Of all the beautiful gift plants available in garden centers at this time of the year, the Christmas cactus seems to have the most longevity once gotten home.
Potted, forced bulbs and Jerusalem cherries are one-shot deals.
Greenhouse azaleas aren't hardy here.
Poinsettias may stay alive for many months, but the colorful bracts fade and are almost impossible to rejuvenate.
The Christmas cactus, however, is one plant that houseplant lovers pride themselves on maintaining from year to year. My mother kept one for more than 20 years, enjoying beautiful blooms every December on a plant that ultimately reached almost three feet in width.
My gardening friends seem to be divided into two camps when it comes to Christmas cactus. They either enjoy almost effortless success ("Really, I don't do anything special"), or they give up in disgust after watering and feeding and dusting a plant that never blooms after its initial spectacular display.
Although these plants are the type of cactus mostly commonly grown in American homes, the relatively unattractive foliage, or rather, stems -- this species doesn't technically have leaves -- just doesn't make it worthwhile for most people, without the prospect of some winter dazzle.
But the blooms are spectacular. The available colors, soft through fiery, run the gamut of reds, oranges, purples and even whites. The long, trumpet-shaped flowers form at the end of fleshy segmented pads that, when long enough, arch gracefully over the pot.
The term cactus is somewhat misleading in the case of this plant because its native habitat is not an arid desert but the tropical jungles of South America. The plants are epiphytic cactuses. In other words, they grow on, but are not parasitic to, other plants. Most are found growing in moist, decaying vegetation, fairly high up in trees where they can get as much light as possible.
There is more than one type of Christmas cactus. But even the botanists are confused by the lineage and the traits of plants we see for sale in garden centers that look like Christmas cactuses. Basically, there are two groups: the traditional Christmas cactus (usually labeled Schlumbergera truncata x buckleyi) and what is often called the Thanksgiving cactus (Schlumbergera truncata, aka Zygocactus).
Besides blooming at an earlier date, the Thanksgiving cactus has stem segments with more spikes and teeth than the Christmas one. It is also characterized by asymmetrical blooms, as opposed to the regular shapes of the Christmas cactus. According to observations at Brookside Gardens in Wheaton and at the Department of Agriculture greenhouses in Beltsville, the Thanksgiving cactus is also more difficult to grow to a large size due to a sensitive root system. Both kinds come in many colors.
The leap from the Brazilian jungle to a Howard County window sill is fairly dramatic. A potting soil that drains well and is high in organic matter such as peat or compost will best mimic the Christmas cactus' natural growing conditions. Drainage is particularly important, especially as the plant get larger. Its root systems is very delicate and easily damaged by any undue watering.
Theories on how best to achieve December bloom are varied. Everyone seems to have their own systems that work, even if they are just plain neglect.
The experts agree on a couple of points. One is that these cactuses have an annual rhythm that will, under ideal conditions, culminate in a profusion of flowers. After blooming, the plant needs a cool bright spot for a resting period, when watering should be minimal (don't let the stems shrivel) and fertilizing stopped.
Early spring marks the time for new vegetative growth, which the gardener can aid with regular feeding and a little more water. New segments grow at the tips of each stem, eventually creating a densely branched plant. During the summer, many gardeners here in the county place their cactuses outside in a partly shady location for another period of relative rest.
Now comes the controversial part: how to trigger flower buds to form.
Experts agree that the plants must have cool conditions during the fall.
How cool? One local gardener says that two nights at 40 degrees Fahrenheit always does it for her plants.
Horticulturists at Brookside Gardens say a constant temperature in the 50s will give good results. If temperatures are up in the 60s, day length also seems to enter the picture, and plants should not be exposed to light after sundown until buds have set. This may mean moving them to a closet or basement each evening. Regular temperatures above 70 degrees seem to discourage flowering altogether. If you have a system that works, keep doing it.