If you mention the Christmas cactus to friends, you're likely to hear stories of people who've had them for decades, but have never been able to get them to bloom at all, let alone near their namesake holiday. And you can't blame them, because care for this plant can be a bit confusing. With the right conditions, though, it can be a beautiful houseplant that gets passed down for generations.
About This Plant
The Christmas cactus (Schlumbergera bridgessii, or Schlumbergera × buckleyi) originated in the coastal mountains of southeastern Brazil, where its parent plant clings to shaded trees and rocks in the jungle. The leafless green stems form flat, segmented pads that grow in a cascading pattern. Under the conditions (see below), the plant may produce white, pink, or red fuchsia-like flowers multiple times a year, although it's named for its winter-blooming habit.
According to the ASPCA, the Christmas cactus is non-toxic to both dogs and cats.
Care and Planting
Despite the name, in many ways you need to treat a Christmas cactus more like a tropical plant than a cactus. It is not a desert cactus, and instead thrives in conditions closer to the ones you'd provide orchids. Plant in a light-weight, free-draining soil, such as a succulent or cactus mix or African violet mix, in a pot with drainage holes. Water it thoroughly and regularly, letting the top inch of soil dry out between waterings. Fertilize every two weeks during the growing season (approximately April through September).
The Christmas cactus prefers bright, indirect light and temperatures between 60 and 70 degrees for most of the year. It can be damaged by too much direct sunlight, and needs to be kept away from drafts, heaters, ducts, and fireplaces. Although usually grown indoors, the Christmas cactus can actually survive outdoors in United States Department of Agriculture zones 9 to 11. It cannot tolerate any frost or snow and needs to be well-watered and protected from any temperature extremes.
Although tight quarters may encourage flowering, repotting every two or three years may be necessary. The best time to do it is after it has finished flowering, during late winter. Repot in a new container only slightly large than the old one, and make sure that it has drainage holes in the bottom.
If you want your plant to live up to its name, and bloom around Christmas, it might require some advance planning. It needs a period of dormancy before blooming. In October or November, cut back on the watering and make sure it receives 12-14 hours of darkness and average temperatures around 50-55 F. For the best chance of flowers, you can place the plant in a dark closet where it won't receive any light for 13 hours each night (set a timer so you don't forget about it!) until buds begin to form. After the blooming period, let it rest again, keeping it in cool temperatures and watering infrequently until about the end of March.
Post-flowering is also a good time for pruning to help make the plant bushier, which will also provide you with cuttings for propagation.
The Christmas cactus is a relatively easy plant to propagate. Take cuttings of one to four segments and let them sit in a cool, dry place for two to four days. Plant an inch deep in new soil, preferably a sand/peat mix. Water sparingly until roots or new growth develop, then water as normal.