1234 Schlumbergera x buckleyiCommon Names: Christmas cactus, holiday cactus, Thanksgiving cactus, Easter cactus Family: Cactaceae (cactus Family)
Christmas cacti have fleshy stems that are divided into flattened leaf-like segments with scalloped margins. They do not have spines and they do not have true leaves. The stems start out growing upwards, then droop down as they lengthen. Trumpet shaped flowers with narrow petals develop on the ends of the stems. The bright flashy flowers are bilaterally symmetrical and up to 3 in (7.5 cm) long. Extensive hybridization and selection have resulted in more than 200 named cultivars, differing mainly in flower color, which ranges from white through pink to fire engine red, and even peach, yellow and orange. Most cultivars bloom around Christmas time, but some bloom earlier or later than Christmas. Most of the so-called Thanksgiving and Easter cacti are actually selections of different species, although they can look pretty similar to the real Christmas cactus.
The six species of Schlumbergera are all native to mountainous tropical rainforest near Rio de Janeiro in southeastern Brazil, where they grow as epiphytes on tree trunks. The hybrid species S. x buckleyi was created by an American cactus collector who intentionally crossed the two related species, S. russelliana and S. truncata in 1852.
Light: Christmas cacti growing outdoors like partial or dappled shade. Indoors, they do best in bright, indirect light. Direct sun is not good. The shortening days of autumn and early winter induce Christmas cacti to bloom. Artificial light in the autumn and early winter may inhibit flowering: Christmas cacti need over 12 hours of darkness to begin flowering. Moisture: Christmas cacti do best in a porous, acidic to neutral medium with regular watering. Some sphagnum in the medium is a good thing. The soil can be kept moist during growth, but don’t let it remain soggy. Christmas cacti like a relatively high humidity, too. (Remember, these cacti come from tropical rainforests, not deserts!) After flowering, reduce watering for a couple months, and water only when the potting medium dries out. Hardiness: USDA Zones 9 - 11 Unless you live in a frost-free climate, you need to bring your Christmas cacti indoors or into a greenhouse when it gets cold. Christmas cacti exposed to temperatures below around 50 °F (10°C), may not produce flowers in their best colors. For example, flowers that would ordinarily be white may turn out pink, and flowers that would have been red will be magenta if the plants are exposed to low temperatures. Propagation: Christmas cacti are very easy to propagate from pieces of stem stuck in potting medium.
Christmas cacti ask for so little and give so much. Just keep them out of direct sun, give them ample water during the summer, and let them have naturally shortening periods of light in the autumn, and they will reward you. Their abundant flowers brighten up the otherwise dreary days of winter. Christmas cacti make great windowsill plants (provided they are not in direct sunlight), and are perfect for hanging baskets.
I like to grow Christmas cacti in Herty cups, those old clay pots that were used to collect pine resin for the naval stores industry up until the middle of the 20th century. You sometimes can find them at flea markets and garage sales. The pots have a hole on the side for hanging on the pine trees. I drill a drainage hole on the bottom with a drill bit made for glass and ceramics. Then I hang the pots on trees or around the screen windows on the porch (but always out of direct sun).
In nature the Christmas cacti are pollinated by hummingbirds. If you don’t have the right hummingbird species in your neck of the woods, you probably won’t get Christmas cactus fruits or seed.
Schlumbergera x buckleyi is said as: “Schlumbergera the hybrid species buckleyi.” The genus is named after Frederick Schlumberger, a French collector of cacti and patron of horticultural botany. The specific epithet honors a 19th century American botanist and plant breeder who crossed S. russelliana with S. truncata to create the first of the many selections of Christmas cactus.
Schlumbergera russelliana was originally described in the genus Cereus (in 1839), and S. truncata in the genus Epiphyllum (in 1819), later transferred to Zygocactus (in 1913). Both are now considered to be members of the genus Schlumbergera, although you still may see them and Christmas cactus, the hybrid species buckleyi, listed under Zygocactus. Are we confused yet?
Steve Christman 2/3/15