hours) | Strictly seasonal: water in spring and autumn only, never during summer dormancy or mid-winter | Pet-safe |
| Lithops Lesliei | Direct sun (at least 4-6 hours) | Strictly seasonal: water in spring and autumn only, never during summer dormancy or mid-winter | 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 Bluestem | Direct sun (at least 4-6 hours) | Every 2–3 weeks during establishment; minimal once established | 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 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 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 silver spider grass | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; reduce significantly in winter | Pet-safe |
| 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 |
| Living Stones | Direct sun (at least 4-6 hours) | Very infrequently and strictly by season, often only every few weeks and not at all in summer or deep 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 |
| 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 erinus 'Techno Heat Blue' | Direct sun (at least 4-6 hours) | Keep consistently moist; check baskets daily in hot weather | 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 |
| 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 Chalice Vine | Direct sun (at least 4-6 hours) | Weekly during the growing season; fortnightly in winter | 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-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-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-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 |
| Longan | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries; keep steady in growth | Mildly toxic to pets |
| Longan | Direct sun (at least 4-6 hours) | Every 5–7 days for young trees; every 10–14 days once established | 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 |
| Longleaf Phlox | Direct sun (at least 4-6 hours) | Every 14–21 days when establishing; minimal supplemental water once established | Pet-safe |
| 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 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 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 |
| Loquat | Direct sun (at least 4-6 hours) | Deeply when the top 5 cm of soil dries, roughly weekly in warm growth, less in winter | Mildly 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 |
| 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 |
| Love-lies-bleeding | 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 |
| Loving Touch Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 2-4 days in summer | Pet-safe |
| 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 |
| 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 |
| Lychee | Direct sun (at least 4-6 hours) | Keep evenly moist in growth; water when the top 3-5 cm dries | Mildly toxic to pets |
| 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 |
| 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 |
| Lythrum salicaria | Direct sun (at least 4-6 hours) | Keep wet; thrives in saturated soil and shallow water | Mildly toxic to pets |
| MacDonnell Ranges Cycad | Direct sun (at least 4-6 hours) | Every 3–4 weeks (established); monthly or less in winter | Toxic to pets |
| Mackay's Heath | Direct sun (at least 4-6 hours) | Regular; keep soil consistently moist | Mildly toxic to pets |
| Madagascar Palm | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; once or twice monthly in winter | Toxic to pets |
| Madagascar Palm Geay | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; once or twice per month in winter | Toxic to pets |
| Madagascar Periwinkle (Vinca) | Direct sun (at least 4-6 hours) | When the top 2-3 cm (1 in) of soil is dry, roughly weekly | Toxic to pets |
| Madagascar Sundew | Direct sun (at least 4-6 hours) | Continuously — maintain 1–3 cm of water in a tray year-round during active growth; reduce tray depth in winter. | Pet-safe |
| 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 |
| Madonna Lily | Direct sun (at least 4-6 hours) | Moderate; water during active growth, reduce as dormancy approaches | Toxic to pets |
| 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 |
| 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 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 |
| Maiden Grass | Direct sun (at least 4-6 hours) | Weekly during the first growing season; every 2–3 weeks once established | 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 |
| Malabar Quisqualis | Direct sun (at least 4-6 hours) | Every 3–5 days during dry periods; reduce in cool or wet seasons | Mildly toxic to pets |
| Malay Apple | Direct sun (at least 4-6 hours) | Deep watering every 4-7 days; keep consistently moist when fruiting | Mildly toxic to pets |
| Malepartus silver grass | Direct sun (at least 4-6 hours) | Weekly during the growing season; reduce in autumn; minimal in winter | Pet-safe |
| 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 |
| Mamey Apple | Direct sun (at least 4-6 hours) | 2–3 times per week; reduce in winter | Mildly toxic to pets |
| Mamey Sapote | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-9 days in growth | Mildly 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 |
| Mamoncillo | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-12 days once established | Mildly toxic to pets |
| 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 |
| Mandevilla 'Alice du Pont' | Direct sun (at least 4-6 hours) | Keep evenly moist in summer; water when the top 2-3 cm of soil dries, often every 2-4 days in heat | Mildly toxic to pets |
| Mandevilla 'Sun Parasol Crimson' | 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 |
| 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 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 Heath | Direct sun (at least 4-6 hours) | Moderate to infrequent; drought-tolerant once established | 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-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 |
| Marang | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil begins to dry, often every 3-6 days in warm growth | Mildly toxic to pets |
| Marble Houseleek | Direct sun (at least 4-6 hours) | Every 2–4 weeks in growing season; once a month or less in winter | 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 |
| 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 |
| 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 |
| Marigold | Direct sun (at least 4-6 hours) | When the top of the soil is dry, every 5-7 days | Mildly toxic to pets |
| 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 |
| 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 |
| 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 |
| 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 |
| Masters' Larch | Direct sun (at least 4-6 hours) | Weekly during first 2 years; monthly once established | Pet-safe |
| 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 |
| Mato Grosso Milfoil | Direct sun (at least 4-6 hours) | Permanently submerged aquatic stem plant | Pet-safe |
| Matsumoto Mix aster | Direct sun (at least 4-6 hours) | 2–3 times per week in warm weather; reduce in cool or overcast periods | Pet-safe |
| 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 |
| Matted Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–3 weeks; very sparingly in winter | Pet-safe |
| 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) | Keep evenly moist in growth; water when the top 3-5 cm dries | Mildly toxic to pets |
| 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 |
| Maximilian Sunflower | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; minimal supplemental irrigation needed | Pet-safe |
| May Night Salvia | Direct sun (at least 4-6 hours) | When top 3-5 cm of soil is dry, roughly every 7-10 days once established | Pet-safe |
| 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 |
| MD-2 Gold Pineapple | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries out, roughly every 7-10 days | Pet-safe |
| Meadow Blazing Star | Direct sun (at least 4-6 hours) | Keep evenly moist to medium; water during dry spells | Pet-safe |
| Meadow Buttercup | Direct sun (at least 4-6 hours) | Naturally thrives in moist conditions; water weekly in dry spells | Toxic to pets |
| 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 Oat Grass | Direct sun (at least 4-6 hours) | Low; very drought-tolerant | Pet-safe |
| Meadow Phlox | Direct sun (at least 4-6 hours) | 1-2 times per week; prefers consistently moist soil | Mildly toxic to pets |
| Mealy-cup Sage | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-7 days when young; every 10-14 days once established | Pet-safe |
| Mealycup Sage 'Victoria Blue' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; roughly weekly, less once established | Pet-safe |
| Mediterranean Everlasting | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established | Mildly toxic to pets |
| 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 |
| Mediterranean Sea Holly | Direct sun (at least 4-6 hours) | Low — water young plants to establish, then rely on rainfall | Pet-safe |
| Melocactus bahiensis | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 1-2 weeks in warm summer growth; sparingly in winter | Mildly toxic to pets |
| Melocactus peruvianus | Direct sun (at least 4-6 hours) | When soil is completely dry, about every 1-2 weeks in warm summer growth; minimal in winter | Mildly toxic to pets |
| 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 Cypress | Direct sun (at least 4-6 hours) | Weekly during establishment; fortnightly in dry periods once mature | Mildly toxic to pets |
| Mexican Fan Palm | Direct sun (at least 4-6 hours) | Deeply but infrequently once established, every 10-14 days; weekly while young | 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 Hat | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; very drought-tolerant | Pet-safe |
| 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 Orange Sage | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil dries out, roughly every 5-8 days during the growing season | 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 sunflower | Direct sun (at least 4-6 hours) | Weekly until established; then every 10–14 days; drought-tolerant once mature | Mildly toxic to pets |
| Mexican zinnia | Direct sun (at least 4-6 hours) | Once or twice weekly; allow the top 2–3 cm of soil to dry between waterings | 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 |
| Midas Touch Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during growth | 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 |
| 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 |
| Million Bells 'Superbells' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry — let it dry slightly between waterings | Pet-safe |
| 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 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 |
| Miniature Desert Rose | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; once a month or less in winter | Pet-safe |
| 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 Willmott's Ghost | Direct sun (at least 4-6 hours) | Low — once established, water only during prolonged drought | 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 Coneflower | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; very drought-tolerant | 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 |
| Missouri Ironweed | Direct sun (at least 4-6 hours) | Moderate to high — prefers moist soil | Mildly toxic to pets |
| Mister Lincoln Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | 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 |
| 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 |
| Mombasa Cycad | Direct sun (at least 4-6 hours) | Every 1–3 weeks in the growing season; every 4–6 weeks in winter | 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 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 fully dry, about every 2-3 weeks in the growing season; keep dry in winter | Pet-safe |
| 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 Comb Vine | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; reduce in cooler or drier months | Mildly toxic to pets |
| Monkey Jack | Direct sun (at least 4-6 hours) | Water young trees 2–3 times per week; established trees are moderately drought-tolerant and generally managed on natural rainfall in tropical climates. | 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 |
| Montpellier Rock Rose | Direct sun (at least 4-6 hours) | Low — establishment watering only | Mildly toxic to pets |
| Moonflower | Direct sun (at least 4-6 hours) | Weekly, more often in hot or dry spells | Toxic to pets |
| Moonglow Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days when establishing, then deep occasional soaks | Mildly toxic to pets |
| Moorcroft's Sage | Direct sun (at least 4-6 hours) | Moderate during growth; minimal in winter | Pet-safe |
| Mops Dwarf Mountain Pine | Direct sun (at least 4-6 hours) | Every 10–14 days in summer once established; minimal in winter | 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 Sea Holly | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established, water sparingly in winter | 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 |
| Moso Bamboo | Direct sun (at least 4-6 hours) | 2–3 times per week in the growing season; weekly in winter | Pet-safe |
| Mosquito Plant | Direct sun (at least 4-6 hours) | Every 7–14 days once established; more frequent when young | Pet-safe |
| Moss Campion | Direct sun (at least 4-6 hours) | Sparingly in summer; almost none in winter | Pet-safe |
| Moss Phlox | Direct sun (at least 4-6 hours) | Moderate — water during establishment and dry spells | Pet-safe |
| Moss rose | Direct sun (at least 4-6 hours) | When the soil is thoroughly dry, roughly every 7-10 days in summer | Toxic to pets |
| 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 |
| 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 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 Everlasting | Direct sun (at least 4-6 hours) | Every 2–3 weeks during growing season; minimal in winter | Pet-safe |
| 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 Pine | Direct sun (at least 4-6 hours) | When the soil surface starts to dry, then soak thoroughly | Mildly toxic to pets |
| Mountain Sandwort | Direct sun (at least 4-6 hours) | Weekly during establishment; drought-tolerant once established | Pet-safe |
| Mountain Soursop | Direct sun (at least 4-6 hours) | Twice weekly when establishing; weekly once mature | 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 |
| Mountain Turk's Cap | Direct sun (at least 4-6 hours) | 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 |
| Mouse-ear Hawkweed | Direct sun (at least 4-6 hours) | Infrequent — allow soil to dry between waterings | Mildly toxic to pets |
| Mousetail Arum | Direct sun (at least 4-6 hours) | Water moderately during autumn-to-spring growth when the top few cm dry; keep dry through summer dormancy | Toxic to pets |
| 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 |
| Mrs D.F. Maxwell Cornish heath | Direct sun (at least 4-6 hours) | Weekly while establishing; every 2–3 weeks once established | Pet-safe |
| 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 |
| Muhly Grass | Direct sun (at least 4-6 hours) | Water regularly the first season to establish, then only in drought, roughly every 2 weeks | 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 | 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 |
