Christmas cactus is a lovely plant, a favorite of many through the years. In your home the light may be a problem. Additionally, providing cool temperatures part of the year is the best way to push bud formation (Mine is in a northeast window with fluorescent light from above).

The jungle cacti widely sold as Christmas cacti are frequently not. The true Christmas cactus is Schlumbergera x buckleyi which typically blooms in December, has purple anthers (the part of the plant that contains the pollen) and has been available for many years. More recently, Schlumbergera truncata in particular has been widely produced and sold as Christmas cactus, holiday cactus or Thanksgiving cactus. Holiday cactus is an apt name, as these plants tend to bloom from November to January. They can also be differentiated from S. buckleyi by the sharper points to their serrated leaves and their yellow anthers.

These plants do best if they have that period of rest after they finish blooming and they need to experience lower temperatures and longer nights to set new buds. If your cactus will not re-bloom, it is most likely that one of these elements has been missed in its yearly routine. In particular, your holiday cactus will not set buds if kept at normal household temperatures above 68° F. in the bud formation period. Bud formation and bloom are also inhibited by the presence of artificial light at night, so household lamplight and even streetlights can be a problem.Thirteen hours of uninterrupted darkness will help buds form.

During the flowering period, keep temperatures above 60°F and water normally. Your cactus then needs a rest period for about two months following flowering. During this time the cactus should be watered less frequently and kept relatively cool (around 55°F). Around April, you can increase water, temperature and re-start your feeding program. About two months before bloom-time, (mid-September) keep your plant dry-ish and cool again until buds form, at which point you can resume regular watering.

Other points of proper care:

Light Preference: Very bright light conditions with at least two hours of winter sun.

Watering: Water thoroughly when top half of soil feels completely dry. It is best to remove all excess water from the holding saucer after 15 minutes. Although actively growing  plants require plentiful watering, they must not be permitted to get waterlogged.

Temperature: To encourage Christmas cactus to set buds in autumn, keep night temperature consistently between 45º and 55ºF. To prevent bud drop, avoid drafts and large temperature fluctuations, keep humidity high, and water correctly. Also, moving plants can cause buds to drop while they are forming.

Maintenance: Removal of spent flowers and stem tips after flowering promotes branching and more flowers.

Potting: Pot plants using a porous mixture.  This can be accomplished by adding one part coarse sand or perlite to every three parts standard potting mix. Propagate by taking 3 to 4-inch stem cuttings in spring or summer. Remove a section of stem consisting of two or three joined segments, allow to dry for a few hours, and push the bottom segment gently into a 3-inch pot of the potting mixture. Insert the segment just deep enough to support the whole cutting. Several such cuttings may be inserted in a larger pot.

For more information, consult our Guide to Tropical Cacti Houseplants.

- Courtesy of NYBG Plant Information Service