Monday, December 7, 2015
In September and October, Christmas cactus plants should be kept in a cool room where temperatures will remain around 50 degrees, give or take a few degrees. Be sure not to expose them to freezing temperatures. It's also very important they be kept in a room where no artificial light will be turned on at night.
The proper light exposure, correct temperatures and limited watering are the key to getting Christmas cactus to flower during the holiday season. During the fall months, the Christmas cactus should be placed in a spot where it receives indoor indirect bright light during the daylight hours but total darkness at night. (Much the same exposure you would give a poinsettia except a Christmas poinsettia requires warm temperatures whereas the Christmas cactus needs a spot where the temperatures are cool during the fall months.)
Since the Christmas cactus is a tropical plant it will require watering on much the same basis as any other type of tropical plant. A good procedure to follow is to water the plants thoroughly and then allow about the top inch of soil to dry before watering again. However, during the fall and winter months, the plants should be watered less frequently in order to get them to bloom.
Christmas cactus require about 50 to 60 percent humidity. So it's a good practice to place a glass, vase or tray of water near the plant. As the water evaporates it will provide the humidity the cactus needs. A humidity tray is another method of providing the humidity the Christmas cactus requires. This is done by filling a waterproof saucer with gravel, then adding water halfway up the gravel. Place the pot on the gravel surface.
In late October or early November, make an application of a 0-10-10 type liquid fertilizer. A second application of this fertilizer can be made in February. During the growing season from April through September, fertilize the plants with an all purpose liquid houseplant type fertilizer. The fertilizer you use should have a nitrogen ratio of no higher than 10 percent. Of the three numbers on a fertilizer container, the first number is nitrogen.
After The Christmas holiday season, the Christmas cactus should be given about a 30 day rest. Again place it in a cool room and provide limited water. Don't worry if it loses a few leaves or joints and appears weak during this rest period.