One of the many rewarding parts about being a cactus grower is there is a type of cactus that can bloom in each season! Winter is no exception, with Christmas Cacti commonly being sold in stores at this time already in bloom. I wanted to take the time to go over some of the basic care for a Christmas Cactus, because even as a horticulturist, there are some plants I struggle with. My goal is to make it so we both get a nice explosion of color from these wonderful plants for the season.
Christmas Cacti are in the genus Schlumbergera and in the family Cactaceae. I had been under the assumption that they were not a real cactus. Where are the spines!? Not all cacti have spines, but they do have areoles. Those are the points that spines come out of, and they are what make a plant a true cactus. As it turns out, the plants in the genus Schlumbergera DO have these areoles.
Now that we have the technical names out of the way, let’s get more into transforming these plants into an eye-catching conversation piece. To truly care for these plants, it helps to know from what type of habitat they come. They grow epiphytically in Brazil, which has a more tropical climate. This means they are not going to be outdoor plants for those of us in temperate regions, with our icy winters. Anyone living in a USDA zone below 10 is going to have to keep these indoors during the colder months. In fact, I personally lost one because I had not checked the weather and there had been an earlier freeze than expected. USDA zones above 10 are fine for keeping them outside.
Although they are technically cacti, their needs are different than what you might expect. These plants grow in a tropical area and thrive with humidity and being partially shaded, as opposed to a desert cactus that can not get enough sunlight and can easily die from having too much water. When keeping these plants in a container, you want to use well-draining soil and keep the soil moist. They do not like to dry out completely, and because they are still succulent, keeping the soil too wet can cause the stem to rot.
Now, let’s get into the showstopping flowers we’re all seeking! The key to flowering is going to be the light/dark cycle and the temperatures to which the cactus is exposed. The light and temperature changes should be employed in September and will produce blooms around Christmas time. The cactus should be kept in the dark for 13 hours per day and in light for the rest of the time. This can be achieved through a windowless basement or by covering the plant. Any treatment that will prevent it from having light for the 13 hours will work. The other important factor is to have lower temperatures during the night time. Below 70 degrees is ideal, and they can be kept down to 45 degrees without issue. A basement may have the right temperature for this as well, or a breezeway/covered porch.
Hopefully, I was able to enlighten you and your Christmas season with these tips. I know that I, and many others, have been unsuccessful in getting these magnificent plants to bloom again after buying them for their flashy flowers around this time of year. I wish you all the best of luck with these lovely plants!
Cody Hoff, Lead Horticulturist