| Munby's Rock Rose | Direct sun (at least 4-6 hours) | Very low — drought-tolerant once established | Mildly toxic to pets |
| Munstead Wood Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| 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 |
| Muster-John-Henry | Direct sun (at least 4-6 hours) | Once or twice weekly; allow the top 3 cm of soil to dry between waterings | Mildly toxic to pets |
| 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 |
| Nahoum's Alcantarea | Direct sun (at least 4-6 hours) | Refill the central tank every 7-10 days; water substrate sparingly — only when completely dry | Pet-safe |
| Nam Doc Mai Mango | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, roughly every 5-10 days in growth | Pet-safe |
| 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 |
| Nance | Direct sun (at least 4-6 hours) | Every 14–21 days; highly drought-tolerant when established | Pet-safe |
| 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 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 |
| 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 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 Zinnia | Direct sun (at least 4-6 hours) | When top 3-4 cm of soil is dry, roughly every 5-10 days | 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 Evening Primrose | Direct sun (at least 4-6 hours) | Every 10–14 days; very drought-tolerant once established | 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-petal Frangipani | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; minimal in winter dormancy | 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 |
| Narrowleaf Milkweed | Direct sun (at least 4-6 hours) | Low; drought-tolerant, minimal supplemental watering | 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 |
| Nasturtium | Direct sun (at least 4-6 hours) | Weekly watering | 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 Plum Bonsai | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-6 days in growth | Pet-safe |
| 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 |
| 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 |
| Nearly Wild Rose | Direct sun (at least 4-6 hours) | Deeply once a week, more in heat | Pet-safe |
| Needle Grass | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| 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 |
| Nelumbo 'Baby Doll' | Direct sun (at least 4-6 hours) | Always submerged; keep 8-25 cm of water over the crown | Mildly toxic to pets |
| Nelumbo 'Momo Botan' | Direct sun (at least 4-6 hours) | Always submerged; keep 10-30 cm of water over the crown | Mildly toxic to pets |
| Nelumbo 'Mrs. Perry D. Slocum' | Direct sun (at least 4-6 hours) | Always submerged; keep 15-45 cm of water over the crown | Mildly toxic to pets |
| Nelumbo lutea | Direct sun (at least 4-6 hours) | Always submerged; keep 15-60 cm of standing water over the crown | Mildly toxic to pets |
| Nelumbo nucifera | Direct sun (at least 4-6 hours) | Permanently submerged rhizome in still water with warm emergent growth | 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 |
| 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 |
| Nerved Catmint | Direct sun (at least 4-6 hours) | Every 7–10 days in the growing season; much less in winter | Pet-safe |
| Nery's Turk's Cap | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer; reduce to every 4 weeks in winter | Pet-safe |
| Netted Iris | Direct sun (at least 4-6 hours) | Low — dry in summer dormancy; moderate when in growth | Toxic to pets |
| 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 |
| 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 Mexico Giant Hyssop | Direct sun (at least 4-6 hours) | Every 7–14 days once established | Pet-safe |
| 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 Ironweed | Direct sun (at least 4-6 hours) | Keep consistently moist; water weekly when rainfall is short | Mildly toxic to pets |
| New Zealand Everlasting Daisy | Direct sun (at least 4-6 hours) | Occasional; tolerant of dry spells once established | Mildly toxic to pets |
| Nicotiana × sanderae 'Starmaker Lime' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | Toxic to pets |
| Nicotiana alata 'Perfume Deep Purple' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | 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-scented stock | Direct sun (at least 4-6 hours) | Every 7–10 days; allow soil to dry between waterings | Pet-safe |
| Nihoa Palm | Direct sun (at least 4-6 hours) | When the top 5-7 cm of soil is dry, roughly every 10-21 days | Pet-safe |
| Nikko Fir | Direct sun (at least 4-6 hours) | Weekly when establishing; reduced once established | Pet-safe |
| Ninebark 'Diabolo' | Direct sun (at least 4-6 hours) | Weekly while establishing; established plants only in prolonged drought | Mildly toxic to pets |
| Nipa Palm | Direct sun (at least 4-6 hours) | Keep constantly moist to wet; does not tolerate drying out | Pet-safe |
| Noble Fir | Direct sun (at least 4-6 hours) | Regular watering during establishment; naturally sustained by Pacific Northwest rainfall | Pet-safe |
| Nodding Sage | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to dry between waterings | Pet-safe |
| 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 |
| Noni | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out, about every 5-7 days | Mildly toxic to pets |
| Nootka Cypress | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | 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 |
| Northern Blazing Star | Direct sun (at least 4-6 hours) | Every 1-2 weeks once established; more often during establishment | 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 |
| 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 |
| Northwind Switchgrass | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks when mature | Pet-safe |
| 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 |
| Notocactus Magnificus | Direct sun (at least 4-6 hours) | Soak-and-dry: water deeply only when the mix is completely dry, roughly every 10-14 days in summer | Mildly toxic to pets |
| 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 |
| Nymphaea 'Albert Greenberg' | Direct sun (at least 4-6 hours) | Permanently submerged in warm still water | Mildly toxic to pets |
| Nymphaea 'Attraction' | Direct sun (at least 4-6 hours) | Permanently submerged; maintain pond level, top up in summer heat | Mildly toxic to pets |
| Nymphaea 'Chromatella' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level steady | Mildly toxic to pets |
| Nymphaea 'Director George T. Moore' | Direct sun (at least 4-6 hours) | Permanently submerged in warm still water | Mildly toxic to pets |
| Nymphaea 'Escarboucle' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level constant | Mildly toxic to pets |
| Nymphaea 'Firecrest' | Direct sun (at least 4-6 hours) | Permanently submerged in still water | Mildly toxic to pets |
| Nymphaea 'Gonnere' | Direct sun (at least 4-6 hours) | Permanently submerged in still or very slow-moving water | Mildly toxic to pets |
| Nymphaea 'James Brydon' | Direct sun (at least 4-6 hours) | Permanently submerged; maintain steady pond level | Mildly toxic to pets |
| Nymphaea 'Marliacea Albida' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level steady | Mildly toxic to pets |
| Nymphaea 'Marliacea Carnea' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level steady | Mildly toxic to pets |
| Nymphaea 'Perry's Fire Opal' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level steady | Mildly toxic to pets |
| Nymphaea 'Pygmaea Helvola' | Direct sun (at least 4-6 hours) | Permanently submerged in shallow still water | Mildly toxic to pets |
| Nymphaea 'Pygmaea Rubra' | Direct sun (at least 4-6 hours) | Permanently submerged in shallow still water | Mildly toxic to pets |
| Nymphaea 'Sioux' | Direct sun (at least 4-6 hours) | Permanently submerged; keep pond level steady | Mildly toxic to pets |
| Nymphaea capensis | Direct sun (at least 4-6 hours) | Permanently submerged in warm still water | Mildly toxic to pets |
| Nymphoides indica | Direct sun (at least 4-6 hours) | Permanently submerged; keep warm and topped up | Mildly toxic to pets |
| Nymphoides peltata | Direct sun (at least 4-6 hours) | Permanently submerged; maintain stable pond level | Mildly toxic to pets |
| Nyssa sylvatica | Direct sun (at least 4-6 hours) | Weekly while establishing; keep soil moist to wet | Mildly toxic to pets |
| 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 |
| Ohio Goldenrod | Direct sun (at least 4-6 hours) | Moderate to high — keep soil consistently moist | Pet-safe |
| Oklahoma Salmon zinnia | Direct sun (at least 4-6 hours) | Every 3–5 days; adjust for rainfall and temperature | Pet-safe |
| 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 Cactus | Direct sun (at least 4-6 hours) | Roughly weekly in spring-summer growth; keep nearly dry in winter | Pet-safe |
| Old Lady Pincushion | Direct sun (at least 4-6 hours) | When the mix is completely dry, roughly every 2-3 weeks in summer; keep nearly dry in winter | Pet-safe |
| 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 Cactus | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 2-3 weeks in summer, very little 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 Palm | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 10-14 days | Pet-safe |
| 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 Man's Beard | Direct sun (at least 4-6 hours) | During establishment water deeply every 5-7 days; once established, water only during prolonged dry spells | Toxic to pets |
| 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 World Sago Cycad | Direct sun (at least 4-6 hours) | When the top 5 cm of mix is dry, roughly every 12-16 days in growth | Toxic to pets |
| 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 |
| Olivia Rose Austin | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| Olympiad Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during growth | 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 |
| Onzuka Bishop's Cap | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth; none in winter | Pet-safe |
| 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 |
| 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 Clock Vine | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 6-8 days in summer | Pet-safe |
| Orange coneflower | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| 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 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 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-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 |
| Oreocereus trollii | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 10-14 days in active growth; none in winter | Pet-safe |
| Organ Pipe Cactus | Direct sun (at least 4-6 hours) | When fully dry, about every 2 weeks in summer; keep dry in winter | Mildly toxic to pets |
| Oriental Arborvitae | Direct sun (at least 4-6 hours) | Weekly when establishing (first 1–2 seasons); every 2–3 weeks once established; reduce in winter | Mildly toxic to pets |
| Oriental Bittersweet | Direct sun (at least 4-6 hours) | Extremely drought-tolerant once established; supplemental watering is rarely needed except in the first season | Toxic to pets |
| oriental fountain grass | Direct sun (at least 4-6 hours) | Every 10–14 days once established; more frequent during establishment | Pet-safe |
| Oriental Hornbeam | Direct sun (at least 4-6 hours) | Low once established; water during first 2 seasons only | Pet-safe |
| Oriental Poppy 'Beauty of Livermere' | Direct sun (at least 4-6 hours) | Once a week during active growth; reduce as plants go summer-dormant | Toxic to pets |
| Oriental Poppy 'Patty's Plum' | Direct sun (at least 4-6 hours) | Once a week during spring growth; reduce markedly as summer dormancy approaches | Toxic to pets |
| Oriental Spruce | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; regular moisture during first 2–3 years | Mildly toxic to pets |
| 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 | 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 |
| Orpine | Direct sun (at least 4-6 hours) | Every 1–2 weeks during dry spells; drought-tolerant once established | Mildly toxic to pets |
| Osbeck's Rock Rose | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | 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 |
| 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 |
| Oxeye daisy | Direct sun (at least 4-6 hours) | Minimal once established; water during prolonged drought only | 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 |
| Pachyphytum bracteosum | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in growth, sparingly in winter | Pet-safe |
| Pachyphytum compactum | Direct sun (at least 4-6 hours) | When soil is bone dry, about every 2 weeks in growth and rarely in winter | Pet-safe |
| Pachyphytum glutinicaule | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer, very sparingly in winter | Pet-safe |
| Pachyphytum hookeri | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 10-14 days in active growth, minimal in winter | Pet-safe |
| Pachyphytum werdermannii | Direct sun (at least 4-6 hours) | When soil is bone dry, roughly every 2 weeks in growth, rarely in winter | Pet-safe |
| Pachyveria 'Clavifolia' | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in growth, sparingly in winter | Pet-safe |
| Pachyveria 'Exotica' | Direct sun (at least 4-6 hours) | When soil is fully dry, about every 10-14 days in growth, minimal in winter | Pet-safe |
| 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 |
| Pachyveria 'Powder Puff' | Direct sun (at least 4-6 hours) | When soil is fully dry, roughly every 10-14 days in growth, sparingly in winter | Pet-safe |
| Pacific Fan Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Pacifica Vinca | Direct sun (at least 4-6 hours) | Every 3–5 days outdoors in summer heat; allow topsoil to partially dry between waterings | Toxic to pets |
| Paddle Plant (Flapjacks) | Direct sun (at least 4-6 hours) | Every 2-3 weeks in spring/summer; roughly monthly or less in winter | Toxic to pets |
| 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 |
| Painted Daisy | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce after flowering and in winter | Mildly toxic to pets |
| Painted Echeveria | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 10-14 days in growth | Pet-safe |
| 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 |
| 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-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 |
| Palmer's Indian Mallow | Direct sun (at least 4-6 hours) | Low; deep, infrequent irrigation once established | Mildly toxic to pets |
| Palo Alto Sweetgum | Direct sun (at least 4-6 hours) | Regular in first 2–3 years; moderate once established | Mildly toxic to pets |
| Palo Santo | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; monthly or less in winter | 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 | Direct sun (at least 4-6 hours) | Every 5–7 days; allow topsoil to dry slightly between waterings | Mildly toxic to pets |
| 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 Plant | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer | Toxic to pets |
| 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 |
| Papaya | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil is dry; consistent moisture without saturation, often every 3-5 days in warmth | Mildly toxic to pets |
