Your Thanksgiving/Christmas cactus may have Edema, also called Oedema. This leaf condition happens on plants for a variety of reasons, and to discover why it might be going on do the following: 1. This sometimes happens when a plant is root bound and the roots are now clogging the drainage hole, or the potting mix has gotten very compact and broken down. If your plant has been in the same pot for awhile it probably needs a new pot with new potting mix. Be sure the pot has a drainage hole and don’t put any rocks, shards etc in the bottom of the pot.
2. If this plant is sitting in a saucer of water frequently it may be happening because it’s being kept too moist. Edema often occurs when plants are taking up more moisture than they respire – it can be an issue in the winter if the plant is in a cool room as well.
3. Plants in soil that is low in potassium and calcium are more prone to edema – fertilize with a good, all round houseplant fertilizer used according to directions.
About the Author: Garden Answers
For the first time ever, one of my Christmas cacti ( about 15 yrs old) has NEW growth but it is curled ? What is that from…The rest of the leaves appear OK…just the new growth at the tips.