By Joy Johnson, Master Gardener
A long time ago, I thought growing cactus would be a piece of cake. Just set the little cactus I’d picked up at Home Depot on the window sill, ignore it for six months and then give it a little water. I thought I would be extravagantly rewarded for all my effort. NOT! Within a month the cactus had shriveled up and died. I did some research, mostly to convince myself that it really wasn’t all my fault it had died, but I found out it was. Short and sweet, here is what I’ve learned about growing cactus over the years.
First, they need a growing medium that is 60% sand/small gravel and 40% cactus potting soil. Second, it is best to grow them in a traditional, non-glazed clay pot with a clay saucer underneath the hole in the bottom of the pot. This allows them to dry out thoroughly between waterings. Third, they should be watered once a week, not flooded, but enough to get the soil thoroughly wet. Don’t water them if they are not all the way dry. Fourth, they need light. In the winter my cacti (all 52 of them) are in my house in front of south and west facing windows. They go semi dormant in the cool basement and only need ¼ cup of water every two weeks. This allows them to rest. In the spring, I bring them upstairs, where there is more light, and give them a little cactus fertilizer (half the recommended dose) with every other watering.
When outdoor day time temperatures are above 65 degrees and all chance of frost is past, I move them all outdoors. If possible, a week in a shaded area is a good transition before placing them in full sun. Because I have so many, they don’t all get treated to shade before being placed in the full sun, I simply don’t have the space. A few have gotten sunburned spots on them, but all have survived. It doesn’t matter if they get poured on by a summer thunderstorm. They seem to love the extra moisture, as long as they are in pots that drain and can dry out. I occasionally fertilize them during the summer, but not too often. It’s important to place them out of harm’s way, where they won’t get blown over, or bumped by passersby. In June and July, you may be rewarded by these stunning blooms. They only last 24 hours, but they are simply breath taking. This year, we had one cactus that bloomed in both June and July (usually they only bloom once a year).
Christmas and Thanksgiving cactus also enjoy being outside in the summertime. Make sure they aren’t in full sun, they definitely like it a little shady. We have one large cactus that I call a dragon’s head cactus because it’s flowers really look like a dragon head with its mouth wide open. Every summer I’ve put it outside, it gets tiny brown spots all over it. I bring it in before the first frost and it rewards me with blooms in January. The brown spots fade once it’s been in the house for a month or so. I’m thinking it doesn’t like being outdoors, even in the shade. But I like the extra space I have in the house during the summer once all 52 cactuses have been moved to their outdoor summer homes!
I don’t know the scientific names for all our cactuses, many seem to have been mislabeled, simple called “Euphorbia” or my favorite, “cactus”. We just enjoy them, after all a cactus by any other name will still look stunning.