Christmas Cactus Questions

Christmas Cactus Questions Courtesy of Ron Smith North Dakota State University Extension Service

Q: How do I start a new Christmas cactus from my old plant? Does it work to break off a piece and stick it in some new potting soil? Would this be the time of the year to try to start a new plant? (e-mail reference)

A: Please go to my Web site on Christmas cactus at www.ext.nodak.edu/extnews/hortiscope/houseplnts/xmascctus.htm for all kinds of information on working with this plant. In response to your direct question, here is my answer to a similar question on the Web site. All she needs to do is cut off sections of the stem consisting of two or three joined segments. Allow them to dry for a few hours and then push them into a 3-inch pot that has the same potting soil as the mother plant does. Treat the cuttings as mature plants and in about four to six weeks, the cuttings should have rooted and begun to show some new growth. This will not harm the mother plant. Good luck ________________________________________

Q: I purchased a Christmas cactus that was full of buds and flowers. After a couple weeks at home, all the buds fell off. What would cause this? (e-mail reference)

A: Moving the plant from a florist or greenhouse environment to a home environment in winter where the humidity goes from 60 percent or higher to one where the humidity is 10 percent or less will cause the flower buds to drop. Christmas cactus is a forest cactus that lives in constant high humidity. Eventually, the plants acclimate to our low home humidity settings and bloom beautifully. Be patient. Eventually, the plant will grow ample, beautiful flowers. ________________________________________

Q: I read through all the pages about Christmas cactus care and problems. My plant stems near the soil look like they have been stressed. Some of the leaves have transparent spots on them. I only water when my gauge says dry or low moisture and fertilize with Miracle-Gro. The plant was repotted, so I wonder if I put it in too big of a pot because I know they like to be root-bound. I have another plant that I repotted. Half of the stems broke off and other stems are breaking off. What could I be doing wrong? (e-mail reference)

A: What you are probably seeing is the plant tissue becoming corky because of age. Usually, this is nothing to worry about. As for the leaves that are showing transparent spots on them, if there are just a few, go ahead and remove them. This is often the beginning of edemia caused by keeping the soil too moist. The breakage and falling of some leaves is a pretty good indication of the air being too dry. Keep in mind that these are forest plants that live in the understory of tropical forests. I suggest that you go to http://www.ag.ndsu.edu/pubs/plantsci/landscap/pp744w.htm for further analysis of your plant's problems. Perhaps something at this site will help you identify what the problem is with your plants. ________________________________________

Q: Someone gave me a cactus plant that was supposed to bloom around Christmas. It is now well past Christmas and the plant has not bloomed. What is wrong and what type of cactus is it? (e-mail reference)

A: From the photo you sent, it looks like a Christmas cactus (Schlumbergera species). The reason for nonflowering likely is due to it not having the required number of hours of short days (long nights). The plant should receive 13 or more hours of continuous darkness starting around the end of September or the beginning of October. This action sets the flower buds after about six weeks. For extended blooming, try to keep the plant in a cool setting away from forced-air heating vents or any sudden cold drafts from open windows or doors. ________________________________________

Q: I have a Christmas cactus that is about five years old. The plant never has bloomed, but it has grown quite large. The branches are falling off at the dirt level and some of the leaves are curled. Also, the stocks of some branches have brown streaks and some of the branches are limp. I don't know what to do to correct the problem. (e-mail reference)

A: I suggest visiting my Web site at http://www.ext.nodak.edu/extnews/hortiscope/houseplnts/xmascctus.htm to see if you can pick up some clues for what is ailing your plant. My best advice, based on what you have told me, is to prune off any limp branches and any that have brown streaking on them. You also might want to trim off some of the healthy material as well to reduce the weight that is causing some of the breakage. These plants bloom as the amount of daylight becomes shorter. Christmas cactus can be forced to bloom indoors using the same treatment. My guess is that this plant never has had the daylight shortening requirement met to set flower buds. In order to get this to happen, the plant needs to be covered for about 13 hours each night (absolutely no light reaching it) beginning around the end of September or early October. You didn't say what kind of container it is in or whether it ever has been repotted. Use a free-draining, porous clay pot. ________________________________________

Q: When and how often should I fertilize my Christmas cactus? What fertilizer should I use? The cactus is blooming at this point. Should I fertilize it now or wait until the flowers fall off? (e-mail reference)

A: I have a Web site exclusively dedicated to Christmas cactus at www.ext.nodak.edu/extnews/hortiscope/houseplnts/xmascctus.htm. Basically, wait until the flowers cease. During the spring and early summer, fertilize every 14 days with a 10-10-10 mix or with something similar. ________________________________________

Q: What soil should I use to repot my Christmas cactus? When do I know that I have to repot the cactus? I've had it for years and never repotted it. It's flowering and looks great, although only half of the plant has flowers, which is kind of weird. Last year, the whole thing flowered at the same time. (e-mail reference)

A: You are better off purchasing a high-quality, all-purpose potting soil mixed with about 30 percent sand or what is known as a bromeliad potting soil mix. Whatever product you select, be sure it is a quality product that is pasteurized or sterilized. Try to resist the temptation to repot this plant! It thrives on being pot-bound to flower. If you think it needs soil, add some to the top of the pot. If you do repot, do not step up to a larger size. Wait until the plant stops flowering and then refer to the details on my Christmas cactus culture and care Web site at www.ext.nodak.edu/extnews/hortiscope/houseplnts/xmascctus.htm. Christmas cactus needs more than 12 hours of continuous darkness every 24 hours. Very likely the part of the plant that is not flowering was exposed to low-level light that kept it from setting flower buds. ________________________________________

Q: My mom had three Christmas cacti. They used to be different colors, but now they are all white. Why did this happen and is there a way to make them colorful again? (e-mail reference)

A: You are asking a very good question! If you had said that one plant was changing color, I would attribute that to possibly a genetic material break, but not with all three plants doing the same thing! It must have something to do with the environment or cultural practices. I am sorry, but I can't give you a solid reason at this time. Perhaps some column readers can provide an answer. ________________________________________

Q: I have a Christmas cactus that is full of buds, but the soil is very dry. I am afraid to water it because last year I gave it a nice drink and the buds started to fall off. Should I give it a drink? (e-mail reference)

A: You need to maintain a fairly constant watering schedule with any flowering plant. Reduce the watering a little at this time, but do not eliminate it. I would suggest watering enough to moisten the top few inches of soil, not a good soaking after a dry period. Flowers (leaves too) often will abscise if an extended period of dryness is followed by an irrigation event that completely saturates the roots. ________________________________________

Q: I have a Christmas cactus that is doing great. I would like to clip off some leaves and start a new plant. Should I put the new clippings in water (and for how long) or plant the clippings in soil? (e-mail reference)

A: Both ways are acceptable. If you are going to plant the clippings in soil, I would encourage you to use a sand/peat mix (50/50) and keep the media moist. The clippings should root for you in a few weeks, and then repot the new plants. ________________________________________

Q: I bought a Christmas cactus plant that I water when it is dry on top. Lately I have noticed little, black, gnat-looking bugs on the plant. What is a safe way to get rid of them without killing my cactus? (e-mail reference)

A: I would suggest repotting with fresh potting soil that is pasteurized. These are likely fungus gnats that are feeding on the organic matter in the soil mix, which was probably not a pasteurized mix to begin with. Larry Sagers Horticulture Specialist Utah State University Extension Thanksgiving Point