A quick show of hands, how many of us have a “Christmas” cactus withering away in our homes? With fascinating information, and some tender love and care, one of our La Plata County master gardeners, Clint Kerns, offers some very helpful information about the number of things we can do to actually see these beauties bloom and thrive again.
– Heather Houk
Whether you call it a Thanksgiving, Christmas or Easter cactus, it is botanically known as a Schlumbergera.
Schlumbergera russelliana is one of the main parent species of the Christmas cactus hybrids. There are more than a half dozen hybrids showing different leaf shape, color and size. The major “holiday cactus” varieties are:
Truncata: Thanksgiving cactus has distinctly pointed leaf edges and typically blooms from late fall.
Buckleyi: Christmas cactus has less pointed leaf segments and larger flowers, typically blooming from early to midwinter.
Gaertneri: Easter cactus blooms from late winter into spring, with more numerous star-shaped flowers and distinctly rounder leaves.
Schlumbergera naturally occur only in the tropical coastal rain forests of southeastern Brazil, where they naturally grow as epiphytes or lithophytes, thriving on tree branches and rocky ledges. Neither location provides continuously damp soil. They are adapted to dappled light from a dense jungle canopy.
You should be forming an idea of how out of place these “cacti” are in a store, let alone a house in a Southwest desert, growing in commercial potting soil. Is it any wonder that they rarely bloom and quickly look poorly or die?
Here are some best practice tips to help your cactus thrive:
- Don’t over water. Many plants suffer from too much water rather than too little. The best method is to go by feel. Stick your finger an inch or two into the planting medium. If it feels just damp, it’s OK. If it feels wet, don’t add water. It is best to wait until it feels dry before watering it again.
- To maintain the correct moisture level, the key is the soil. As for epiphytes or lithophytes, the best planting medium is a mixture of sphagnum “peat” moss or coco coir, perlite, sand or orchid bark, which provides structure and drainage while mimicking their natural tree branch or rock crevice home.
- The ideal way to plant them is to mimic their natural growing environment. A hanging basket or wall sconce planter is the ideal home but be sure you can move the planter easily into a closet or basement to control light exposure. A closet? Why would I put it in a closet? Don’t plants need light? Ah, so here is the most interesting thing about Schlumbergera. One more science word: photoperiodism. These plants are photoperiodic, meaning they depend on specific changes in light to set buds and bloom.
- Schlumbergera need 12 to 15 hours of complete and uninterrupted darkness, even glow from a street lamp or TV screen is enough to prevent bud formation. If it’s not practical to move the plant, you can cover with a light blocking cloth. Start six to eight weeks before Christmas or whenever you want it bloom. Manipulating this is cool because you can amaze your friends with a Christmas cactus blooming in July, called a fireworks cactus.
- In addition to controlling light, you need to control temperature. During regular growing season, Schlumbergera prefer a moderate temperature of 60 to 75 degrees. During the period when you are trying to stimulate bud development, they should be held at a consistent temperature without drafts of 50 to 55 degrees. You can see why a basement is an ideal location.
- The final care considerations are humidity and fertilizer, so misting is beneficial. Once a day is not too much, one a week is not enough. You should fertilize a few times through the year with a general purpose 10-10-10 fertilizer, or slow-release feed of 14-14-14.
OK, that’s it. You are trying to keep a tropical plant happy in the desert, so Schlumbergera will require a lot of care, but the reward can be spectacular in a few years.
Clint Kerns, a master gardener for the La Plata County Extension Office, filled in for Horticulture and Agriculture specialist Heather Houk this month.