| 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 |
| Paprika yarrow | Direct sun (at least 4-6 hours) | Water when top 5–8 cm of soil is dry; drought-tolerant once established | Mildly toxic to pets |
| Parrot Gladiolus | Direct sun (at least 4-6 hours) | Weekly during active growth; reduce once foliage yellows; cease during summer dormancy | Toxic to pets |
| Parrot Pitcher Plant | Direct sun (at least 4-6 hours) | Keep permanently wet, standing in 1-3 cm of water (tray method); it tolerates brief flooding well | 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 |
| Parsons Juniper | Direct sun (at least 4-6 hours) | Water deeply during the first season; afterward only in extended drought | Toxic to pets |
| Partridge Pea | Direct sun (at least 4-6 hours) | Low; water during establishment then rely on rainfall | Mildly toxic to pets |
| 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 |
| Path Rush | Direct sun (at least 4-6 hours) | Minimal supplemental watering needed once established; tolerates periodic flooding and 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 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 |
| Pazazz Mix Portulaca | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, roughly every 7-14 days | Mildly toxic to pets |
| Peace Rose | Direct sun (at least 4-6 hours) | Deeply 1-2 times per week, more in heat | Pet-safe |
| 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 |
| Peanut Cactus | Direct sun (at least 4-6 hours) | Every 1-3 weeks in spring/summer; roughly monthly or less in winter | Pet-safe |
| 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 |
| Peculiar Cheiridopsis | Direct sun (at least 4-6 hours) | Every 2–3 weeks in autumn–spring; none in summer | Pet-safe |
| Pedalai | Direct sun (at least 4-6 hours) | Water 3–4 times per week for young trees; established trees in ground need weekly deep irrigation supplemented by natural rainfall. | 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-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-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 |
| Penelope Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | Pet-safe |
| Penisetum massaicum Red Bunny Tails | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about weekly; more often in pots and heat | Pet-safe |
| 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 | Direct sun (at least 4-6 hours) | Deep watering once a week in dry spells | 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 |
| Pepino Dulce | Direct sun (at least 4-6 hours) | Keep evenly moist; water deeply every 2-4 days in summer, more in containers | Toxic to pets |
| 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 |
| Perez's Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established; less 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 Carpet zinnia | Direct sun (at least 4-6 hours) | Every 5–7 days; highly drought tolerant once established | Pet-safe |
| Persian Catmint | Direct sun (at least 4-6 hours) | Every 7–14 days; less in cooler seasons | 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 |
| 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 Apple Cactus | Direct sun (at least 4-6 hours) | Every 2-3 weeks in spring/summer; roughly monthly or less in winter | Pet-safe |
| Peruvian bougainvillea | Direct sun (at least 4-6 hours) | Every 7–10 days in active growth; every 3–4 weeks when dry-stressed to trigger blooming | Mildly toxic to pets |
| Peruvian Canna | Direct sun (at least 4-6 hours) | Keep soil consistently moist; water every 4-6 days in summer | Pet-safe |
| 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 zinnia | Direct sun (at least 4-6 hours) | Once or twice weekly; allow the top 3 cm of soil to dry between waterings | Pet-safe |
| Petunia | Direct sun (at least 4-6 hours) | Even moisture — every 1-2 days for hanging baskets in heat | Pet-safe |
| 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 | Direct sun (at least 4-6 hours) | Sparingly: only when soil is fully dry, roughly every 2-3 weeks in summer, none in winter | Toxic to pets |
| Pheasant Tail Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; drought-tolerant thereafter | Mildly toxic to pets |
| 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 drummondii 'Intensia Cabernet' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days | 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 |
| 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 |
| 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 |
| Pineleaf Penstemon | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; rarely in winter | Pet-safe |
| Pinemat manzanita | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to dry between waterings once established | Pet-safe |
| Ping Pong Purple globe amaranth | Direct sun (at least 4-6 hours) | Every 5–7 days; allow soil surface to dry slightly | Pet-safe |
| 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 Dipladenia | Direct sun (at least 4-6 hours) | Every 5–7 days in summer; every 10–14 days in winter | Mildly toxic to pets |
| Pink Evening Primrose | Direct sun (at least 4-6 hours) | Every 1–2 weeks once established; less in cool periods | Mildly toxic to pets |
| 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 Mandevilla | Direct sun (at least 4-6 hours) | 2-3 times per week in active growth, every 10-14 days in winter | Mildly toxic to pets |
| Pink mountain heather | Direct sun (at least 4-6 hours) | Consistently moist throughout the growing season; less in winter | 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 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 Rain Lily | Direct sun (at least 4-6 hours) | Regular in summer; minimal in winter | Mildly toxic to pets |
| Pink Rock Jasmine | Direct sun (at least 4-6 hours) | Very sparingly; driest in winter | Pet-safe |
| Pink Senecio | Direct sun (at least 4-6 hours) | regular during the growing season, reduced in winter | Toxic to pets |
| Pink Storm Lily | Direct sun (at least 4-6 hours) | Moderate in summer growth; minimal in winter | Toxic to pets |
| Pink Surprise calendula | Direct sun (at least 4-6 hours) | Every 5–7 days; reduce in cool, wet periods | Pet-safe |
| Pink Tritonia | Direct sun (at least 4-6 hours) | Moderate during growth; dry to minimal in winter dormancy | Mildly toxic to pets |
| 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 |
| Pirri-Pirri Bur | Direct sun (at least 4-6 hours) | Fortnightly once established; drought-tolerant | Pet-safe |
| Pistia stratiotes | Direct sun (at least 4-6 hours) | Floats permanently on water; keep the water body topped up and the rosette crown dry | Toxic to pets |
| 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 |
| Pitomba | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil dries, roughly weekly; keep young plants more consistently moist | Mildly toxic to pets |
| Pitton's Houseleek | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly or less in winter | Pet-safe |
| 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 Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established | Mildly toxic to pets |
| Playboy Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | 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 |
| 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 |
| Ploughman's Spikenard | Direct sun (at least 4-6 hours) | Low — water every 2–3 weeks in dry spells once established | Mildly toxic to pets |
| Plumed cockscomb | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days in summer | Pet-safe |
| 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 |
| Pogge's Cycad | Direct sun (at least 4-6 hours) | Every 2–3 weeks in summer; monthly in winter | Toxic to pets |
| Point Reyes bearberry | Direct sun (at least 4-6 hours) | Low once established; water weekly for the first 1–2 seasons | Pet-safe |
| Poisonous Adenia | Direct sun (at least 4-6 hours) | Every 2–4 weeks during summer growing season; completely withheld in winter | Toxic to pets |
| 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 |
| Pomelo | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, about every 5-10 days | Toxic to pets |
| Pompon Dahlia 'Jowey Mirella' | Direct sun (at least 4-6 hours) | Deeply 2-3 times a week in summer once established; keep evenly moist while flowering | Toxic to pets |
| Pond Apple | Direct sun (at least 4-6 hours) | Keep soil consistently moist to wet; tolerates periodic flooding | 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 |
| Ponytail palm | Direct sun (at least 4-6 hours) | When the soil is bone dry, every 2-3 weeks | Pet-safe |
| Poplar-Leaved Rock Rose | Direct sun (at least 4-6 hours) | Low — establishment watering then rain-fed | Mildly toxic to pets |
| Poppy Anemone | Direct sun (at least 4-6 hours) | Moderate in spring, dry in summer | 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 |
| Portulaca grandiflora 'Sundial Mango' | Direct sun (at least 4-6 hours) | When the soil is dry several centimetres down, roughly every 7-10 days; less in cool spells | Toxic to pets |
| Portulaca oleracea 'Fairytales Cinderella' | Direct sun (at least 4-6 hours) | When the soil has dried several centimetres down, about every 7-10 days; more often only in extreme heat | Toxic to pets |
| Potomac Early snapdragon | Direct sun (at least 4-6 hours) | 2-3 times per week | Mildly toxic to pets |
| Pouched Catasetum | Direct sun (at least 4-6 hours) | Daily during active growth; stop completely during dormancy | Pet-safe |
| 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 |
| Powdery Thalia | Direct sun (at least 4-6 hours) | Permanent standing water or saturated soil; 15–45 cm over crown | Mildly toxic to pets |
| PowWow Wild Berry coneflower | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2 weeks once established in dry spells | 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 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 Dropseed | Direct sun (at least 4-6 hours) | Water regularly the first year to establish, then only in extended drought, roughly every 2-3 weeks | Mildly toxic to pets |
| 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 Goldenrod | Direct sun (at least 4-6 hours) | Low — water only to establish; drought-tolerant once rooted | Pet-safe |
| Prairie Heart-Leaved Aster | Direct sun (at least 4-6 hours) | Low to moderate — drought tolerant | Pet-safe |
| Prairie June Grass | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; withhold water during summer dormancy | Pet-safe |
| Prairie Milkweed | Direct sun (at least 4-6 hours) | Moderate; tolerates moist conditions better than most milkweeds | Toxic to pets |
| Prairie Penstemon | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; weekly during establishment | Pet-safe |
| 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 Sky Switchgrass | Direct sun (at least 4-6 hours) | Weekly during first season; every 2–3 weeks once established | Pet-safe |
| 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 |
| 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 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 Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks; minimal watering in winter | Mildly toxic to pets |
| 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 |
| Prince of Wales Juniper | Direct sun (at least 4-6 hours) | Every 7-10 days while establishing, then minimal | Mildly toxic to pets |
| Prince's feather | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil is dry, roughly every 7 days in summer | 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 |
| Princess Flower | Direct sun (at least 4-6 hours) | Roughly weekly; keep the soil evenly moist | Mildly toxic to pets |
| Profusion orange zinnia | Direct sun (at least 4-6 hours) | Every 5–7 days once established; more frequently in pots or extreme heat | Pet-safe |
| Profusion White Zinnia | 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 |
| Prosperity Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season, more in heat | Pet-safe |
| Prostrate Blue Noble Fir | Direct sun (at least 4-6 hours) | Weekly when young, drought-tolerant once established | Mildly toxic to pets |
| Prostrate Speedwell | Direct sun (at least 4-6 hours) | Every 10–14 days; drought-tolerant once established | 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 |
| 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 |
| Pulasan | Direct sun (at least 4-6 hours) | Regular watering every 3-7 days; keep soil evenly moist | Mildly toxic to pets |
| Pulasan | Direct sun (at least 4-6 hours) | Every 3–5 days for young trees; every 7–10 days for established trees during dry periods | Mildly toxic to pets |
| 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 |
| Pumila Pampas Grass | Direct sun (at least 4-6 hours) | Deeply once per week during the first growing season; established plants can survive on rainfall in most temperate climates | Mildly toxic to pets |
| 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 |
| Purity cosmos | Direct sun (at least 4-6 hours) | Every 5–7 days; highly drought tolerant once established | Pet-safe |
| Purple Allamanda | Direct sun (at least 4-6 hours) | Every 3–5 days during active growth; reduce to weekly or less in cooler months | Toxic to pets |
| Purple Cliff Brake | Direct sun (at least 4-6 hours) | every 2-3 weeks | Mildly toxic to pets |
| 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 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 Glory Tree | Direct sun (at least 4-6 hours) | Water regularly in spring and summer to keep soil consistently moist; reduce in cooler months. | Mildly toxic to pets |
| 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 Love Grass | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; more frequent during the first growing season | Pet-safe |
| Purple Milkweed | Direct sun (at least 4-6 hours) | Keep evenly moist; water during dry periods, especially while establishing | Toxic to pets |
| Purple mountain heather | Direct sun (at least 4-6 hours) | Regularly; maintain consistent moisture throughout the growing season | Mildly toxic to pets |
| Purple Mullein | Direct sun (at least 4-6 hours) | Every 7–10 days during active growth and dry spells | Mildly toxic to pets |
| Purple Needlegrass | Direct sun (at least 4-6 hours) | Very low; summer-dry, winter-wet cycle | Pet-safe |
| 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 to wet; stand the pot in 1-2 cm of water during the growing season | 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 Queen bougainvillea | Direct sun (at least 4-6 hours) | Every 7–14 days in active growth; withhold to 3–4 week intervals to trigger blooming | Mildly toxic to pets |
| Purple Rose Tree | Direct sun (at least 4-6 hours) | Every 1–2 weeks in autumn and winter (active growing season); reduce to monthly or suspend in summer dormancy | Mildly toxic to pets |
| 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 |
| 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 |
| Pygmy Rwandan Water Lily | Direct sun (at least 4-6 hours) | Keep roots in very shallow, warm, constantly moist conditions — water depth 1–3 cm over the substrate | Mildly toxic to pets |
| 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 Torch Amaranth | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | 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 Merendera | Direct sun (at least 4-6 hours) | Minimal; naturally dry in summer | Toxic to pets |
