With a sunny window, growing succulents is easy and rewarding. Cacti are one of the best know groups of succulents, but there are many succulents that are not cacti.
To stimulate flowering, keep plants potbound. Flowers usually occur on new growth.
The majority of cacti need at least 4 hours of direct sun per day. A south window is good. Fluorescent lights may be used. The plants should be set 15-30 centimetres (6 – 12 inches) from the tubes and the lights should be left on for 12 -14 hours per day.
Cacti and succulents are able to withstand reasonably high daytime temperatures with cooler nights, 16-18 degrees Celsius (60-65 degrees Fahrenheit) from spring through to fall. During the winter night temperatures should be 7-13 degrees Celsius (45 – 55 degrees Fahrenheit) with higher daytime temperatures. Cool nights are essential to initiate bloom.
Water weekly with tepid water from spring to fall. Hold back on watering as daylight hours get shorter and only water enough to keep the plants from shriveling in the winter. An exception is Crassulas, which require reverse watering to encourage flowering.
Choosing the Right Soil
Use a soilless mix containing equal parts of a non-peat moss based potting soil and construction sand. Exceptions are Rhipsallis and Hatiora cacti that require a peat based potting soil, regular watering and indirect light. Bone meal may be added to the bottom of the pot to encourage root development.
Use a half strength water-soluble fertilizer with a ratio of 1:2:1 applied once a month from spring to fall. Withhold fertilizing in winter. Over fertilizing can cause soft new growth.
Pests and Diseases
Succulents are not prone to pests. Pick off scale. Forcefully spray spider mites or mealybugs with a stream of tap water. Rot or soft growth is due to over watering or over wet conditions.
Missouri Botanical Garden. Cacti and Succulents. https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Factsheets/Cactus%20and%20Succulents10.pdf
Royal Horticultural Society. Cacti and succulents. https://www.rhs.org.uk/advice/profile?pid=849
Toronto Cactus & Succulent Club. https://www.torontocactus.club
Sajeva M, Costanza M. (2000) Succulents II: The New Illustrated Dictionary. Timber Press
Anderson, M.(2000) The Ultimate Book of Cacti and Succulents. Hermes House
Date revised: August 2021
Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics. Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration. Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.
Statement on Invasive Plants: When choosing plants, avoid invasive plants, which can spread quickly and dominate gardens. Invasive plants are sold by nurseries, big box stores or even at community plant sales. Invasives may already be present in your garden. They can invade gardens by spreading from under a neighbour’s fence or may be transported by wildlife. For beautiful, sustainable options to invasive plants, see the Ontario Invasive Plant Council’s “Grow Me Instead – Beautiful Non-Invasive Plants for your Garden” at https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/ before purchasing or accepting “gifts” of plants.
Statement on Home Remedies: The Toronto Master Gardeners do not recommend home remedies, as these have not been proven effective through scientific investigation, and may even damage other living organisms in the soil or plants in your garden. There are other garden friendly options you can use.
If you have further gardening questions, reach us at our gardening advice line 416 397 1345 or by posting your question here in the Ask a Master Gardener section. To book Toronto Master Gardener volunteers for talks, demonstrations, advice clinics, or other services, please contact us at 416 397 1345 or email@example.com