If you’re lucky, you could receive a Christmas cactus as a gift this holiday season. This common house plant blooms during the Christmas season, but its long green arms are attractive throughout the year. With cultivars in a rainbow of colors, it is a plant worthy of appreciation. These 10 facts about Christmas cacti will help you to care for your plant if you're given one this holiday season.
1. It’s called a “cactus”, but it thrives in cooler temperatures. Christmas cacti need to be kept away from heat sources. According to the Purdue University Extension Service, a Christmas cactus will blossom longer when exposed to only cooler temperatures. For best results, put your Christmas cactus in a cool place -- away from heaters and fireplaces -- where there are not frequent drafts. Big changes in temperature can cause the cactus blossoms to drop off the plant before they open. Optimal temperature for Christmas cacti is 68 degrees Fahrenheit.
2. Christmas cacti need light to bloom. According to Purdue University Extension Service, keeping your Christmas cactus plants in a sunny location indoors is the key to prolonged blooms. However, if you move them outside during the summer, you’ll have the most success in a partially shaded location, as too much direct light can burn the leaves.
3. The Christmas cactus is native to Brazil. These epiphytes (a plant that grows on top of another plant non-parasitically) grow in the Brazilian rain forest, among tree branches, according to Clemson University Cooperative Extension. Since they are tropical plants, they thrive in humid conditions.
4. Christmas cacti need their beauty sleep. The horticulture experts at the Cheyenne Botanic Gardens recommend setting your Christmas cactus in a room where you never turn the lights on at night. In order for the flower buds to set, Christmas cacti need 14 hours or more of continuous darkness per day. However, after the flower buds have set, Christmas cacti can withstand light at night.
5. Unlike the other Christmas favorite, Poinsettia, Christmas cactus is not toxic to dogs and cats. Poinsettia is famously poisonous to dogs and cats. However, according to the ASPCA, if Fido or Fluffy nibbles on a Christmas cactus, she should not experience irritation or vomiting like she would from the sap of the Poinsettia.
6. Christmas cactus can live for 20 to 30 years. Can you imagine passing a living, flowering plant on to your children or grandchildren? According to the Old Farmer’s Almanac, when properly cared for, Christmas cacti can live for 20 to 30 years. If you provide long nights starting around October 1st, you can force the Christmas cactus to bloom year after year. Cool night temperatures also encourage it to bloom.
7. Overwatering will kill Christmas cacti, but they like to be misted on a daily basis. A horticulturist at the Oregon State University Extension Service recommends only adding water to the soil that a Christmas cactus is planted in when the soil is dry to the touch. Instead, gardening expert and radio host Walter Reeves, the Georgia Gardener, suggests misting the leaves of the Christmas cactus to maintain the desired level of humidity around the plant.
8. 5 diseases commonly infect Christmas cactus. Penn State University Extension experts provide a handy fact sheet outlining the plant diseases that most often affect Christmas cacti. Their list includes: Basal stem rot, botrytis blight, impatiens necrotic spot virus, phytophthora root rot, and pythium root rot.
9. Fungus gnats, flower thrips, and root mealybugs are the pests that most often infest Christmas cacti. The biggest culprit in attracting pests to Christmas cacti seems to be overwatering. Preventative care, such as discarding infested plants, is another recommended tactic. Pesticides are available for commercial growers, although home gardeners may not be able to get their hands on those pesticides.
10. By the way, that Christmas cactus you are buying is probably not actually a Christmas cactus. Surprise! According to the U-Mass Extension Service, “Holiday cactus is sometimes marketed as Christmas cactus, Thanksgiving cactus, or Zygocactus. True Christmas cactus is an interspecific hybrid of Schlumbergera truncata and Schlumbergera russelliana that originated about 150 years ago in England. It's a common houseplant but not often grown commercially. Plants have segments with rounded margins, ribbed ovaries, and purplish-brown anthers. The correct Latin name for Christmas cactus is Schlumbergera x buckleyi; the "x" indicates that it is an interspecific hybrid. Most commercial cultivars of holiday cactus are actually Schlumbergera truncata, commonly known as Thanksgiving cactus or Zygocactus.”
For more advice on caring for your plants, consult a qualified landscaper.
Updated December 11, 2017.