Mention “cactus,” and there are usually a few people who get nervous, remembering childhood encounters with the prickly desert dwellers. But some cacti have found another way into our hearts, by growing on the treetops of tropical forests among orchids and bromeliads. These plants, generically called holiday cacti (Schlumbergera x buckleyi), are much better companions than most of their spiny kin you may be more familiar with.

Holiday cactus is easy to rebloom if you follow a few simple rules.

Photo Credit: Dr. Gerald Klingaman

Some holiday cacti have pink and white bicolor flowers.

Photo Credit: Dr. Gerald Klingaman

Holiday cacti actually have an identity problem, because gardeners never know what to call them. Most bloom from November through January. We Americans call the early blooming cultivars “Thanksgiving cacti” – a name meaning little to the rest of the world – while those blooming around the yuletide season are “Christmas cacti,” which only fits if you live in the Northern Hemisphere. (And don’t confuse holiday cactus with Easter cactus – that’s another species entirely.)

Whatever it’s called, holiday cactus makes a fine, easy-to-care for houseplant, although admittedly, the flat green, jagged-edged braches are a bit uninteresting much of the year. But gardeners know the joy of anticipation, and once buds begin swelling on this plant in October, all is forgiven.

Holiday cacti are among the easiest flowering houseplants to rebloom, rewarding even minimal effort with a good annual display of blooms that last three to four weeks. They’re available in a variety of colors – mostly centered around shades of pink – but choices range from white to yellow and lavender to red. (Bicolor selections are also available, usually white with pink or red.)

The flower bud formation on holiday cacti is well-understood by floriculture researchers. Either cool temperatures or short day conditions – such as those in fall – trigger flowering. If the average temperature is below 60 degrees F, flowers form regardless of day length. But if the temperature is in a more hospitable range between 60-80 degrees F, plants initiate blooms once nights are longer than 12 hours, which occurs after the vernal equinox on Sept. 21.

Little effort is needed to take advantage of the conditions that trigger flowering. Simply leave the plant outside during summer and fall and allow the changing season to do what comes naturally, then bring plants inside around mid-October. It takes about six weeks from the time buds are first visible in October until plants bloom. (Allowing your holiday cactus to dry out once buds begin to form will result in the buds dropping from the plant.) Once the plant is moved inside, provide bright light such as in front of an east-facing window, uniform moisture supply (water when the top half of the soil in the pot feels dry to the touch) and keep it away from heater vents to ensure the buds continue to develop.

Once your holiday cactus has bloomed, treat it as you would any houseplant. When the danger of frost has past, move the plant outside to an area with bright light, but not direct sunlight. Fertilize occasionally and water as needed. Remember, holiday cacti are epiphytes of the forest canopy. They’ll tolerate dryness, but they shouldn’t go too long without water during summer.