5 essentials for Christmas cactus health

by Jacqueline A. Soule, Ph.D.

Although poinsettias rank No. 1 in popularity for holiday plants, the Christmas cactus is a close second thanks to its many charming attributes.

Look closely at the flowers — the petals appear dusted with tiny jewels. Delicate flowers, but tough plants. In the hustle and bustle of the holiday season, who has time to remember to water houseplants? Christmas cactus will forgive you if you miss a week or so while poinsettia will quickly wilt. And finally, Christmas cacti are great for the thrifty — they'll last for years, and can flower again and again.

For those who may not know, Christmas cactus and Easter cactus are the same. Botanically speaking, they're generally either Zygocactus truncatus or Schlumbergera bridgesii, or one of the countless natural and artificial hybrids and subspecies. Whatever they're called, these lovely plants come into our homes from the cooler mountain rainforests of South America.

Cactus in a rainforest? Sure. In the wild, these cacti are epiphytic. They live upon (epi) other plants (phytic). They perch upon the giant rainforest trees and thread their roots into the dead outer bark. They aren't parasitic; they don't steal anything from the trees they live upon.

Among the tree branches, Christmas cactus gets dappled sunlight plus a little rain every day. Its only problem is that the rain runs away, down the tree, leaving the cactus high and dry. Thus, storing water is a necessity. Being a succulent is how these cacti have managed to thrive in tree tops.

Now that you know their origins and how they live in the wild, you can use this knowledge to keep your Christmas cactus healthy and happy year-round.

Temperature — Remember, these plants are from cool mountains. Avoid higher temperatures and keep away from a heating vent. Keeping them indoors all year is preferred.

Light — Keep out of direct sun. Indirect sun, as most of us have flooding our homes, is ample.

Water — Less is more with these plants. Too much water will drown them. Be sure pots have good drainage. Remove or cut a hole in the bottom of decorative wrap for drainage. Place a saucer to catch drips. In general, let the soil dry three days or so between waterings — not bone dry, shrinking away from the sides of the pot, just drier and crumbly, not wet to the touch. Then add water until it trickles out into the saucer.

Soil — When it comes time to repot, cactus mix is ideal. Cactus mix has good aeration and drainage, as well as ample nutrition. But don't worry about this for a while. Christmas cacti have countless threadlike roots and don't do well with frequent repotting. They do best in a pot that looks too small for them.

Fertilizer — For later rebloom, let Christmas cacti rest after blooms are done. Water less through the spring and summer. Toward the end of summer, apply a quarter strength bloom fertilizer when you water, and keep this up until buds form. Once buds appear, keep the plant evenly moist with plain water through the bloom period.

Jacqueline A. Soule is a garden writer based in Tucson, Ariz. She has lived and gardened in almost every U.S. Department of Agriculture zone from 2A to 9B. Everywhere she's lived she's striven to make her yard a haven of serenity.