| Pyrenean Rock Jasmine | Direct sun (at least 4-6 hours) | Low — water from below and keep dry in winter | 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 Elizabeth Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly, when the top few centimetres of soil are dry | Pet-safe |
| Queen Lime Red zinnia | Direct sun (at least 4-6 hours) | Regular; deep watering 2–3 times per week at soil level only | Pet-safe |
| Queen Mix Spider Flower | 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 |
| 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 Sweden Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | Pet-safe |
| 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 Pineapple | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil is dry, about every 7-10 days | Pet-safe |
| 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 |
| Queeny Lime Orange zinnia | Direct sun (at least 4-6 hours) | Every 3–5 days in warm weather; reduce in cool spells | Pet-safe |
| 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 |
| 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 |
| Rainbow Plant | Direct sun (at least 4-6 hours) | Keep substrate consistently wet using the tray method | Mildly toxic to pets |
| Rainer's Bellflower | Direct sun (at least 4-6 hours) | Moderately during growth; sparingly in winter | Pet-safe |
| Ram's Head Catasetum | Direct sun (at least 4-6 hours) | Heavily during growth; completely stopped during leafless dormancy | Pet-safe |
| Rambai | Direct sun (at least 4-6 hours) | 2–3 times per week; more frequent in dry season | Mildly toxic to pets |
| Rambutan | Direct sun (at least 4-6 hours) | Regular watering every 3-7 days; keep soil evenly moist year-round | Mildly toxic to pets |
| Rangoon Creeper | Direct sun (at least 4-6 hours) | Regularly during active growth — roughly every 3–5 days; reduce in winter | 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 |
| 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 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 |
| 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 |
| Rechinger's Rosularia | Direct sun (at least 4-6 hours) | Every 2–4 weeks in the growing season; very rarely in winter | Pet-safe |
| 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 amaranth | Direct sun (at least 4-6 hours) | Every 7–10 days once established | Mildly 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 Banana | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil is dry, every 2-4 days in active growth | Pet-safe |
| Red Cabomba | Direct sun (at least 4-6 hours) | Fully submerged aquatic; maintain in aquarium water continuously | Pet-safe |
| Red Clockvine | Direct sun (at least 4-6 hours) | Every 3–5 days during active growth; reduce in winter | Mildly toxic to pets |
| 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 Fir | Direct sun (at least 4-6 hours) | Regular moisture; does not tolerate summer drought well | Pet-safe |
| Red Frangipani | Direct sun (at least 4-6 hours) | Water deeply when the soil is dry to touch (roughly every 7–10 days in summer); withhold almost completely in winter dormancy | Mildly toxic to pets |
| red head fountain grass | Direct sun (at least 4-6 hours) | Every 7–10 days during the growing season; reduce in autumn; minimal in winter | Pet-safe |
| Red Horned Poppy | Direct sun (at least 4-6 hours) | Rarely; only during prolonged drought | Toxic to pets |
| 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 Indian Water Lily | Direct sun (at least 4-6 hours) | Permanently submerged — maintain 25–50 cm of water over the crown | Mildly toxic to pets |
| Red Indian Water Lily | Direct sun (at least 4-6 hours) | Fully aquatic; roots and rhizome submerged, leaves and flowers floating or emergent | Mildly toxic to pets |
| Red Lady Papaya | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil is dry; steady moisture without saturation, often every 3-5 days in warmth | Mildly toxic to pets |
| 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 Margin Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week during establishment; weekly once mature | Pet-safe |
| Red Mombin | Direct sun (at least 4-6 hours) | Every 10–21 days; drought-tolerant when established | Pet-safe |
| Red morning glory | Direct sun (at least 4-6 hours) | Once or twice a week; drought-tolerant when established | Toxic to pets |
| 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 Passion Flower | Direct sun (at least 4-6 hours) | Water thoroughly when the top 3-4 cm of soil dries out, roughly every 5-8 days; reduce in winter | 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 Ray Switchgrass | Direct sun (at least 4-6 hours) | Every 1-2 weeks when established | Pet-safe |
| Red Riding Hood Mandevilla | Direct sun (at least 4-6 hours) | Every 2-3 days in summer when actively blooming, reduce to every 10-14 days in winter | 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 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 Spider Lily | Direct sun (at least 4-6 hours) | Water sparingly; let the bulb go bone-dry during summer dormancy | Toxic to pets |
| Red Spruce | Direct sun (at least 4-6 hours) | Weekly in dry periods; naturally receives adequate moisture in humid northeastern climates | Pet-safe |
| Red Star Cluster | Direct sun (at least 4-6 hours) | Every 5–7 days; allow top 2–3 cm of soil to dry | Pet-safe |
| 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 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-fleshed Durian | Direct sun (at least 4-6 hours) | Daily watering in dry periods; 3–4 times per week when humidity is high | Pet-safe |
| Red-Topped Sage | Direct sun (at least 4-6 hours) | Water when the top 3 cm of soil feels dry | Pet-safe |
| Reed Avocado | Direct sun (at least 4-6 hours) | Deep watering when the top 5 cm of soil dries, about every 5-7 days in warm growth | 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 |
| Regel's Sage | Direct sun (at least 4-6 hours) | Moderate; approximately 2.5 cm (1 inch) per week | 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 |
| Renny Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in summer | 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 |
| 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 |
| 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 |
| 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 |
| Ringed Sage | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to dry between waterings | Pet-safe |
| Rio Jaboticaba | Direct sun (at least 4-6 hours) | Every 2–3 days when young; deeply once or twice per week when established | Mildly toxic to pets |
| Rise 'n' Shine Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, around every 2-4 days in summer | Pet-safe |
| 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 |
| Robert Chapman heather | Direct sun (at least 4-6 hours) | Regular watering for the first season; drought-tolerant once established | Pet-safe |
| Robert Young Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week when establishing; weekly 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 |
| Roborowsky's Sage | Direct sun (at least 4-6 hours) | Moderate; keep soil evenly moist | 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 Daffodil | Direct sun (at least 4-6 hours) | Minimal; moderate during active growth, completely dry in summer | Toxic to pets |
| Rock Jasmine | Direct sun (at least 4-6 hours) | Water moderately in spring and summer; reduce in autumn and winter | 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 |
| 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 Bee Plant | 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 |
| 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 Douglas Fir | Direct sun (at least 4-6 hours) | Moderate during establishment; drought-tolerant once established | Pet-safe |
| 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 |
| Roesl's Uncarina | Direct sun (at least 4-6 hours) | Every 10–14 days in active growth; none or minimal October–March | Mildly toxic to pets |
| Roller Jovibarba | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer; minimal 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 |
| Rolling Houseleek | Direct sun (at least 4-6 hours) | Low — extremely drought-tolerant | Mildly toxic to pets |
| 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 | Direct sun (at least 4-6 hours) | Deep watering once a week, more in heat | Pet-safe |
| Rose Apple | Direct sun (at least 4-6 hours) | Deep watering every 5-7 days in growth; more often in fruiting and heat | 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 | Direct sun (at least 4-6 hours) | Weekly during dry spells; drought-tolerant once established | Mildly toxic to pets |
| 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 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 Willowherb | Direct sun (at least 4-6 hours) | Minimal once established; tolerates both dry and wet soils | Pet-safe |
| 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 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 |
| 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 Hawkbit | Direct sun (at least 4-6 hours) | Low — requires water only during prolonged summer drought | Pet-safe |
| Rough Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established | Mildly toxic to pets |
| 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 |
| Rounded Sweetgum | Direct sun (at least 4-6 hours) | Weekly during establishment; less once mature | Mildly toxic to pets |
| Roundhead Prairie Clover | Direct sun (at least 4-6 hours) | Once established, water deeply every 2–3 weeks in summer; no supplemental water needed once the taproot is mature | Pet-safe |
| Roundleaf Pickerelweed | Direct sun (at least 4-6 hours) | Permanently aquatic — plant in still or slow-moving water 5–20 cm (2–8 in) deep or in consistently waterlogged marginal soil. | Pet-safe |
| 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 |
| Royal Blue Aubrieta | Direct sun (at least 4-6 hours) | Weekly in spring and autumn; infrequently in summer | Pet-safe |
| 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 |
| Rubenza cosmos | Direct sun (at least 4-6 hours) | Every 5–7 days; drought tolerant once established | Pet-safe |
| 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 |
| Ruellia Brittoniana | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 5-10 days; very drought-tolerant once established | Mildly toxic to pets |
| Rugosa Rose | Direct sun (at least 4-6 hours) | weekly when establishing, monthly once established | Pet-safe |
| 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 Olive | Direct sun (at least 4-6 hours) | Low; highly drought-tolerant | Pet-safe |
| Rustica Rubra magnolia | Direct sun (at least 4-6 hours) | Regularly when young; moderate once established | 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 |
| Rutenberg's Pachypodium | Direct sun (at least 4-6 hours) | Every 7–14 days in summer; once monthly or less in winter | Toxic to pets |
| 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 |
| Sabal Bermudana | 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 |
| Sabal Mexicana | 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 |
| Sabre-Leaved Hottentot Fig | Direct sun (at least 4-6 hours) | very low — water only when soil is dry | Mildly toxic to pets |
| Sacahuista | Direct sun (at least 4-6 hours) | Every 3–4 weeks in summer; monthly or less in winter | Mildly 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 |
| Sacred Buddhist | Direct sun (at least 4-6 hours) | Every 2–4 days in summer (or as soon as the soil surface begins to dry); less frequently in winter | 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 |
| Saguaro Cactus | Direct sun (at least 4-6 hours) | When the soil is bone dry, roughly every 2-3 weeks in summer; none in winter | Mildly toxic to pets |
| Sahuc's Sun Rose Hybrid | Direct sun (at least 4-6 hours) | Infrequent once established | Mildly toxic to pets |
| Sakhalin Fir | Direct sun (at least 4-6 hours) | Moderate; water regularly during establishment | 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 |
| Salvia | Direct sun (at least 4-6 hours) | Weekly watering | Pet-safe |
| Salvia 'Hot Lips' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; weekly while establishing, then infrequently | Pet-safe |
| Salvia 'May Night' | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry; roughly weekly, less once established | Pet-safe |
| Salvia × sylvestris 'Blauhügel' | Direct sun (at least 4-6 hours) | When top 3-5 cm of soil is dry, roughly every 7-10 days once established | Pet-safe |
| Salvia farinacea 'Evolution Violet' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days once established | Pet-safe |
| Salvia farinacea 'Strata' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 4-7 days once established | Pet-safe |
| Salvia nemorosa 'Ostfriesland' | Direct sun (at least 4-6 hours) | When top 3-5 cm of soil is dry, about every 7-10 days once established | Pet-safe |
| Salvia splendens 'Sizzler Burgundy' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days | Mildly toxic to pets |
| Salvia splendens 'Vista Red' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in summer heat | Pet-safe |
| Salvia verticillata 'Purple Rain' | Direct sun (at least 4-6 hours) | When top 3-5 cm of soil is dry, about every 7-10 days once established | Pet-safe |
| Salvia yangii | Direct sun (at least 4-6 hours) | When top 5 cm of soil is dry, roughly every 10-14 days once established | Mildly toxic to pets |
| 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 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 Bluestem | Direct sun (at least 4-6 hours) | Minimal — seasonal rainfall only in most settings | Pet-safe |
| 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 Everlasting | Direct sun (at least 4-6 hours) | Every 2–4 weeks; minimal in winter | Mildly toxic to pets |
| 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 Sedge | Direct sun (at least 4-6 hours) | Very infrequent — drought-adapted | Pet-safe |
| Sander's Vanda | Direct sun (at least 4-6 hours) | Daily in warmth; every 2-3 days when cool and dim | 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 |
| 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 |
| Sanguine Coneflower | Direct sun (at least 4-6 hours) | Weekly during first season; every 3–4 weeks once established | 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 |
| Santa Rita Prickly Pear | Direct sun (at least 4-6 hours) | Sparingly when soil is fully dry, about every 3-4 weeks in summer; nearly none in winter | Pet-safe |
| Santol | Direct sun (at least 4-6 hours) | 2–3 times per week when establishing; established trees tolerate short dry spells | Mildly toxic to pets |
| Sanvitalia procumbens 'Mandarin Orange' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-4 days in summer containers | Pet-safe |
| Sanvitalia procumbens 'Sunvy Yellow' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of compost is dry, roughly every 2-4 days in summer containers | Pet-safe |
| 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 |
| Sapodilla | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-10 days in growth | 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 |
| Sapphire Tower | Direct sun (at least 4-6 hours) | every 7–10 days in the growing season, every 21–28 days in winter | Pet-safe |
| 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 |
| Sarracenia 'Juthatip Soper' | Direct sun (at least 4-6 hours) | Keep permanently wet with the tray method, standing in 1-3 cm of water during the growing season | Pet-safe |
