I always considered the true Christmas cactus to be the heirloom one my elderly aunt grew, which had rounded tips and dangling magenta and red flowers. I assumed that the new Thanksgiving cactus, which boasts the claw-shaped tips shown in the banner image along with horizontally held flowers in a variety of colors, must be just a young whippersnapper by comparison!
However, I recently read that the old-fashioned Christmas cactus was created in the mid-1800s when British botanist William Buckley crossed the Thanksgiving cactus (Schlumbergera truncata) with an Easter type (Schlumbergera russelliana) to get Schlumbergera x buckleyi. Hence, the hybrid-indicating “x” in the heirloom’s name.
So, the “old” Christmas cactus pictured just above (with its photo rotated for convenience) apparently really is the younger type, being a “child” of the more recently introduced Thanksgiving cactus below, which is the one most often sold as Christmas cactus these days. As if this family weren’t already confusing enough!
At any rate, just before she went into a nursing home, my aunt gave me the small and “clawless” Christmas cactus which had been growing on her windowsill. That one and a subsequent, yellow-flowered Thanksgiving type I purchased went “the way of all flesh” much too quickly—at least the way of green stem-segmented flesh!
I wisely avoided growing Christmas cacti after that until I spied a particular attractive pale pink type with scads of buds at a local department store recently. Of course, as soon as I brought it home, those buds started dropping like flies. This, I learned, can happen due to any kind of stress, including a change in location, temperature, and/or watering.
I’ve been careful to keep the plant well-watered and the foliage continues to look pert and perky. (Because these are rain forest plants, they shouldn't be allowed to dry out as much as desert cacti do. However, they also require fast-draining soil, so they don't rot.)
I have to admit that the 80 degrees at which my dad likes to keep the thermostat—accompanied by the sunny, south-facing windowsill on which I set the plant—probably was too drastic a change from the low light and chillier conditions at Walmart. And, due to its Brazilian rain forest origins, this plant apparently prefers to keep its cool.
Because it grows on trees beneath the rain forest canopy, bright, indirect light often is recommended for the Christmas cactus. However, one greenhouse guide I consulted specified that growers should keep the plants at 1500 to 3000 footcandles, and anything over 1000 footcandles usually is considered the equivalent of direct sun.
Therefore, I’m guessing that an east-facing windowsill might be the best location for Schlumbergeras both old and new, since morning sun provides bright light without the heat of more scorching afternoon rays. Growers apparently keep their plants in the 60s Fahrenheit, with temperatures rising as high as 70 degrees during the day.
If you intend to leave your Christmas cactus indoors year-round, choose a room which typically isn’t lighted during the evening hours in autumn, since long nights help spur the plant into blooming each year. Or you just can cover the cactus with a box which excludes all light for 13 to 14 hours each night, beginning in mid-September and keeping up that routine for six to eight weeks.
Alternatively, you can leave the plant outdoors for as long as possible in autumn, since cooling temperatures also should cue it to make buds. I would bring it in before those buds get very large, though, or the shock of the change may cause a blood bath, ...er, bud blast.
The Rest of the Year
Some sources recommend that you provide the plant a rest period once it has finished blooming, keeping it at 50 to 65 degrees for the remainder of the winter and cutting back on the amount of water you give it. When spring arrives, you can begin treating it as you would any other houseplant, being careful to place it in bright shade rather than full sun if you move it outdoors for the summer.
And, if you don’t already have one of the old-fashioned Christmas cacti, you may want to talk an older relative into giving you a cutting—and provide it better care than I did my little plant. The heirloom hybrid doesn’t seem to be sold in stores anymore, and we want it to remain in the pink for many Christmases to come!
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Photos: The banner image is a stock photo. The other photos are my own.