When asked what you think of as a Holiday plant, most will quickly think of the Poinsettia. But unlike the Poinsettia, there is a showy plant that reblooms annually with very little care—the Holiday Cactus. If you are unfamiliar, the Holiday cactus is a spineless cactus with very showy blooms.
The Holiday cactus is in the Schlumbergera family which is a small family of only six species. The schlumbergera truncata (also zygocactus) is the cactus that is marketed as the Holiday cactus. If it blooms in November, we call it a Thanksgiving cactus: if it blooms in December, we call it a Christmas cactus….and sometimes they can bloom at Easter! It is also called a crab or claw cactus because of the crab-like appendages on the flat leaf-like segments.
The Schlumbergera are true cacti native to Brazil. They are found in the rain forest and share space with orchids and bromeliads-not in sandy, dry deserts.
The blooming of the Holiday cactus is affected by day-length and temperature. There are a few secrets to maintaining good blooms: proper temperature and light control-especially temperature. Buds will develop and bloom if they have bright light and short days (less than 12 hours of light per day), and night temperatures less than 70 degrees (and they prefer 55-65 degrees). If they are left outdoors in the fall, they get the shorter days and cooler temperatures naturally, and set a copious amount of flower buds. If the temperature is lower than 55-60 degrees (but not below freezing), they will set flower buds regardless of the length of the day or night and might rebloom in February and March. The Holiday cactus should never be exposed to freezing temperatures.
After exposure to cool temperatures and short days for six weeks, flower buds are produced. If you treat your plant as a houseplant year-round and keep your house at 70 degrees or above, you will most likely never see a bloom. It NEEDS the cool period to set flower buds.
Many researchers have looked at the practice of forcing blooming by ‘a dry period in the fall’. The real answer is that this will decrease blooms. The Holiday cactus does not like its soil to get bone-dry or water-logged. Water thoroughly, allowing it to become moderately dry between watering. They bloom best when they are slightly pot-bound. Repotting is only necessary every two to three years. And when you do repot, increase the pot size gradually.
As the blooms develop, give the plant a bright sunny window, but watch for flower buds dropping off it the temperature is too high or humidity is too low.
After blooming, locate the plant in some direct light. Full sun is helpful in midwinter indoors, but full sun during summer months can make plants look pale and yellow. In nature, these plants grow shaded by a canopy of leaves.
If you have an older plant that has not yet bloomed and shows no signs of flower buds, OR your cactus has already bloomed and you would like it to bloom again, move the plant to a very cool room in your home that gets bright light, or place near a cool window.
Most of the growing of the Holiday cactus is done April-September. For the summer you can move the plant outside for full morning sun and afternoon shade. Keep the plants evenly moist and fertilize monthly.
Holiday cactus are relatively disease and insect free. New hybrids are offering a wide range of flower colors. They are a welcome gift to give and receive. With just a bit of care, they are a plant that just keeps giving.