| Sarracenia × catesbaei | Direct sun (at least 4-6 hours) | Keep media constantly wet; stand the pot in 1-2 cm of water during the growing season | Pet-safe |
| Sarracenia × excellens | Direct sun (at least 4-6 hours) | Permanently moist; tray-water in 1-2 cm of pure water through the growing season | Pet-safe |
| Sarracenia flava var. ornata | Direct sun (at least 4-6 hours) | Keep constantly wet, standing in 1-3 cm of water through the growing season | Mildly toxic to pets |
| Sarracenia leucophylla 'Tarnok' | Direct sun (at least 4-6 hours) | Keep constantly wet; stand in 1-2 cm of pure water during the growing season | Pet-safe |
| Sarracenia Minor | Direct sun (at least 4-6 hours) | Keep permanently wet; stand the pot in 1-3 cm of pure water during the growing season | 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 |
| Sarracenia purpurea subsp. venosa | Direct sun (at least 4-6 hours) | Keep permanently moist to standing in 1-3 cm of water; never let the bog dry out | Mildly toxic to pets |
| Sarracenia Rubra | Direct sun (at least 4-6 hours) | Keep the soil constantly wet; stand the pot in 1-3 cm of water during the growing season | Pet-safe |
| Satellit Bosnian Pine | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Mildly toxic to pets |
| 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 |
| Saucer Magnolia | Direct sun (at least 4-6 hours) | Weekly while establishing, then during dry spells | Pet-safe |
| Savanna Gardenia | Direct sun (at least 4-6 hours) | Every 10–14 days during the growing season; every 21–28 days in dry season | Mildly toxic to pets |
| Savin Juniper | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; weekly during the first growing season | 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 |
| Scaevola aemula 'Bombay Dark Blue' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm is dry, roughly every 3-5 days | Mildly toxic to pets |
| Scaevola aemula 'Whirlwind White' | Direct sun (at least 4-6 hours) | Water when the top 2-3 cm dries; baskets often need it every 1-3 days | Mildly toxic to pets |
| Scaly Blazing Star | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought | 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 | Direct sun (at least 4-6 hours) | When the mix is dry, about every 10-14 days in growth; sparingly in winter | Pet-safe |
| Scarlet 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 |
| 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 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 Martagon Lily | Direct sun (at least 4-6 hours) | Moderate — water when top 5 cm of soil is dry | Toxic to pets |
| Scarlet Passion Flower | Direct sun (at least 4-6 hours) | When the top 2 cm of soil is dry, roughly every 5-8 days in summer | Mildly toxic to pets |
| 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 |
| 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 |
| 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 |
| 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 |
| Scrub Palmetto | Direct sun (at least 4-6 hours) | Rarely after establishment — every 3–6 weeks in extended dry spells | Pet-safe |
| Sea Apple | Direct sun (at least 4-6 hours) | Every 10–14 days for established trees; weekly for young or containerised plants | Mildly toxic to pets |
| Sea Bindweed | Direct sun (at least 4-6 hours) | Sparingly; rely on rainfall in a well-drained coastal setting | Mildly toxic to pets |
| Sea Campion | Direct sun (at least 4-6 hours) | Every 1–2 weeks; drought-tolerant once established | Pet-safe |
| Sea Heath | Direct sun (at least 4-6 hours) | Very low; drought-tolerant once established | Mildly toxic to pets |
| Sea Hibiscus | Direct sun (at least 4-6 hours) | 1–2 times per week in spring and summer; reduce in winter | 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 Mouse-ear | Direct sun (at least 4-6 hours) | Minimal; rely on rainfall in outdoor settings | Mildly toxic to pets |
| Sea Pea | Direct sun (at least 4-6 hours) | Infrequently; allow soil to dry between waterings | 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 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 Cactus | Direct sun (at least 4-6 hours) | When the top of the soil is dry, roughly weekly to fortnightly in summer; keep nearly dry in winter | 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 | Direct sun (at least 4-6 hours) | When the soil is dry, every 10-14 days for potted plants | 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 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 hernandezii | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in summer, very sparingly in winter | Pet-safe |
| Sedum palmeri | Direct sun (at least 4-6 hours) | When the soil is dry, about every 10-14 days in summer, 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 |
| 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 |
| Senegal Date Palm | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry, roughly every 5-10 days | Pet-safe |
| 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 |
| Sensation Mix Cosmos | 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 |
| Sensation Mixed cosmos | Direct sun (at least 4-6 hours) | Once or twice weekly until established; then only during prolonged dry spells | Pet-safe |
| Sensation Mixed cosmos | Direct sun (at least 4-6 hours) | Every 5–7 days; very drought tolerant once established | Pet-safe |
| 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 |
| Sesse's Sage | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; monthly in winter | Mildly toxic to pets |
| Sessile Oak | Direct sun (at least 4-6 hours) | Rainfall-dependent once established; water deeply during the first 2–3 years | Mildly toxic to pets |
| Seven-Spined Discocactus | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is completely dry, approximately every 10-14 days in the growing season; once a month or less in winter | Pet-safe |
| Sexy Pink Heliconia | Direct sun (at least 4-6 hours) | 2–3 times per week in summer, reducing in winter | Mildly toxic to pets |
| Sexy Rexy Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | Pet-safe |
| Shadscale Saltbush | Direct sun (at least 4-6 hours) | Every 3–5 weeks during establishment, then rainfall only | 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 |
| 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-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 |
| 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 |
| Shenandoah Switchgrass | Direct sun (at least 4-6 hours) | Weekly during establishment (first season); monthly or as needed once established | Pet-safe |
| Sheridan Spire Dawn Redwood | Direct sun (at least 4-6 hours) | Regularly — maintain consistently moist soil | Pet-safe |
| 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 |
| Shingle Oak | Direct sun (at least 4-6 hours) | Moderate; weekly irrigation for first 2 seasons; drought-tolerant once established | Mildly 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 Mandevilla | Direct sun (at least 4-6 hours) | 2-3 times per week in summer, reduce to every 10-14 days in winter | Mildly toxic to pets |
| Shining Pondweed | Direct sun (at least 4-6 hours) | Fully submerged — permanently aquatic; water is the growing medium, not an irrigation schedule | Pet-safe |
| Shore Juniper | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; regular watering for first 12 months | 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-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-leaved Deuterocohnia | Direct sun (at least 4-6 hours) | Every 2 weeks in summer; monthly or less in winter | Pet-safe |
| Short-Sepalled Lewisia | Direct sun (at least 4-6 hours) | Moderate in spring; bone-dry in summer dormancy | Mildly 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 Goldenrod | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water in extended dry spells only | 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 |
| Showy Tick Trefoil | Direct sun (at least 4-6 hours) | Water weekly to every 10 days during dry spells in the first season; once established, tolerates moderate drought but prefers consistently moist soil | 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 | Direct sun (at least 4-6 hours) | Once a week during establishment; drought-tolerant once established | 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 Iris | Direct sun (at least 4-6 hours) | Regular — keep soil consistently moist | Toxic to pets |
| Siberian Larch | Direct sun (at least 4-6 hours) | Weekly during establishment; low once established | Pet-safe |
| 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 |
| Sibthorp's Everlasting | Direct sun (at least 4-6 hours) | Every 2–3 weeks in growing season; sparingly in winter | Mildly 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 |
| 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 |
| Sidebells Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; monthly in cool or dormant seasons | Mildly toxic to pets |
| Sidebells Penstemon | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; monthly in cool seasons | 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 |
| 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 |
| Signet marigold | Direct sun (at least 4-6 hours) | Once or twice weekly; allow top 2 cm of soil to dry between waterings | Mildly toxic to pets |
| Signet Marigold 'Lemon Gem' | Direct sun (at least 4-6 hours) | When top 2-3 cm of soil is dry, every 4-7 days; containers more often | Mildly toxic to pets |
| 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 |
| Silberlocke Korean Fir | Direct sun (at least 4-6 hours) | Regularly; maintain consistently moist soil | 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 Lupine | Direct sun (at least 4-6 hours) | Low; deeply water every 2–3 weeks during the growing season; minimal water once dormant | Toxic to pets |
| Silky Prairie Clover | Direct sun (at least 4-6 hours) | Very low — highly drought-tolerant; avoid overwatering | Mildly toxic to pets |
| silky thread grass | Direct sun (at least 4-6 hours) | Once established, water only during extended drought; every 2–3 weeks in hot, dry summers | Pet-safe |
| Silky wisteria | Direct sun (at least 4-6 hours) | Weekly during growing season; reduce in winter | Toxic to pets |
| 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 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 Knight heather | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate watering once established | Pet-safe |
| Silver Mediterranean Fan Palm | Direct sun (at least 4-6 hours) | Moderate; allow top 3–5 cm to dry between waterings | Pet-safe |
| Silver Mound Artemisia | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly every 7-10 days while establishing, then rarely | Toxic to pets |
| Silver Mullein | Direct sun (at least 4-6 hours) | Every 2–4 weeks when established; weekly for young transplants | 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 Ragwort | Direct sun (at least 4-6 hours) | low — allow soil to dry between waterings | 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 Staghorn Fern | Direct sun (at least 4-6 hours) | When the mount is thoroughly dry, soak every 10-21 days; allows longer dry periods than most staghorns | Pet-safe |
| 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 Tibouchina | Direct sun (at least 4-6 hours) | Water regularly during the growing season to keep the soil moist but not waterlogged; reduce in winter. | 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 |
| Silverberry | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| Silverbush | Direct sun (at least 4-6 hours) | Moderate in the growing season, minimal in winter | Mildly toxic to pets |
| Silvery Lupine | Direct sun (at least 4-6 hours) | Low to moderate; water deeply every 2–3 weeks during the growing season; drought-tolerant once established | Toxic to pets |
| 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 |
| 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 |
| Singapore Plumeria | Direct sun (at least 4-6 hours) | Every 7–14 days in the growing season; very sparingly in winter | Toxic to pets |
| Singapore Yellow Frangipani | Direct sun (at least 4-6 hours) | Weekly to fortnightly during active growth; very sparingly in winter dormancy | 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 |
| sioux blue indian grass | Direct sun (at least 4-6 hours) | Regularly during first season; once established, water only during prolonged summer drought | Pet-safe |
| 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 |
| Sitka Spruce | Direct sun (at least 4-6 hours) | Regular — keep soil consistently moist; very high natural rainfall in native habitat | Pet-safe |
| Six Hills Giant Catmint | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; about every 7-10 days while establishing, then seldom | 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 Flower Vine | Direct sun (at least 4-6 hours) | When the top 3 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Sky Lupine | Direct sun (at least 4-6 hours) | Low; winter rainfall sufficient in most California climates; light supplemental water in February–March extends bloom | Toxic to pets |
| Sky Rocket Feather Top | Direct sun (at least 4-6 hours) | Weekly while establishing, then occasional deep watering in drought | Pet-safe |
| Skyracer Moor Grass | Direct sun (at least 4-6 hours) | Regular; maintain consistent moisture | 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 |
| Slender Aubrieta | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Mildly toxic to pets |
| Slender Iceplant | Direct sun (at least 4-6 hours) | Sparingly; allow soil to dry completely between waterings | Pet-safe |
| Slender Silhouette Sweetgum | Direct sun (at least 4-6 hours) | Weekly during the first 2–3 years; supplemental in drought once established | Mildly toxic to pets |
| 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 |
| 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 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 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 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-scaled Pink | Direct sun (at least 4-6 hours) | Low to moderate; allow soil to approach dryness between waterings | 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 Cayenne Pineapple | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| Smooth Coneflower | Direct sun (at least 4-6 hours) | Weekly during establishment; every 2–3 weeks once established | Pet-safe |
| Smooth Cordgrass | Direct sun (at least 4-6 hours) | Continuous tidal immersion — lower intertidal zone | Pet-safe |
| Smooth Oxeye | Direct sun (at least 4-6 hours) | Every 1-2 weeks | Pet-safe |
| 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 |
| 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 | Direct sun (at least 4-6 hours) | Keep consistently moist; water every 4-7 days, more in heat | Toxic to pets |
| 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 Banana | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil begins to dry, roughly every 5-7 days in summer | Pet-safe |
| 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-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 |
| Snowcap Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks in summer; keep dry in winter | Pet-safe |
| Soap Aloe | Direct sun (at least 4-6 hours) | When soil is fully dry, every 1-2 weeks in warm growth | Toxic to pets |
| Soft Draba | Direct sun (at least 4-6 hours) | Very low — keep almost dry in winter | Mildly toxic to pets |
