Certified GKH Gardening Expert
Ok... so Christmas cactus is what's called an epiphyte. This means that the plant typically grows off of the bark of another plant or tree. these guy do not handle transplant very well. I have done a few tests on changing the soil type, but they seem to be sensitive to this. When you re-pot, make sure to re-pot in an orchid soil, as they prefer to grow like orchids, which are also epiphytic. As an added bonus, you can force flowering. The cactus needs a period of long daylight (roughly 12 hours a day or more) for a few months, followed by a short day ( 12 hours or less light per day.) Follow these instructions for a healthy tropical cactus such as this.