Crab Cactus Schlumbergera

The holiday cactus is a genus of succulent plants in the cactus family (Cactaceae) that are native to Southeast Brazil and are technically epiphytes that grows in humid rainforests—a very different habitat from the "typical" cacti of Mexico and the Desert Southwest. This genus includes the Christmas and Thanksgiving cactus. It has fleshy stems, showy flowers and grows well as a houseplant, preferring moisture but adapting to a variety of home environments. One plant can live for over a hundred years, so a well-cared for specimen will brighten your living space for decades to come. The genus name, Schlumbergera, honors the Belgian horticulturist, Frederick Schlumberger.

This genus of cactus thrive in bright, indirect sunlight, but they are intolerant to direct sun. Periods of lower light in the fall will encourage winter blooms. They are day-length sensitive, initiating flowers as day lengths and seasons change. Consequently, they bloom more reliably when grown away from artificial light sources. The soil should be moist, well-drained potting mix including sand or perlite to encourage adequate drainage. Water the plant about every 1 to 2 weeks or when the soil is nearly dried out. They also benefit from high humidity and prefer temperatures between 70 and 80 degrees Fahrenheit during their growing season. The secret to good flower production is bright light, night temperatures between 55 to 65 degrees Fahrenheit, and uninterrupted nights of at least 13 hours from mid-September until mid-November. If your plant does not flower, chances are, it is getting artificial light when it needs total darkness. They may be propagated by stem or root cuttings.

This genus of cacti has an upright, pendulous, or trailing habit. They have connecting green, glossy, flat, leaf-like pads or stem segments that are spineless. They are also serrated on each side with clusters of soft bristles at the end of each segment. The flowers are 3 inches long, tubular-shaped, and are available in a variety of colors including shades of red, pink, or white. They typically bloom in November and December. The flowers may also produce fleshy fruits.

Cultivated Schlumbergera cacti are often confused with species now placed in the genus Rhipsalidopsis, and species have been moved back and forth between the two genera. The Easter cactus is now called Rhipsalidopsis gaertneri. The taxonomy of these cacti is still somewhat unsettled, and the species may be listed under synonymous names in catalogs, books and websites.

The plants in this genus are low-maintenance and are the perfect indoor ornamental during the holiday season. The showy, vibrant flowers will add color to your home when planted in containers or hanging baskets.

Quick ID Hints:

• Segmented stems (cladodes) that may have serrate or crenate margins
• Areoles at the tips, where the flowers and/or hairs emerge
• Zygomorphic flowers at the stem tips in shades of pink, orange, red, and white

Insects, Diseases, and Other Plant Problems:  Potential insect problems include mealybugs, scale, spider mites, and aphids. Overwatering can cause root rot and mush stems. Long night periods of 13 hours are required to produce flowers. Buds may drop due to sudden changes in temperature, light or from the lack of water.

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