The Christmas cactus is a popular houseplant during the holiday season, and you may find that it stays with you through the year if you treat it as a houseplant or live in a warm climate. Its pink flowers blossom in November through February, which explains how it earned its festive name. Since Christmas cactus likes an acidic soil pH hovering between 5.5 and 6.2, coffee grounds are an excellent additive that will provide nitrogen and keep the soil acidic.1
How to Care for Your Christmas Cactus
Most succulents originate in desert climates and require dry soil, but this unique cactus is native to Brazilian rainforests and will need more water than most. However, like all succulents, this plant is susceptible to root rot, so you should still keep it in a well-draining pot away from direct light, such as in a sunny room or shady garden. You should make sure the coffee grounds have dried out before scattering them in the soil so that you know how much moisture your plant is receiving.
Plan to water your Christmas cactus every two or three weeks, or when the top third of the soil is dry. When it’s time to water, place your pot under the faucet and run until water leaks from the drainage hole. Put your pot on a saucer to catch the water until it completely drains from the pot. After about 15 minutes, dump the water out of the tray and return your cactus to its home. It’s important to remember to pour the water out of the tray because root rot can easily occur if your plant sits in water.
Because the Christmas cactus came from a tropical climate, your plant might enjoy a cozy, humid spot in a sunny bathroom or on a shady porch. Just be mindful of how much sunlight and water it receives because direct sunlight, abrupt temperature changes, and excessive moisture are the main causes of death for this plant.
Why Coffee Grounds May Help your Christmas Cactus
Used coffee grounds have a pH of 4.5-5 depending on the beans. Coffee beans contain nitrogen and excellent antioxidants that nourish plants (and you!) While you shouldn’t use coffee grounds directly on plants that require neutral or basic soil, the Christmas cactus likes the acidity of coffee grounds since it has a soil pH of around 5.5-6.2.
Even if coffee grounds may be beneficial, they still come with risks. Half a tablespoon of used coffee grounds contains 41 mg of caffeine, which is a moderate amount. Some studies have shown that the caffeine in coffee grounds may cause accelerated plant growth for a season—followed by the sudden death of the plant a short time later. However, the studies have had mixed results and some researchers speculate that caffeine’s effects may be more plant-specific than general. Decaf coffee grounds mediate more of the risk if you don’t want to take a chance with your cactus.
If you decide to use coffee grounds on your Christmas cactus, spread the used grounds on a paper towel to dry before sprinkling them in your pot. You should only add coffee grounds a couple times a month as fertilizer.
The colorful Christmas cactus thrives on acidic soil, making coffee grounds a good additive as a natural, nitrogen-containing fertilizer. Since this cactus is prone to root rot, you should dry the grounds before sprinkling and keep your plant in a well-draining pot. Decaf coffee might be the best choice since there haven’t been enough studies to conclusively determine caffeine’s effect on plant growth.
Featured Image Credit: Vikki Lambert Kimbrough, Pixabay