| 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 |
| Somali Desert Rose | Direct sun (at least 4-6 hours) | Weekly in hot active growth (above 30°C/86°F); cease or minimise in winter | Toxic to pets |
| Soncoya | Direct sun (at least 4-6 hours) | Twice weekly when young; weekly once established | 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 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 |
| Sophy's Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in growth; container plants checked more often | Pet-safe |
| 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 |
| Soursop | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top 2-3 cm of soil dries | 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 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 |
| 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 Draba | Direct sun (at least 4-6 hours) | Water sparingly; allow soil to dry between waterings | Pet-safe |
| 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 Houseleek | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; once a month in winter | 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 snapdragon | Direct sun (at least 4-6 hours) | Once established, every 7–14 days in summer; rarely in winter | Mildly toxic to pets |
| Spanish Stonecrop | Direct sun (at least 4-6 hours) | Low — drought-tolerant; water only in very dry spells | Pet-safe |
| Sparganium erectum | Direct sun (at least 4-6 hours) | Constantly wet; shallow water or saturated margin | 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 |
| 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 Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth; none in winter | 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 |
| Spike heath | Direct sun (at least 4-6 hours) | Low to moderate — once established, water only during prolonged drought | 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 |
| Spiny Adenia | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; completely dry in winter | Toxic to pets |
| 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 Orostachys | Direct sun (at least 4-6 hours) | Every 2–3 weeks in the growing season; almost none in winter dormancy | 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 |
| 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 |
| Split Rock | Direct sun (at least 4-6 hours) | Soak-and-dry, only when fully dry — roughly every 2-3 weeks in active growth; little to none in summer and 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 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 |
| Spottted Horsemint | Direct sun (at least 4-6 hours) | Water to establish, then only in prolonged drought, roughly every 10-14 days | Mildly toxic to pets |
| Spreading Bellflower | Direct sun (at least 4-6 hours) | Low — water only during prolonged dry spells | 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 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 |
| 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-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 |
| Standish's Golden Yew | Direct sun (at least 4-6 hours) | Moderate — once established, rarely needs irrigation in UK climates | Toxic to pets |
| Star Apple | Direct sun (at least 4-6 hours) | When the top few centimetres of soil dry out, around every 4-7 days in active growth | Mildly toxic to pets |
| Star Cactus | Direct sun (at least 4-6 hours) | Every 2-4 weeks in spring/summer; roughly monthly or less in winter | 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 | Direct sun (at least 4-6 hours) | Infrequent; relies on natural rainfall in most temperate gardens | Toxic to pets |
| Star-fruited Uncarina | Direct sun (at least 4-6 hours) | Every 10–14 days in growing season; completely dry during winter dormancy | Mildly toxic to pets |
| Stardust Ice Plant | Direct sun (at least 4-6 hours) | Every 1–2 weeks during active growth; very sparingly in winter | Pet-safe |
| 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 |
| Starfruit | Direct sun (at least 4-6 hours) | Every 3-7 days, keeping soil consistently moist; carambola is not drought-tolerant | Toxic to pets |
| Starina Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 2-4 days in summer | Pet-safe |
| Starry Rosinweed | Direct sun (at least 4-6 hours) | Low — drought-tolerant once established | Mildly toxic to pets |
| Statice | Direct sun (at least 4-6 hours) | Low to moderate — allow soil to dry between waterings | Pet-safe |
| 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 Thistle | Direct sun (at least 4-6 hours) | Very low — fully drought tolerant | Mildly toxic to pets |
| Stenocactus crispatus | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 10-14 days in growth; keep dry in winter | Pet-safe |
| 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 |
| Steppe Sage | Direct sun (at least 4-6 hours) | Low — every 10–14 days in summer, minimal in winter | Mildly toxic to pets |
| Sterling Silver Linden | Direct sun (at least 4-6 hours) | Weekly during the first 2 years; monthly deep watering once established | 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 |
| 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 |
| Stock | Direct sun (at least 4-6 hours) | Every 5–7 days; keep evenly moist but not wet | Pet-safe |
| 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 |
| Stoneham Gold Western Red Cedar | Direct sun (at least 4-6 hours) | Weekly when young; less once established | Mildly toxic to pets |
| 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-red Sage | Direct sun (at least 4-6 hours) | Every 10–14 days once established; weekly for new plants | 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 Fields gomphrena | Direct sun (at least 4-6 hours) | Weekly; drought-tolerant once established | Pet-safe |
| Strawberry globe amaranth | Direct sun (at least 4-6 hours) | Every 7–14 days once established; moderate during establishment | Pet-safe |
| Strawberry Guava | Direct sun (at least 4-6 hours) | Every 5-10 days, keeping soil evenly moist while fruiting; tolerates short dry spells once established | Mildly toxic to pets |
| Strawflower | Direct sun (at least 4-6 hours) | Every 7–10 days; very drought-tolerant | Mildly 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 of Buttons | Direct sun (at least 4-6 hours) | Every 1-2 weeks in growing season; roughly monthly in winter | Mildly toxic to pets |
| String of pearls | Direct sun (at least 4-6 hours) | When the soil is completely dry, every 2-3 weeks | Toxic to pets |
| String of pickles | Direct sun (at least 4-6 hours) | When the soil is fully dry, roughly every 2-3 weeks | Mildly toxic to pets |
| 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 |
| Subalpine Fir | Direct sun (at least 4-6 hours) | Regular watering during establishment; naturally sustained by snowmelt and high-altitude precipitation | Pet-safe |
| Subalpine Larch | Direct sun (at least 4-6 hours) | Moderate; supplemental irrigation during dry summers | Pet-safe |
| Succulentum Pachypodium | Direct sun (at least 4-6 hours) | Every 1–2 weeks in summer; withhold in winter | Toxic to pets |
| Sugar Apple | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm dries; tolerates drying between waterings | 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 |
| Sugarloaf Pineapple | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days | Pet-safe |
| 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 |
| Sullivant's Milkweed | Direct sun (at least 4-6 hours) | Regular; maintain consistent moisture | Toxic to pets |
| Sulphur Cosmos | Direct sun (at least 4-6 hours) | Water until established, then only in extended drought; highly drought-tolerant | 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 |
| Summer Hyacinth | Direct sun (at least 4-6 hours) | Regular during spring and summer; reduce in autumn and winter | Pet-safe |
| Summer Impala Lily | Direct sun (at least 4-6 hours) | Every 7–14 days in active growth; sparingly or not at all in winter dormancy | Toxic to pets |
| 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 |
| 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 Flare Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | Pet-safe |
| Sunblaze Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, about every 2-4 days in summer | Pet-safe |
| Sunflower | Direct sun (at least 4-6 hours) | Deep watering once a week | 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 |
| Sunningdale Silver Pampas Grass | Direct sun (at least 4-6 hours) | Weekly while establishing; thereafter only in extended drought | Pet-safe |
| Sunrise Crown Cactus | Direct sun (at least 4-6 hours) | When fully dry, roughly every 12-16 days in growth; none in winter | Pet-safe |
| 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 |
| Sunset Hyssop | Direct sun (at least 4-6 hours) | Every 7–10 days once established | Pet-safe |
| Super Kabuto Star Cactus | Direct sun (at least 4-6 hours) | When the soil is fully dry, about every 10-14 days in growth; none in winter | Pet-safe |
| Super King Ixora | Direct sun (at least 4-6 hours) | Every 2-3 days in active growing season, weekly in winter | Mildly toxic to pets |
| Super King Ixora Red | Direct sun (at least 4-6 hours) | Every 5–7 days; maintain consistent moisture without waterlogging | 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 |
| 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 |
| Supertunia 'Vista Bubblegum' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry; daily in hot weather and containers | Pet-safe |
| Supertunia bubblegum petunia | Direct sun (at least 4-6 hours) | Every 2–4 days in containers in heat; every 5–7 days in borders | Pet-safe |
| Surinam Cherry | Direct sun (at least 4-6 hours) | When the top 4-5 cm of soil dries, roughly weekly; less once established | 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 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) | Frequently; keep soil moist, tolerates wet conditions | Mildly 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 Sunflower | Direct sun (at least 4-6 hours) | Consistently moist; water weekly or more in dry periods | Pet-safe |
| Swamp Tupelo | Direct sun (at least 4-6 hours) | Constantly moist to permanently flooded | Mildly toxic to pets |
| 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 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 Black-Eyed Susan | Direct sun (at least 4-6 hours) | Weekly in the first growing season; every 10–14 days when established | Pet-safe |
| Sweet Chariot Miniature Rose | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, often every 1-3 days in baskets during summer | Pet-safe |
| Sweet Clockvine | Direct sun (at least 4-6 hours) | Every 5–7 days; allow the top soil to partially dry between waterings | Mildly toxic to pets |
| Sweet Granadilla | Direct sun (at least 4-6 hours) | Every 4-7 days, keeping soil evenly moist during growth and fruiting; avoid both drought and waterlogging | 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 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 |
| Sweetbriar Rose | Direct sun (at least 4-6 hours) | Weekly while establishing, then minimal | Pet-safe |
| Swiss Rock Jasmine | Direct sun (at least 4-6 hours) | Very sparingly year-round; almost dry in winter | Pet-safe |
| Sword-Leaved Phlox | Direct sun (at least 4-6 hours) | Weekly until established; monthly or less once established in well-drained soil | 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 |
| Syagrus Romanzoffiana | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 5-10 days in heat | Pet-safe |
| Sycamore Maple | Direct sun (at least 4-6 hours) | Drought-tolerant once established; water young trees weekly for the first 2 years | Toxic to pets |
| 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 |
| Tagetes erecta 'Inca Gold' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-4 days | Pet-safe |
| Tagetes erecta 'Taishan Orange' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-4 days | Pet-safe |
| Tagetes patula 'Boy Orange' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days | Pet-safe |
| Tagetes patula 'Janie Bright Yellow' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 3-5 days | Pet-safe |
| Tagetes tenuifolia 'Tangerine Gem' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 5-7 days | Pet-safe |
| Tahitian Gardenia | Direct sun (at least 4-6 hours) | Every 5–7 days when in active growth; every 10–14 days in cooler months | Mildly toxic to pets |
| 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 Green Milkweed | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Toxic to pets |
| 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 |
| Tall Verbena | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-14 days once established | Mildly toxic to pets |
| Tamanu | Direct sun (at least 4-6 hours) | Weekly when established; more frequent for young trees | Mildly toxic to pets |
| 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 |
| Tamarind | Direct sun (at least 4-6 hours) | Water moderately; let the top few cm of soil dry between waterings, roughly weekly | Toxic to pets |
| Tamarix-leaf Savin Juniper | Direct sun (at least 4-6 hours) | Low — very drought-tolerant once established | 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 |
| 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 |
| 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 |
| Teasing Georgia Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season; more in heat | Pet-safe |
| Teddy Bear Palm | Direct sun (at least 4-6 hours) | Every 3–5 days when established in ground; check containers daily in summer | Pet-safe |
| Teddy Bear Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil dries out, roughly every 7-14 days depending on conditions | Pet-safe |
| Teddy Bear sunflower | Direct sun (at least 4-6 hours) | Weekly, or every 5–7 days during dry spells | Pet-safe |
| 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 |
| Tennessee Coneflower | Direct sun (at least 4-6 hours) | Water to establish, then only during extended drought | 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 |
| Terap | Direct sun (at least 4-6 hours) | Every 3–5 days when young; established trees every 7–10 days | 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 |
| Tessellated Vanda | Direct sun (at least 4-6 hours) | Daily in heat; every 2-3 days in cool, low-light spells | Pet-safe |
| Tete Cycad | Direct sun (at least 4-6 hours) | Every 2–4 weeks in the growing season; once a month or less in winter | 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 Blazing Star | Direct sun (at least 4-6 hours) | Every 2–3 weeks during establishment; minimal once established | Pet-safe |
| Texas Bluebonnet | Direct sun (at least 4-6 hours) | Low; rely on rainfall; supplement only during prolonged dry spells in winter/spring | Toxic to pets |
| Texas Bluebonnet Subsp. | Direct sun (at least 4-6 hours) | Low; relies on autumn and winter rainfall; no regular supplemental watering needed once established | Toxic to pets |
| 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 Sacahuista | Direct sun (at least 4-6 hours) | Every 3–4 weeks in the growing season; monthly or less in winter | Mildly toxic to pets |
| Texas Sage | Direct sun (at least 4-6 hours) | Moderate — water once or twice weekly in the growing season | 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 flavum subsp. glaucum | Direct sun (at least 4-6 hours) | Keep soil moist; water deeply in dry weather | Mildly toxic to pets |
