Daniel Gill, Merrill, Thomas A. | 11/22/2005 4:13:36 AM
By Dan Gill
LSU AgCenter Horticulturist
One of the most delightful plants we use to decorate for the holidays is the holiday cactus. And yes, despite the fact that these plants don’t have spines, they are true cactuses.
Better yet, with proper care, they will produce their gorgeous flowers for you during the holidays year after year.
The "uncactus" appearance of these plants has to do with where their relatives live in a natural environment. They do not live in deserts but instead come from the rainforests of Brazil – where these plants are epiphytes and spend their lives perched up in trees with their roots in pockets of decaying organic matter lodged in cavities along branches. That explains much about how we need to care for these plants to keep them healthy.
The original species used to develop holiday cactuses are Schlumbergera truncata, the Thanksgiving cactus, and Schlumbergera russelliana, the Christmas cactus. The Thanksgiving cactus is distinguished by sharp teeth-like edges on the flat stem joints, while the Christmas cactus has rounded scallops on the edges of its flat stems.
Breeders have crossed these species together, however, and the plants you purchase these days are not true Thanksgiving or Christmas cactuses but are generally hybrids of the two and have teeth, rounded scallops or something in between. For that reason, we have adopted the name "holiday cactus" to refer to these plants that will bloom anytime from November through January. Breeding has produced more robust, upright plants that are easier to grow with larger flowers in a greater color range.
Choose a holiday cactus that has flowers the color you prefer, such as red, magenta, pink, rose, lavender, white, salmon, pale gold and orange. It should have mostly large buds that are showing color and a few open flowers.
It is very common for young flower buds to drop from a plant once you get it home, primarily because of rapid changes in the plant’s growing conditions. Place your holiday cactus plant in a brightly lit location, such as by a window, so that it gets plenty of light. Avoid heat sources, and choose a location that tends to stay cooler, especially at night. Also, don’t allow the plant to dry out when it is in bloom, or its buds will drop. Water often enough to keep the plant evenly moist (generally, water when the surface of the soil feels dry). Each flower generally lasts about five to seven days, and the plants remain in bloom for two to three weeks.
After flowering is finished, allow the soil in the pot to feel dry when you stick your finger in it before watering. If you displayed the plant in a location other than a bright window, move the plant to a window. There is no need to fertilize.
Care After The Holidays
Come spring, you may continue to grow your plant indoors, or you can move it outside for the summer. When placed outside, plants can receive some morning sun, but shade for most of the day is preferred.
Do not keep the soil too moist. The result of excessive watering is root rot – the most common reason people kill these plants. You can help reduce the chances of overwatering by growing your plants in loose, fast- draining potting soil that is rich in organic matter. Fertilize your plant with your favorite slow-release or soluble fertilizer following label directions.
Repot your plant only if it is no longer stable in the pot it is growing in and tends to fall over. If repotting, choose a pot only slightly larger than the one in which it was growing. To help with the stability of these sometimes top-heavy plants, grow them in heavier clay pots rather than plastic, although either works well.
Getting Holiday Cactuses To Bloom
Holiday cactuses are triggered to bloom by long nights and/or chilly nighttime temperatures. That generally means more than 12 hours of darkness and temperatures below 65 degrees.
This is easily achieved by leaving or placing your plant outside in late September where it will receive naturally long nights and chilly night temperatures in October and early November. Just remember not to place the plant where porch lights, flood lights or street lights shine on it, and bring the plant inside if nighttime temperatures will fall below 40 degrees.
Beginning about September, allow the soil to dry out more before watering, and stop fertilizing your plant. When you begin to see the little buds forming at the tips of the branches, water often enough to keep the soil evenly moist, but do not keep it constantly wet.
Move the plant indoors when the buds are about an eighth of an inch long, and place it in a window for display. If the branches are pendulous and hang down, boost up the pot so the branches hang gracefully.
Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at www.lsuagcenter.com. A wide range of publications and a variety of other resources are available.