Blooms develop on a Christmas Cactus when days are short and temperatures are low. Starting in early fall, place a Christmas cactus in total darkness 12 hours a day. The correct temperature is important if you want a Christmas Cactus to produce flowers. To set flower buds, the plant needs cool temperatures of 60-65°F (16-18°C) during the day and even cooler temperatures of 45°-55°F (7°-13°C) at night. Once buds have developed, Christmas Cactus like warm temperatures of 70°F-75°F (21°C-24°C) during the day and about 10°F (-12.2°C) cooler at night. Cool temperatures between 65°F-70°F (18.3°C-21.2°C) help Christmas cactus flowers last longer.
Pruning a Christmas Cactus helps it become a full bushy plant and produce more blooms during the holiday season. The best time to prune a Christmas Cactus is about a month after it has finished flowering. This brief rest encourages the Christmas Cactus to produce new growth and branch out. You should never prune a Christmas Cactus after the month of May. Pruning a Christmas Cactus is really easy. Just twist or cut one or several of the segments off of the ends of each of the stems. If you want to start new plants, use a three segment section and plant at least two or three of these sections in a small pot. These little plants make great Christmas presents or you can donate them to a local Nursing Home.
Feed a Christmas Cactus every two weeks in the spring and summer with a liquid indoor plant food diluted tc 1/2 the recommended strength. Never feed a Christmas Cactus after October 1st.