| Thatch Palm | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-12 days, less in cool weather | Mildly toxic to pets |
| The Blues Little Bluestem | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the first growing season; minimal once established | Pet-safe |
| The Blues Little Bluestem | Direct sun (at least 4-6 hours) | Weekly for first season; every 3–4 weeks or rain-fed once established | Pet-safe |
| 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 Dark Lady Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | 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 |
| Thelocactus bicolor | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 12-16 days in summer; none in winter | Pet-safe |
| Thelocactus hexaedrophorus | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 12-16 days in summer; none in winter | Pet-safe |
| Thelocactus setispinus | Direct sun (at least 4-6 hours) | When the top of the mix dries, roughly every 7-12 days in growth; keep dry in winter | Pet-safe |
| 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 |
| Thessalian Aubrieta | Direct sun (at least 4-6 hours) | Low — water sparingly once established | Mildly toxic to pets |
| Thick-footed Operculicarya | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; withheld in winter dormancy | 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 |
| 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 Adenia | Direct sun (at least 4-6 hours) | Every 2–4 weeks in summer growing season; none in winter dormancy | Toxic to pets |
| Thorny Bamboo | Direct sun (at least 4-6 hours) | 2-3 times per week during establishment and growing season; drought-tolerant once established | Pet-safe |
| Thoroughwax | Direct sun (at least 4-6 hours) | Every 5–7 days; allow top inch to partially dry between waterings | Pet-safe |
| Thouars Cycad | Direct sun (at least 4-6 hours) | Every 10–14 days in the growing season; every 3–4 weeks in winter | Toxic to pets |
| 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-Coloured Vanda | Direct sun (at least 4-6 hours) | Daily in warm growth; every 2-3 days when cool and dim | Pet-safe |
| Three-leaved Lantana | Direct sun (at least 4-6 hours) | Every 1–2 weeks | 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 |
| Three-lobed Coneflower | Direct sun (at least 4-6 hours) | When the top 3–4 cm of soil is dry; roughly weekly in the growing season, more during drought | Mildly toxic to pets |
| Three-yoked Sage | Direct sun (at least 4-6 hours) | Low — every 10–14 days during active growth; minimal 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 |
| Throatwort | Direct sun (at least 4-6 hours) | Every 4–6 days; water when the top 2 cm of soil begins to dry | Pet-safe |
| Thunberg Spirea | Direct sun (at least 4-6 hours) | Weekly until established; occasional deep watering thereafter | Pet-safe |
| Thunberg's Cycad | Direct sun (at least 4-6 hours) | Every 14–21 days; drought-tolerant once established | Toxic to pets |
| Thunbergia battiscombei | Direct sun (at least 4-6 hours) | When the top few cm of soil dry out, about every 5-7 days in summer | Mildly toxic to pets |
| Thunbergia erecta | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days in growth | Mildly toxic to pets |
| Thyme-Leaved Edraianthus | Direct sun (at least 4-6 hours) | Low — allow soil to dry between waterings | Mildly toxic to pets |
| Thyme-leaved Sandwort | Direct sun (at least 4-6 hours) | Low; water sparingly, allow soil to dry between waterings | Mildly toxic to pets |
| Tian Shan Everlasting | Direct sun (at least 4-6 hours) | Every 2–3 weeks; less in winter | Mildly toxic to pets |
| Tibetan whitebeam | Direct sun (at least 4-6 hours) | Weekly during establishment; low once mature | Mildly toxic to pets |
| Tidal Wave silver petunia | Direct sun (at least 4-6 hours) | Every 3–5 days in containers; every 7–10 days in garden beds | Pet-safe |
| 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 |
| 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 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 |
| 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 |
| Toad Tree | Direct sun (at least 4-6 hours) | Moderate; water regularly in summer, reduce significantly in winter dormancy | Toxic to pets |
| Toe toe | Direct sun (at least 4-6 hours) | Once or twice a week during establishment; monthly once established | Pet-safe |
| 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 |
| Tom Thumb Cactus | Direct sun (at least 4-6 hours) | When the top of the soil is dry, about every 7-10 days in summer; minimal in winter | Pet-safe |
| 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 |
| Tommy Atkins Mango | Direct sun (at least 4-6 hours) | Water when the top 3-5 cm of soil dries in growth; withhold before flowering | Mildly 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 |
| 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 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 |
| Top-shaped Living Stones | Direct sun (at least 4-6 hours) | Every 3–4 weeks in autumn; none in summer or winter | Pet-safe |
| Topeka Purple Coneflower | Direct sun (at least 4-6 hours) | Weekly during establishment; rainfall-dependent once mature (every 3–4 weeks in dry spells) | 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 |
| Torch Mexican sunflower | Direct sun (at least 4-6 hours) | Weekly until established; every 10–14 days once mature; drought-tolerant | Mildly toxic to pets |
| Totara | Direct sun (at least 4-6 hours) | When the topsoil dries, weekly while establishing then as needed | Toxic to pets |
| Totem Pole Cactus | Direct sun (at least 4-6 hours) | When the mix is fully dry, roughly every 2-3 weeks in summer; keep dry in winter | Mildly toxic to pets |
| Touch of Class Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during growth | Pet-safe |
| 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 |
| Trachycarpus Takil | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in summer; reduce sharply over winter | Pet-safe |
| 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 Azalea | Direct sun (at least 4-6 hours) | Moderate; water during dry spells in the growing season but ensure rapid drainage. | Toxic to pets |
| Trailing globe amaranth | Direct sun (at least 4-6 hours) | Every 5–7 days; quite drought-tolerant | 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 |
| Transparent Moor Grass | Direct sun (at least 4-6 hours) | Every 7-14 days; keep moderately moist | Pet-safe |
| Transylvanian Pink | Direct sun (at least 4-6 hours) | Infrequent; allow soil to dry well between waterings | Mildly toxic to pets |
| Traveller's Palm | Direct sun (at least 4-6 hours) | Consistently moist during spring and summer; reduced in winter | Pet-safe |
| Treasure flower | Direct sun (at least 4-6 hours) | Every 10–14 days once established; weekly when young | Mildly toxic to pets |
| Tree Dahlia | Direct sun (at least 4-6 hours) | 2-3 times per week during active growth in summer; deeply, to encourage a strong root system | Mildly toxic to pets |
| 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-Like Pilosocereus | Direct sun (at least 4-6 hours) | When soil is dry to mid-depth, roughly every 10-14 days in summer; monthly in winter | Pet-safe |
| 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 |
| 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 |
| Tropaeolum majus 'Jewel of Africa' | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 4-7 days; containers more often in heat | Pet-safe |
| Tropical Almond | Direct sun (at least 4-6 hours) | Keep evenly moist; water when the top few cm dry, roughly every 5-7 days in heat | Mildly toxic to pets |
| Tropical Dewy Pine | Direct sun (at least 4-6 hours) | Keep medium wet to moist at all times; tray method with 1–2 cm water | 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 |
| Trumpeter Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly | Pet-safe |
| Tube Beardtongue | Direct sun (at least 4-6 hours) | Low to moderate; drought-tolerant once established | Mildly toxic to pets |
| Tuberous Catmint | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; minimal watering in winter dormancy | Pet-safe |
| Tuberous Cranesbill | Direct sun (at least 4-6 hours) | Sparingly in summer; moderate in spring growing season | Mildly toxic to pets |
| Tufted Fescue | Direct sun (at least 4-6 hours) | Every 10–14 days when established; more frequently for newly planted specimens | 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 'Angelique' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; dry off as foliage yellows | Toxic to pets |
| Tulipa 'Apeldoorn' | Direct sun (at least 4-6 hours) | Keep soil moist in growth; dry while dormant | Toxic to pets |
| Tulipa 'Ballerina' | Direct sun (at least 4-6 hours) | Moist through autumn rooting and spring growth; dry off as foliage yellows | Toxic to pets |
| Tulipa 'Black Parrot' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; withhold as foliage dies back | Toxic to pets |
| Tulipa 'Estella Rijnveld' | Direct sun (at least 4-6 hours) | Keep soil evenly moist during autumn rooting and spring growth; let it dry between waterings once foliage yellows | Toxic to pets |
| Tulipa 'Flaming Parrot' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; dry off as foliage yellows | Toxic to pets |
| Tulipa 'Ice Cream' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; dry off as foliage yellows | 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 'Monsella' | Direct sun (at least 4-6 hours) | Moist in active spring growth; dry through summer dormancy | Toxic to pets |
| Tulipa 'Prinses Irene' | Direct sun (at least 4-6 hours) | Keep soil moist while growing in spring; let bulbs stay dry in summer dormancy | Toxic to pets |
| Tulipa 'Purissima' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; dry off as foliage yellows | 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 'Rococo' | Direct sun (at least 4-6 hours) | Moist during autumn rooting and spring growth; dry off as foliage yellows | 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 |
| 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 |
| 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 Pink Sage | Direct sun (at least 4-6 hours) | Every 10–14 days in summer; minimal in winter | 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 |
| 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 |
| Twinspur | Direct sun (at least 4-6 hours) | 2–3 times per week during active growth; reduce during cooler periods | Pet-safe |
| 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 |
| 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-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-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-Row Stonecrop | Direct sun (at least 4-6 hours) | Every 10-14 days until established; essentially rain-fed once rooted | 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 |
| Typhonodorum lindleyanum | Direct sun (at least 4-6 hours) | Permanently submerged or saturated; never let it dry | 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 |
| Umbel Sun Rose | Direct sun (at least 4-6 hours) | Very low — minimal irrigation needed; drought-tolerant once established | Mildly toxic to pets |
| 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 |
| Upright European Hornbeam | Direct sun (at least 4-6 hours) | Moderate; water regularly for first 2–3 seasons; rainfall-dependent once established | Pet-safe |
| Upright Prairie Coneflower | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; very drought-tolerant | Pet-safe |
| Uproar Rose zinnia | Direct sun (at least 4-6 hours) | Regular; deep watering 2–3 times per week at soil level | Pet-safe |
| Urmia Tulip | Direct sun (at least 4-6 hours) | Moderate in spring; dry in summer | Toxic to pets |
| Utricularia subulata | Direct sun (at least 4-6 hours) | Keep constantly wet to waterlogged; stand in 1-2 cm of water at all times | Mildly toxic to pets |
| Uvaia | Direct sun (at least 4-6 hours) | Weekly; keep consistently moist during establishment, more drought-tolerant once mature | Pet-safe |
| Valais fescue | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; more frequent only during establishment | Pet-safe |
| Valentine's Crown Vetch | Direct sun (at least 4-6 hours) | Low to moderate — once every 2–3 weeks when established | Toxic to pets |
| Vanda 'Fuchs Delight' | Direct sun (at least 4-6 hours) | Daily in warm growth; every 2-3 days when cool or low-light | Pet-safe |
| Vanda 'Miss Joaquim' | Direct sun (at least 4-6 hours) | Daily in warm, bright conditions; every 2-3 days if cooler | Pet-safe |
| Vanda 'Robert's Delight' | Direct sun (at least 4-6 hours) | Daily in warm growth; every 2-3 days in cool or dormant spells | Pet-safe |
| Vanda Orchid | Direct sun (at least 4-6 hours) | Daily in warm months; 2-3x weekly in winter | 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 |
| 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 |
| 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 Giant Reed | Direct sun (at least 4-6 hours) | Frequently; keep consistently moist | Mildly 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 silver grass | Direct sun (at least 4-6 hours) | Weekly during the growing season; reduce in autumn and winter | Pet-safe |
| Veitch Fir | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Pet-safe |
| Veitchia Arecina | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 5-9 days in heat | 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 bean | Direct sun (at least 4-6 hours) | Water regularly to keep soil moist, roughly every 4–7 days; tolerates brief dry spells once established | Mildly toxic to pets |
| Velvet Queen sunflower | Direct sun (at least 4-6 hours) | Weekly, more often in hot dry spells | Pet-safe |
| Velvet Tamarind | Direct sun (at least 4-6 hours) | When the top 2-4 cm of soil is dry, roughly every 4-7 days in growth | Mildly toxic to pets |
| Venus Flytrap | Direct sun (at least 4-6 hours) | Keep the medium permanently wet — stand the pot in 1-2 cm of rain or distilled water and top up so it never dries | 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 |
| Verbena × hybrida 'Obsession Coral Eye' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, roughly every 3-5 days in summer | Mildly toxic to pets |
| Verbena × hybrida 'Superbena Stormburst' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 2-4 days in summer | Mildly toxic to pets |
| 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 |
| Veterans' Honor Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly during growth | Pet-safe |
| Victoria amazonica | Direct sun (at least 4-6 hours) | Permanently submerged in warm, still water 0.5-1 m+ deep | Mildly toxic to pets |
| Victoria cruziana | Direct sun (at least 4-6 hours) | Permanently submerged in warm, still water 0.5-1 m+ deep | Mildly toxic to pets |
| 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'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 petunia | Direct sun (at least 4-6 hours) | Every 7–10 days in borders; containers may need more frequent watering | 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 |
| Viper's Bugloss | Direct sun (at least 4-6 hours) | Infrequent once established; drought-tolerant | Mildly toxic to pets |
| 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 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 |
| 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 |
