Schlumbergera truncata

This tough epiphytic succulent has showy flowers that bloom in the winter, usually around Thanksgiving, hence the most popular common name Thanksgiving Cactus. It is also known by many other common names and is sometimes confused with the true Christmas Cactus (Schlumbergera x buckleyi). You can tell them apart because the Thanksgiving Cactus has claw-like appendages on its flat stems (or cladodes) that resemble crab claws, hence of of its other common names Crab Cactus. The blooms on this cactus are erect and do not hang down like the flowers on Schlumbergera x buckleyi. Although this plant is a cactus (family Cactaceae), it prefers the higher humidity of its native Brazilian rainforests. It does not do well in hot arid environments like other cacti. It can grow outside in zones 10 through 12, but in colder zones, it must be grown as a houseplant.  

Plant it in a good draining succulent potting mix and place it in a warm room (57 to 72 degrees Fahrenheit) that receives bright light in the winter and high humidity. In the summer it will need some shade or the stems will turn yellow. Because of their high humidity, bathrooms are a popular spot for growing this plant. Do not overwater this plant. If you are lucky it will bloom a second time as the days lengthen in February. Or you can force it into blooming by exposure to night temperatures of 40 degrees for several successive nights.

When new growth starts in the spring fertilize monthly, reducing fertilizer in the fall and early winter. Repot the plant every three years or so, as it does well being slightly pot-bound.  

It easily propagates through stem cuttings. Remove two or three stem segments with a sharp knife and let it callous over for a few days. Plant in moist, well-draining potting mix and water when the potting mix is completely dry. The stems will take root after a few weeks. Most of the plants sold in stores today are sterile hybrids of S. russelliana and S. truncata. There are over 200 cultivars of these plants giving a variety of flower colors.

Insects, Diseases, and Other Plant Problems:  Reduced flowering or dropping of flower buds can be from inadequate dark hours (at least 13 uninterrupted hours), sudden temperature, moisture, or light changes.  Aphids, red spider mites, scale, and mealybugs are common insect pests.  Root rot can be a problem with overwatered plants.

Quick ID

• Cladodes with acuminate teeth
• Flowers elongated tube, zygomorphic
• Flowers in shades of pink, orange, or white, apex strongly oblique

VIDEO Created by Elisabeth Meyer for "Houseplants, Succulents, and Cacti", a plant identification course offered in partnership with Longwood Gardens.

More information on Schlumbergera.