It seems as though every year since I graduated from Texas A&M, I have been asked how to get poinsettias to rebloom. It doesn’t take long into the discussion before the gardener knows the task is more than formidable. On the other hand, the Christmas cactus, so rare in beauty, is actually easy to grow and rebloom, maybe for the rest of your life. In fact, this is a plant that I often find as a hand-me-down from mom or grandma.
The cacti I used to have in my office were living, blooming proof. Although I had them for several years, they were abandoned for weeks on end during the spring and fall garden season when I was on the road. If they got water or any other light from sitting in a north window, they were lucky.
Every year, however, they rewarded me with their floral displays as if I were a long lost friend, or as if I had been pampering them for months. It was almost incredible. I visited two places before I wrote this to make sure this plant had not fallen out of favor. They were in several different colors. It is amazing that these plants are for sale at these unbelievably low prices.
The Christmas cactus is one of those plants that trigger fierce arguments over its botanical name and even the common name. You would think with a plant this beautiful we could just all get along. First, is it a Christmas cactus or a Thanksgiving cactus? Don’t bring that up at the dinner table; no use fighting.
I am just thankful for it whenever it blooms. Even though my stores selling the plants on Dec. 19 called them the zygocactus, that name is no longer correct. Who cares, right? Botanically speaking, most taxonomical authorities say the Christmas cacti sold are Schlumbergera x buckleyi, which is a cross between S. truncata and S. russeliana. In fact, there are more than 200 named cultivars. Then there are other reputable sources that say, nope, they are Schlumbergera bridgesii. Oh my gosh! I nominate them for Congress.
The bloom period of these hybrids may be somewhat controlled by the amount of uninterrupted darkness the plant receives. You can delay blooming by giving more light. Once the plant receives 12 to 14 hours of uninterrupted darkness each day, buds will usually start to form.
Most of you that have been reading my columns for the past 20-plus years have gathered that I’m a tropical plant nut. Absolutely, and guess where the Christmas cactus is from? This true cactus, minus thorns, is native to the South American rainforest. In Brazil, they grow on tree trunks and limbs alongside orchids and bromeliads, wherever rainwater quickly drains away. Their flowers are almost iridescent in shades of lavender, fuchsia, orange, red and white.
Despite the neglect I gave mine back at the office, it is best to keep them in a bright, cool location. Keep the soil lightly moist, but never soggy. Don’t fertilize until growth begins in the spring.
Once temperatures stay above freezing, you can move the Christmas cactus outdoors for the spring and summer. Keep it in an area that is shaded, especially in the afternoon. Feed with a dilute water-soluble fertilizer every other time you water. Around the first of October next year, place it in an area where it will receive no light for about 12 hours each late afternoon and night. Buds should start to develop around the first of November and open between Thanksgiving and Christmas.
You can start new Christmas cacti by simply taking stem sections of two or three segments and sticking them in very porous, moist potting soil. I actually prefer sand.