I feel that I must confess. I'm a crazy collecting Christmas Cactus closet connoisseur. (Yes, I also have a fondness for alliteration). I can't help but purchase any new color of Christmas cactus I run across. There surely must be some twelve-step program to help me. Hi, I'm ProfessorRoush and I am a Christmas Cactus addict....
There is, in my estimation, no easier houseplant to grow than the Schlumbergera sp. epiphytes, otherwise known as Christmas, Thanksgiving, or Crab Cactuses (Cacti?). I should reveal that at one time I grew over 30 orchids, 15 Christmas Cacti, a handful of African Violets, and some assorted other houseplants. When we went away for Christmas one year, somehow the heat for the house got turned off and upon our return one week later, I found one frozen upstairs toilet that had to be replaced and a whole bunch of dead orchids and violets. The supposedly tropical Christmas Cacti survived somehow. Or maybe it wasn't such a miracle since one plant hunter has described collecting specimens in areas of overnight temperatures down to 25F. I've got one fuchsia Christmas Cactus that's been alive for 20 years and has produced umpteen offspring. How many other houseplants do you grow that can claim such longevity in the face of the desert-like house conditions and the poor care of a typical homeowner?
Most of the year, they sit there in my windows, dark green and healthy, needing water only about every other week and a repotting in organic matrix every third year or so. But now, around Christmas, they bloom forth to add to the colorful holiday. I know there are lots of instructions available for bringing them into bloom by exposure to cold nights and decreasing photoperiods, but mine are right on schedule this year, aided only by the decreasing light level of the insulated windows they sit next to. They're even quicker to bloom if you've got them in an old house with single-pane old-style windows. If you have to resort to trying to force buds, flower buds will form reliably by providing 16 hours of darkness daily for 8 days at 61F temperature.
I've seen no insect predators on the plants and the biggest danger to their survival is by overwatering them; remember that these are succulents and treat them as such. An overwatered Christmas Cactus will shrivel up and become limp, which just encourages more watering by the unwary, killing the plant. Most sources say to keep them away from strong light sources such as South-facing windows, but yet mine seemed to thrive this Summer outside, placed in a corner of the house where they got full Eastern and Southern sun exposure from sunrise through about 1:00 p.m.
The easy reproduction by rooting stems of Christmas Cactus makes me look like a genius to the friends who have benefited from the divisions I've given away. To propagate them, twist off pieces of stems one to three segments long and then allow them to dry for 3-4 days to allow formation of a callus at the broken end. Planted into a suitable humus-rich medium, they'll usually then root quickly in warm environments.
Native to the moist coastal mountain forests of south-eastern Brazil, Schlumbergera are leafless epiphytes with segmented green stems. The tubular downward-facing flowers, composed of 40 or so petals that are actually "tepals", are adapted for pollination by hummingbirds, although my Christmas Cacti won't ever benefit from the arrangement here in Kansas. You can find named cultivars, but typically all the cacti we ever see for sale locally will be labeled only by color. The white Christmas Cactus above is, however, named "White Christmas", and I think the true red one at the left may have been "Kris Kringle". But, whatever their names, at this time of year when everything outside is bleak, brown and drab in Kansas, I welcome the color they bring to the interior of my house. And at least I can say that I'm able to keep a houseplant alive.
By the way, according to the dictionaries I can find, either "Cacti" or "Cactuses" is the correct plural. Evidently, for once, we're allowed to choose.