| 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 |
| Waldensian Saxifrage | Direct sun (at least 4-6 hours) | Very low — allow soil to dry between waterings; withhold almost entirely in winter | Pet-safe |
| Walker's Low Catmint | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry; roughly every 7-10 days while establishing, then rarely | Mildly toxic to pets |
| Walker's Low Catmint | Direct sun (at least 4-6 hours) | Every 7–14 days once established | Pet-safe |
| Wallis Fescue | Direct sun (at least 4-6 hours) | Every 14–21 days when established; minimal in winter | Pet-safe |
| Wampee | Direct sun (at least 4-6 hours) | Water deeply every 5-10 days; keep evenly moist when fruiting | Mildly toxic to pets |
| 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 |
| Water Apple | Direct sun (at least 4-6 hours) | 2–3 times per week; keep consistently moist | Mildly toxic to pets |
| Water Canna | Direct sun (at least 4-6 hours) | Aquatic marginal — roots in 0-30 cm of standing water | Mildly toxic to pets |
| Water Hedge | Direct sun (at least 4-6 hours) | Fully submerged; 25-30% water change weekly | Mildly toxic to pets |
| Water Horsetail | Direct sun (at least 4-6 hours) | Submerged or saturated | Mildly toxic to pets |
| 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 |
| Waterberg Cycad | Direct sun (at least 4-6 hours) | Every 3–5 weeks | 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 |
| Waterwheel Plant | Direct sun (at least 4-6 hours) | Fully submerged aquatic — water IS the growing medium | Pet-safe |
| Wave Petunia | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, often daily in baskets and hot weather | Pet-safe |
| Wave purple petunia | Direct sun (at least 4-6 hours) | Every 3–5 days in containers; every 7–10 days in borders | Pet-safe |
| 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 |
| Wavyleaf Coneflower | Direct sun (at least 4-6 hours) | Weekly during establishment (first season); monthly or rainfall-dependent once mature | Pet-safe |
| Wax Jambu | Direct sun (at least 4-6 hours) | Regular deep watering every 4-7 days; more during fruiting and dry heat | Mildly toxic to pets |
| wayfaring tree | Direct sun (at least 4-6 hours) | Weekly when young; rarely needed once established | Mildly 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 |
| 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 European Larch | Direct sun (at least 4-6 hours) | Weekly during establishment; less once established | Pet-safe |
| 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 Love Grass | Direct sun (at least 4-6 hours) | Every 3–4 weeks once established; weekly during establishment | Pet-safe |
| 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 '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 '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 |
| Welwitsch's Thrift | Direct sun (at least 4-6 hours) | Every 2–3 weeks; minimal in winter | Mildly toxic to pets |
| 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 Texas Sage | Direct sun (at least 4-6 hours) | Low; drought-tolerant once established | Pet-safe |
| 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 Ironweed | Direct sun (at least 4-6 hours) | Low to moderate — drought-tolerant once established | Mildly toxic to pets |
| Western Larch | Direct sun (at least 4-6 hours) | Weekly during establishment; thereafter relies on natural precipitation | Pet-safe |
| Western Red Cedar | Direct sun (at least 4-6 hours) | Regular — water deeply once or twice a week until established; drought-sensitive | Pet-safe |
| 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 Sunflower | Direct sun (at least 4-6 hours) | Every 2–4 weeks once established; extremely drought-tolerant | Pet-safe |
| Wheat cockscomb | Direct sun (at least 4-6 hours) | Every 5–7 days in active growth; reduce in cooler periods | Pet-safe |
| 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 |
| 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 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 Ash | Direct sun (at least 4-6 hours) | Moderate; water weekly when young; moderate drought tolerance once established | Mildly toxic to pets |
| White Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; minimal in winter | Pet-safe |
| White Brodiaea | Direct sun (at least 4-6 hours) | Regular during active growth; dry during summer dormancy | Mildly toxic to pets |
| White dipladenia | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; reduce to every 10–14 days in winter. | 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 Frangipani | Direct sun (at least 4-6 hours) | Every 7–14 days in the growing season; once per month or less in winter | 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 Grand Lotus | Direct sun (at least 4-6 hours) | Aquatic — permanently in still or slow-moving water | Mildly toxic to pets |
| White Ixora | Direct sun (at least 4-6 hours) | 2-3 times per week in summer, weekly in winter | 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 Lotus Lily | Direct sun (at least 4-6 hours) | Fully aquatic; roots submerged, leaves floating or emergent | Mildly toxic to pets |
| 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 mountain heather | Direct sun (at least 4-6 hours) | Consistently moist during the growing season; reduce in winter | Pet-safe |
| White Mussaenda | Direct sun (at least 4-6 hours) | Every 2–3 days during active growth; reduce in cooler months | 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) | Regular moisture with periodic dry spells | 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 Spruce | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; regular watering for first 2 years | 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 Trumpet Pitcher | Direct sun (at least 4-6 hours) | Keep constantly wet via the tray method, standing in 1-3 cm of water through the growing season | Pet-safe |
| 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-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-flowered Beardtongue | Direct sun (at least 4-6 hours) | Every 2–3 weeks once established; minimal in winter | 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-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-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 |
| Whitley's Speedwell | Direct sun (at least 4-6 hours) | Every 10–14 days during active growth; minimal in winter | Pet-safe |
| Whorled Heath | Direct sun (at least 4-6 hours) | Infrequent once established; drought-tolerant | Mildly toxic to pets |
| Whorled Milkweed | Direct sun (at least 4-6 hours) | Water to establish, then rarely; highly drought-tolerant once settled | 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-Bract Heliconia | Direct sun (at least 4-6 hours) | Regularly during growing season; withhold water for 4–6 weeks in autumn/winter to trigger flowering | Mildly toxic to pets |
| Wide-Leaved Sea Lavender | Direct sun (at least 4-6 hours) | Every 2–3 weeks when established | Pet-safe |
| 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 Custard Apple | Direct sun (at least 4-6 hours) | Weekly during the growing season; monthly during dry dormancy | Mildly toxic to pets |
| Wild Edric Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly in the growing season, more in heat or sandy soil | Pet-safe |
| Wild Garlic Vine | Direct sun (at least 4-6 hours) | Every 5–7 days during the growing season; reduce in cooler months | Mildly 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 Lupine | Direct sun (at least 4-6 hours) | Water to establish, then rarely; it is drought-tolerant once settled | Toxic to pets |
| Wild maracuja | Direct sun (at least 4-6 hours) | Every 7–14 days; drought-tolerant once established | Mildly 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 Pineapple | Direct sun (at least 4-6 hours) | Every 7–14 days; very drought-tolerant once established | Mildly toxic to pets |
| 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 Star Apple | Direct sun (at least 4-6 hours) | Every 7–10 days when young; drought-tolerant once established | Mildly toxic to pets |
| 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 |
| Wildeve Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly while growing, increasing in heat and on free-draining soils | Pet-safe |
| Wildfire Black Tupelo | Direct sun (at least 4-6 hours) | Weekly during establishment; moderate once mature | Mildly toxic to pets |
| William Shakespeare 2000 Rose | Direct sun (at least 4-6 hours) | Deeply once or twice weekly through the growing season, more in heat | Pet-safe |
| Willow Oak | Direct sun (at least 4-6 hours) | Moderate; water weekly when young; tolerates periodic flooding once established | 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 |
| 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 |
| Wine Palm | Direct sun (at least 4-6 hours) | Water deeply 1–2 times per week in warm weather, less frequently in cool periods | Toxic to pets |
| Wine-Colored Alcantarea | Direct sun (at least 4-6 hours) | Keep the central tank filled with fresh water; water the root zone when the top 3-4 cm is dry, roughly every 7-14 days | Pet-safe |
| 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 |
| Winter Heath Springwood White | Direct sun (at least 4-6 hours) | Weekly during dry spells; drought-tolerant once established | Mildly toxic to pets |
| Winter Iris | Direct sun (at least 4-6 hours) | Low — drought-tolerant; water sparingly in summer | Toxic to pets |
| Winterberry Holly 'Winter Red' | Direct sun (at least 4-6 hours) | Keep consistently moist; water regularly in dry spells | Toxic to pets |
| Wintersweet | Direct sun (at least 4-6 hours) | Water in dry spells; moderate once established | Mildly 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 |
| 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 |
| Witchgrass | Direct sun (at least 4-6 hours) | Rainfall sufficient in most climates; supplemental water only if very dry | Pet-safe |
| Wonderful Puya | Direct sun (at least 4-6 hours) | Weekly in summer, once every 2–3 weeks in winter | Mildly toxic to pets |
| wood small-reed | Direct sun (at least 4-6 hours) | Drought-tolerant once established; occasional deep watering in first season | Pet-safe |
| Woodland Sage | Direct sun (at least 4-6 hours) | Low to moderate; drought tolerant once established | Pet-safe |
| 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 Rock Jasmine | Direct sun (at least 4-6 hours) | Moderate in summer; very little 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 |
| Worplesdon Sweetgum | Direct sun (at least 4-6 hours) | Weekly during the first 3 years; supplemental watering in dry summers | Mildly 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 |
| 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 |
| 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 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 Bladderwort | Direct sun (at least 4-6 hours) | Lives submerged — keep it permanently in water; top up to maintain depth as it evaporates | Mildly toxic to pets |
| 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 coneflower | Direct sun (at least 4-6 hours) | Every 1–2 weeks during establishment; every 2–4 weeks once established | 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 Dragon Fruit | Direct sun (at least 4-6 hours) | Every 10-14 days in growth; let the top half of the mix dry first | Pet-safe |
| 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 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 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 Horned Poppy | Direct sun (at least 4-6 hours) | Occasionally during dry spells only | Toxic to pets |
| Yellow Ice Plant | Direct sun (at least 4-6 hours) | Every 2–3 weeks during the growing season; minimal to none in winter | Pet-safe |
| 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 Jaboticaba | Direct sun (at least 4-6 hours) | Every 2–3 days during establishment; weekly once mature | Mildly toxic to pets |
| Yellow Latan Palm | Direct sun (at least 4-6 hours) | Every 7–10 days in summer; every 14–21 days in winter | Pet-safe |
| 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 Mombin | Direct sun (at least 4-6 hours) | Every 7–14 days; highly drought-tolerant when established | Pet-safe |
| 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 Passion Fruit | Direct sun (at least 4-6 hours) | Regularly, every 3-7 days, keeping soil consistently moist during flowering and fruiting; never let it dry out hard | Mildly toxic to pets |
| Yellow Pitaya | Direct sun (at least 4-6 hours) | When the top 3-5 cm of soil is dry, roughly every 7-10 days in summer; every 2-4 weeks in winter | Pet-safe |
| Yellow Pitcher Plant | Direct sun (at least 4-6 hours) | Keep permanently wet; stand the pot in 1-3 cm of water during the growing season (tray method) | Pet-safe |
| Yellow Prairie Wild Indigo | Direct sun (at least 4-6 hours) | Every 2 weeks in year 1–2; essentially drought independent once established | Toxic to pets |
| Yellow Rain Lily | Direct sun (at least 4-6 hours) | A dry period of 2-3 weeks followed by generous watering triggers flowers; moderate moisture otherwise | 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 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 Trumpet Vine | Direct sun (at least 4-6 hours) | Every 5–7 days during active growth; reduce in cooler months | Mildly toxic to pets |
| 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-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 |
| Yoshino Cherry | Direct sun (at least 4-6 hours) | Water young trees weekly in dry weather; established trees need little | Toxic to pets |
| Yucca | Direct sun (at least 4-6 hours) | When the soil is mostly dry, every 10-14 days | Toxic to pets |
| Yulan Magnolia | Direct sun (at least 4-6 hours) | Weekly when young; established trees need water during prolonged dry spells | Pet-safe |
| Yunnan Cypress | Direct sun (at least 4-6 hours) | Regular during establishment; drought-tolerant once mature | Pet-safe |
| Za Baobab | Direct sun (at least 4-6 hours) | Twice weekly in summer; once a month or less in winter | Pet-safe |
| Zamia Palm | Direct sun (at least 4-6 hours) | Every 3–6 weeks | 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 |
| Zehtner's Discocactus | 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; reduce to once every 4-6 weeks in winter | Pet-safe |
| Zehtner's Turk's Cap | Direct sun (at least 4-6 hours) | When the top 2-3 cm of soil is dry, roughly every 7-10 days in summer; reduce to once every 3-4 weeks in winter | Pet-safe |
| 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 |
| Zinnia | Direct sun (at least 4-6 hours) | Deep watering once a week | Pet-safe |
| Zinnia 'Benary's Giant' | Direct sun (at least 4-6 hours) | When top 3-4 cm of soil is dry, roughly every 4-6 days in summer | Pet-safe |
| Zinnia 'Profusion' | Direct sun (at least 4-6 hours) | When top 2-3 cm of soil is dry, every 4-7 days; containers more often | Pet-safe |
| Zinnia elegans 'Benary's Giant Coral' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 4-7 days | Pet-safe |
| Zinnia elegans 'Profusion Cherry' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 5-7 days | Pet-safe |
| Zinnia elegans 'Zahara Starlight Rose' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 5-7 days | Pet-safe |
| Zinnia haageana 'Old Mexico' | Direct sun (at least 4-6 hours) | When the top 3-4 cm of soil is dry, about every 5-7 days | Pet-safe |
| 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 |