| 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 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 |
| Achachairu | Bright indirect light (just back from a sunny window) | Water abundantly and consistently year-round; do not allow to dry out. | Mildly 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 |
| Achimenes 'Tarantella' | Bright indirect light (just back from a sunny window) | Keep evenly moist in growth, roughly every 4-6 days | Pet-safe |
| Adriatic Bellflower | Bright indirect light (just back from a sunny window) | Weekly during spring and summer; minimal in winter | Pet-safe |
| Aesculus hippocastanum | Direct sun (at least 4-6 hours) | Water young trees weekly to establish, then rely on rainfall | Toxic to pets |
| 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 Milk Tree | Bright indirect light (just back from a sunny window) | Every 1-2 weeks in spring/summer; roughly every 3-4 weeks in winter | Toxic to pets |
| African Violet 'Optimara EverFloris' | Bright indirect light (just back from a sunny window) | When the top of the soil feels just dry, about every 5-7 days | Pet-safe |
| 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 |
| 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 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 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 |
| Aglaonema Golden Bay | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | Toxic to pets |
| Aglaonema Prosperity | Medium indirect light (a couple of metres from a window) | When the top 3-4 cm of soil is dry, roughly every 7-10 days | 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 |
| Akebia quinata | Bright indirect light (just back from a sunny window) | When the top 4-5 cm of soil dries, about every 7-10 days while establishing | Mildly toxic to pets |
| Akebia trifoliata | Bright indirect light (just back from a sunny window) | When the top 4-5 cm of soil dries, about every 7-10 days while establishing | Mildly toxic to pets |