How to Grow Christmas Cactus
They may not look like cacti, but Christmas cactus are a member of the cactus family. They come in two varieties. Schlumbergera x buckleyi is the familiar Christmas cactus that blooms in December. Schlumbergera truncata which has larger leaves that resemble crab claws, blooms in November and is known as a Thanksgiving cactus.
Their natural environment resembles orchids. They grow in the leaf litter that accumulates in the crooks of trees. In your home, they should be grown in potting soil that contains a lot of peat moss which encourages good drainage. Like cacti, they prefer dryer conditions. Unlike their desert cousins, they prefer a higher humidity. You can create humidity by placing a glass of water next to your Christmas cactus or by placing the pot in a humidity tray which is a tray with gravel and water.
For most of the year, your Christmas cactus likes warm temperatures, 70°F - 80°F. You can even bring them outside during the summer. Don't place them in direct sunlight, however. They prefer diffuse light indoors and shade outdoors. During the growing season (April through September), you can use a 10-10-10 fertilizer once a month.
Propagating your Christmas cactus is simple. Cut off a Y-shaped piece making sure that it includes at least 3 segments. Dip it in rooting hormone and place it (about ¼ of the first segment) in a soilless mix until it develops roots at which time you can transplant it into regular potting soil. It's easy to tell if there are new roots. Simply look for the red buds at the tips of the Y indicating new growth.
Preparing your Christmas cactus to bloom during the holiday season takes a little planning. In September or October, move your Christmas cactus to a cool spot (50°F to 55°F) that is sunny during the day but gets total darkness at night with no artificial light. In late October or early November, switch to a 0-10-10 fertilizer to encourage bloom. Limit watering. Once the plant has developed buds, be careful not to bump it or move it. This could cause the buds to drop off. Other causes of bud drop are lack of humidity, over-watering and not enough light. Cold drafts will also cause your Christmas cactus to drop its buds so don't place it near any doors.
After blooming, your Christmas cactus needs to rest. Continue lightly watering and suspend fertilizing it. Resist the temptation to repot it until February and don't prune it until new growth appears in March or April. You can resume fertilizing with your 10-10-10 fertilizer in April.
These few simple steps will ensure that your Christmas cactus will bloom every Christmas (or Thanksgiving) for years to come.