The Leftover Kitchen Scrap That'll Help Your Christmas Cactus Thrive

Christmas cacti (Schlumbergera russelliana), especially for those of us northern climes, can be a burst of color enriching homes against a bleak outdoor landscape. The dark green segmented leaves contrast with their colorful blooms add to the holiday cheer of the colder season. Not truly a cactus, this plant is a native of tropical Brazil where they bloom from April to May and are not considered an invasive plant in the U.S. The plant's curious habit of blooming in the middle of winter is cued by the shortening length of daylight and a slight lowering of temperatures. Ensuring those conditions is key to helping your Christmas cactus to bloom on schedule. Keep it away from heating vents and situate it where it will get natural light. Oh, and don't forget to give it a cup of Joe from time to time. Yep, Christmas cacti like their coffee!

Well, to be more accurate, Christmas cacti respond very well to using coffee grounds as a soil conditioner and a version of homemade fertilizer. Watering the plant with an actual cup of coffee would be far more harmful than beneficial. In their native environment they live on well-drained hillsides and prefer neutral to slightly acidic soil, which is why coffee grounds are such a helpful hack to enhance your Christmas cacti. (Just one of many ways to reuse old coffee grounds.) Let's dive into how to use them to help your Christmas cactus thrive.

Coffee grounds contain nitrogen, phosphorus, and potassium, but in relatively low amounts. However, they are very high in carbon content. As they come out of your coffee maker, it is likely better to call them a soil amendment or conditioner than fertilizer. As such, adding a moderate amount of grounds directly to the pot your cactus is growing in will be a benefit — conditioning and adding drainage to the soil. The coffee grounds may also change the soil's pH to be slightly acidic, which Christmas cacti are fond of. At that point, there is a bit of discussion regarding whether the coffee grounds will be providing nutrients to the plant or the microbes in the soil – which is a bit of a difference without distinction, as your plants need microbe-rich soil and nitrogen, phosphorus, and potassium. But the point is don't overdo the coffee grounds, and here is why.

The high carbon content of coffee grounds will begin to break down, and as it does, it will actually capture the existing nitrogen in the soil, reducing its availability to the plant. But that process also "feeds" beneficial soil microbes. If you want to get the best bounce for your buck, put the coffee grounds into a mulching situation with high-nitrogen-bearing waste (the browns and greens in mulching theory). There, it will break down both components and become a highly beneficial all-around fertilizer. At that point, generous applications of this mulch/fertilizer product will benefit your Christmas cactus greatly.