Sauk County Gardener: Holiday cactus
“Christmas waves a magic wand over this world, and behold, everything is softer and more beautiful.” ~Norman Vincent Peale
I’m looking forward to seeing my holiday cactus bloom. I’m not sure I’m going to see any blooms right away even though I thought I followed the recommended schedule for bringing my cactus up out of their dark, cooler location in the basement. It’s supposed to get 12 to 14 hours of total darkness about six to eight weeks prior to when you want it to bloom. It was dark down in the basement, but I didn’t ensure they had uninterrupted darkness. Also, I brought it up when I thought I started to see buds; now I’m not so sure they were really forming. I do believe I may have jumped the gun a bit.
You may have noticed I said “holiday” cactus. Technically, there are three kinds of holiday cactus – Thanksgiving, Christmas and Easter. Typically, you are going to find the Thanksgiving cactus in the stores at this time of year. The easiest way to tell the difference is to look at their segments. The Thanksgiving cactus (Schlumbergera truncata) has claw-like segments with pointy “teeth” on the side of each segment. The Christmas cactus’ segments (Schlumbergera bridgesii) are more rounded, scalloped or teardrop-shaped. The Easter cactus’ (Rhipsalidopsis gaertnerrii) segments have very rounded edges. If you have a holiday cactus that is putting on buds or purchased one from the store, place it a brighter, warmer area of your home. It should bloom for about four to six weeks if you don’t move it around much and give it proper care. Holiday cacti prefer humid conditions but do not like heavy watering. Soil should be dry to the touch before watering. There is no need to fertilize when the plant is blooming. If your house is particularly dry at this time of year, fill a plant saucer with pebbles or small stones. Then add water to just cover the stones and set and place the potted cactus plant on top of the saucer. This can help provide the additional humidity these plants like. The plants also like to be root-bound so don’t be overzealous in repotting. This is never a problem for me; I really should repot my houseplants more often but it’s a task I tend to avoid for one reason or another.
One common problem is bud drop. This can be caused by a number of things: Moving the plant too much, exposure to drafts, too high of temps, too low of light, under or overwatering, low humidity, and fumes from a gas-burning stove. A sunny window location that isn’t drafty, a pebble-and-water-filled plant saucer for the plant to set on, and regular watering schedule will help manage this problem and most others. Then you just need to resist the urge to move the plant around. This is a problem I have when I have plant that is blooming nicely. I want to move it to a new location where I can appreciate its blooms – many times that’s not the ideal location for the plant, however.
Irregular amounts of water -- underwatering and then overwatering to compensate -- is another common problem. As these plants are succulents, it’s not uncommon to notice that they are underwatered until it’s too late. Most people then overwater to make up for the shortage. If you underwatered your plant, it’s best to try and bring it back to health slowly with smaller, more frequent waterings than one big overwatering.
Overwatering can cause the plant to become waterlogged and the remaining roots to rot. Overwatering can also create blister-like spots on the segments. This can also be caused by low light and temperature drops at night. If the blisters burst, the cause dead corky tissue on the segments. Of course, you still need to deal with mealy bugs, spider mites, aphids, and sometimes fungus gnats, especially if your plants “summered” outdoors. I now have one that has fungus gnats. Fungus gnats like moisture so this one is a little wetter than it should be. In addition to making sure I let the cactus’ soil get dry on top, I’m going to water that one from the bottom and make sure it doesn’t have any water in its saucer until the gnats go away. I’m also going to fill a little container of cider vinegar, water and dish soap and place the container on top of the soil to attract and drown them. The recipe is one part vinegar to one part water and a couple drops of dish soap – this works for fruit flies as well.
Take care of your holiday cactus and it will reward you with beautiful blooms – in many cases for years to come.
Jeannie Manis is a Wisconsin-certified Sauk County Master Gardener volunteer. If you have any gardening questions, please contact the Extension Sauk County by emailing to trripp@wisc.edu or calling the University of Wisconsin Madison Division of Extension Sauk County office at 608-355-3250.
