How to care for and reflower your Christmas cactus
The recipe for success for caring and reflowering your holiday plant, the Christmas cactus.
The holidays can be a dangerous time to be shopping. Even the grocery store has cute, small, blooming plants like Christmas cacti to entice you when you are at your weakest. If you are listening closely, there is the soft murmuring of, “Come on and just buy me. I’m cute with bright flowers and am so reasonably priced. I’ll be yours for many years.” It’s those Christmas cacti luring us with shiny leaves and brilliant, exotic flowers. Many of us succumb to the sirens’ song and purchase one. But now what? We want the plant to be a permanent resident, not just a flash of flowers and then die. Michigan State University Extension horticulture educators and Master Gardener hotlines receive calls about the care and feeding of Christmas cacti after the holidays.
Christmas cactus or Schlumbergera bridgesii is a hybrid epiphytic cactus originally from Southeast Brazil growing in tropical rainforests. It has been part of the houseplant community for a little over 150 years. Being epiphytic means that it lived in the treetops and branch hollows in mosses and decayed leaves above the ground. Because of this, repotting Christmas cacti in organic, humus-rich soil is important. They also grow better when they are “pot bound,” which means the container and root system are about the same size.
Many non-gardeners think the “cactus” name implies the plant thrives in poor soil and hot, dry conditions. Nothing could be farther from reality for this cactus. Smart gardeners do a bit of background investigation about plants they invite into their homes and try to match growing conditions to each plant. When you have the botanical name, searching for information is simplified.
Christmas cacti require bright, indirect light or filtered light and enough moisture that the potting material does not dry out. However, plants can be too wet as well as too dry. To prevent mineral and soluble salts buildup, it is best to water with rainwater or melted snow at room temperature. If using rainwater isn’t possible, the plant can be repotted in new, clean organic soil once a year.
The method to get an established Christmas cactus to bloom involves temperature and light. Keeping the plant at cool, nighttime temperatures of 50 to 55 degrees Fahrenheit and daytime temperatures of about 65 F during October and November will initiate the development of flower buds by December. Those lovely flowers can come in red, pink, peach, white, orange or purple. The amount of light plays a big part in this. The plant needs continuous, uninterrupted darkness for 14 hours and a bright to medium window exposure for the remaining 10 hours. However, if the plant is in a room where lights are even turned on for a short period of time, the flower party is over. This is why some Christmas cacti bloom on the side of the plant with a window exposure, but have no flowers on the lighted room side.
Some people will cover the cactus with an up-ended cardboard box or put it in a closet for the 14 dark hours. A simpler method can be used if there is an unused room in the house. Putting the Christmas cactus close to a window in a room where the light is not going to be turned on during the 14 hours of blackout can work. Some cacti are not as sensitive about the temperature as the light requirements. Monitor the amount of light and a floral display can be yours.