How To Grow Cacti Indoors

When you buy

Look for clean plants with no visible scars or evidence of insect damage. Make sure there is no discolouration—a sign of rot from within. Gently feel the plant for firmness in the pot. Look for any signs of weak spindly growth caused by lack of light. When transporting the plant from the store to your car, make sure your new cactus is in a plastic bag and well insulated from the cold Canadian winter winds.


The main thing to remember when watering is that over the entire year indoor cacti need far less water than any other plants. How much water they need depends on a number of conditions. Most plants in Canada grow inside a house, at least in winter! At that time of the year most plants in normally heated rooms will need light watering every two months. With the coming of spring, gradually increase watering to once every two weeks. Plants in smaller clay pots may need watering every week if grown on a hot sunny windowsill. With the arrival of fall gradually reduce the frequency until around November when the winter schedule can be reintroduced.


Fertilizing should be done in the spring and summer months. Use one of the many specially formulated mixes for cacti available in every houseplant section of the local supermarket. Be sure to follow the directions carefully.

Blooming period

With the many thousands of cactus species, you are sure to find one that is in flower every month of the year. The main blooming time is, of course, the spring and early summer.

Dormant period

The key to successful flowering of your plants is the ability to provide them with a cool dry period from around November to March. The cooler and drier the better. This is not so easy in Canadian homes. There are a number of things you can do to help:

•If you can, place the plants in a well lit room, which is used infrequently.

•If you can, shut off or at least turn down the heating in that room. Water infrequently or not
at all if you can keep the room really cool.


A heated greenhouse that receives direct sun for most of the day is the ideal place to grow these plants. Most of us, however, do not have that luxury. If you live in an apartment, you need a sunny south- or west-facing window in which to put your plants year round. If you have a house, the same applies in winter, but in summer you can put most of the species outside for the summer months in a sunny protected part of the garden. Acclimatize them slowly (bring them out for a couple of hours at a time for the first week) so that they do not scorch because of the “sudden” exposure to sun rays.


Many proprietary brands of special “cactus soil” are available in almost every big convenience store. Most of these brands are pretty good; although like with all modern potting soils a good fertilizing program is required. The main thing to remember is that soil in your cactus pot must drain exceptionally well.


Clay or plastic pots are both suitable for these plants and each kind has its followers. Clay pots dry out sooner and may need slightly more watering.