Article posted form 2022 December e-newsletter
The Christmas cactus is a favorite plant for the holiday season. With a little bit of care, these plants will provide many years of beautiful holiday blooms. Some plants can last over 100 years. There are reports of 200-year-old plants that have been handed down for generations.
Christmas cacti are short-day plants. They will bloom when they days grow shorter (9-10 hours of light) and temperatures grow cooler. They like bright indirect light. A Christmas cactus will have significant buds by late October or early November. Flower buds form best when the plant is kept in temperatures between 50 and 60°F
You can kickstart the budding process by exposing the plant to temperatures of about 45°F (7°C) for several nights in a row. You can also keep the the plant in a dark space for a several days. Withholding water before short days start will stress the plant and may improve bud set.
All the holiday cacti thrive in well-drained potting soil high in organic material. You can add some sand to increase the weight. A good soluble fertilizer, such as 20-20-20, is recommended every two weeks until bud set.
Once your plant has buds, reduce fertilization to about once a month. Water every 2-3 weeks, but only water when the top one third of soil feels dry to the touch. Don’t let the plant get bone dry. Over-watering is a major problem for all succulents. Make sure the pot has a good drainage, and that the plant does not sit in water. They really don’t like wet feet.
Common causes of flower bud drop include:
- Too much water or not enough water
- Exposure to cold drafts or too warm temperatures
- Over-fertilization
- Rough handling
If your cactus sheds its buds one winter, don’t worry: it should bloom the following year!
Insects aren’t usually a problem. If you see mealy bugs, aphids, and scale wipe away with a cotton swab dipped in alcohol.
Once the flowering season is over, the growing season begins and the plant will produce new vegetative growth. Maintain temperatures of 70-80 degrees for the best growth. They will tolerate temperatures of 90-100 degrees, but growth may be inhibited.
Prune plants in late spring to encourage branching and more flowers. Cut off a few sections of each stem; the plant will branch from the wound. Place the cut pieces in a lightly moist potting soil—they root easily after a few weeks.
Christmas, Thanksgiving, or Easter cactus?
Credit: www.extension.iastate.edu
The key to identifying which type of holiday cactus you’re looking at is the leaves. Christmas cactus leaves have a tear-drop shape. Thanksgiving cacti leaves have more of a pointed, claw shaped ends on the leaves. Easter cacti are more rounded with little hair-like growths on the ends. Most cacti sold as Christmas cactus are actually the Thanksgiving variety.
Thanksgiving cacti (Schlumbergera truncata) bloom from late fall to mid-winter
Christmas cacti (S. x buckleyi) bloom from early winter to mid-winter.
Easter cacti (S. gaertneri) bloom from later winter to mid-spring.
Sources:
https://aggie-horticulture.tamu.edu/parsons/search.php?category=Christmas%20cactus
https://www.extension.iastate.edu/linn/news/it-thanksgiving-christmas-or-easter-cactus
https://www.almanac.com/plant/christmas-cactus
by Lea Sandoz, ECMG