Submitted by Doreen Coyne, a member of the Richmond Hill Garden & Horticultural Society
Christmas cactus (Schlumbergera truncata) is also known as Thanksgiving cactus, holiday cactus or crab cactus.
The crab name refers to the leaf-shaped stem segments that have curved, pointed teeth or claws along the edges.
The Easter cactus (Schlumbergera buckleyi) has rounded edges on its leaf segments.
They all originated in southeast coastal Brazil in shady, humid forests. They are classified as epiphytes because they live above the ground in the trees, in areas where branches meet and decomposing fallen leaves and mosses collect.
Some say that the “trick” to getting Christmas cactus to bloom in the following years after purchase comes down to two things: light and temperature.
Christmas cacti produce flowers in a cool, environment when days are shorter. To initiate the production of flower buds, there needs to be at least eight days of 16 hours of dark and eight hours of light each day. Wherever the plant is placed, do not turn on the lights at night, even for a short period of time. I’ve read that to help it blossom, it should be in an east-facing window that receives abundant amounts of sunlight during the day and 12 hours of darkness each night. Two solutions that might help.
My Plant
My plant has been growing for more than 40 years and has blossomed twice a year for most of those years! Once in late November or early December and a second time between Feb and April.
According to www.expressionsofdirt.com, mine is a Thanksgiving Cactus due to its pointed teeth or claws along the edges of its leaves. But I do find various sites use the more common name of Christmas Cactus to refer to all of the various varieties of this plant whether they are actually Christmas, Thanksgiving, or Easter Cactus.
BTW: I also have a “newborn” Thanksgiving cactus which is now about 1 year old. It got a bit sunburnt last summer (thus the reddish colouring of the leaves) but is producing its first set of flowers right now.
Here’s what I do to get it to bloom when I want it to:
First, I leave the soil dryer than normal with less water starting about 6 weeks before I want it to bloom. Then about 3 weeks later, start giving it as much water as it wants. These are not exact durations but give you an idea that it needs to have a dryer time and then be allowed to drink more.
Note:My cactus is in a pot with holes in the bottom and that pot is in another container which is where I put the water. Thus, it drinks at its own pace from the reservoir of water in the second pot. And when it drinks a lot after a few dryer weeks, it tends to start flowering!
My plant sits in a west-facing window so lots of sun when we have a sunny day but November to April can have a lot of dull short days in our area so I believe it is getting the proper lighting to encourage blossoming.
Also, the Christmas cactus is said to grow best when it is “pot bound.” That means leaving it in a small container for as long as possible and then moving up to just a slightly larger pot. They prefer a rich, organic potting mix and should not be allowed to dry out. Increase the amount of water when the plant is blooming. They prefer bright, indirect light. Full sun can cause the leaf segments to turn dark red as the plants begin to burn. My plant has remained in its current pot for 10 years now. So, its roots are likely getting a smidge crowded. Some of you may think that is a long time before repotting it, but its blossoms suggest overwise. This spring after it blooms in Easter it is getting repotted, more to change the soil and ensure it has new good quality soil again. But a slightly larger, prettier vase will be nice as well.
