Question: This image shows a Christmas cactus that was given to my husband when he was born 66 years ago. The wilting stems will eventually die. Each year I lose more of it. What can I do to take care of this Christmas cactus better?
Answer: First let's say that you must be doing something right, since you are getting this Christmas cactus to bloom, and continues to live!
When thinking about the preferences of the Christmas cactus, it may be helpful to understand that these plants aren't "cactus" in the typical sense of the word. They aren't native to dry, sunny, sandy deserts. Instead, they are found growing naturally in jungles, where they grow not in the ground but on top of tree branches.
Here are the basic "likes" of a Christmas cactus growing as a houseplant:
- Airy, fast-draining soil. Add coarse sand or perlite to regular houseplant potting mix to improve drainage. Repot the plant each year after flowering ceases. This will ensure the soil doesn't become compacted around the roots and suffocate them. Remember, in nature this plant's roots grow in debris that accumulates in the crooks of tree branches—very fast to drain and airy.
- Bright light, with no direct sun.
- Soil that's consistently moist when the plant is growing or flowering, with a post-flowering dry period. For 8 weeks after the plant finishes blooming, keep it in a cooler location and water it only sparingly, to allow it to rest.
- Humid air—increase humidity by misting the air around the plant and/or siting the pot on or near a dish of damp aquarium gravel.
Limpness can be a sign or root rot, which can set in if the soil remains soggy and wet. However I strongly suspect that your plant may simply be showing signs of its great age. Your best bet may be to propagate a new plant from it. Just clip off a healthy-looking stem and insert it in moist potting mix. In a few weeks, it will likely have formed roots. (Tug on it to see.) This new plant will be more vigorous in growth, and you'll feel good having it on hand in case the older plant continues to fade.
Ron Smith, horticulturist with the North Dakota extension service, has a helpful web page with answers to many cactus questions.
Show off a humidity-loving houseplant with a glass cloche or terrarium.
Get a guide to common houseplant tasks for under $5.
Here's a great reference: The Complete Guide to Cacti and Succulents.