Christmas cacti (Schlumbergera hybrids) are popular houseplants, often living for many years and being passed down through families. If they are to flower during the holiday period, then they need special care during the fall.
- Find a cool spot. The key to getting your Christmas cactus to flower is to find a cool spot for it. A temperature of around 50 F is required for 6-8 weeks to trigger flowering, so move your Christmas cactus into a cool room during the fall.
- Control light levels. During this period, the Christmas cactus needs bright light during the day, and absolute darkness at night.
- Water sparingly. Don't over-water. Make sure the compost is drying out before adding more water.
- Protect from drafts. Don't position your Christmas cactus by doors or windows that will be opened -- they don't like drafts.
- Watch out for flower drop. If flowers form, but then drop, the usual causes are low light levels, drafts or over-watering.
- Feed. In November, give your Christmas cactus a dose of a 0-10-10 liquid feed (i.e. no nitrogen) to encourage flowering.
- After Christmas, feed the Christmas cactus with 0-10-10 again in February, and repot if necessary (although they flower better when pot bound). If you want to propagate more plants, pot up leaf sections in March or April. Revert to using a balanced liquid feed in spring.