Christmas Cactus (Schlumbergera) make great houseplants because they're easy growers and reliable bloomers. And they love growing in our hydroponic system!
Even though they're called cactus, these plants are different from common desert cactus. Rather than growing in the desert, they grow in the same "tropical" conditions most houseplants grow in. Since they're "tropical cacti", their cultural requirements are different from true cacti.
Christmas cactus require bright light with some direct sun. If you're growing outdoors in the summer, avoid direct sun however. Protect your plants by putting them in partial shade.
These plants enjoy thorough waterings with a dry period in between. That's easy with hydroponics! Simply water to 1/2 on gauge and then wait a week or so AFTER THE WATER GAUGE READS EMPTY.
In nature these plants get by on slim diet of bird droppings, decaying leaves, and anything else that comes their way. Apply a low dose of fertilizer (1/2 recommended strength) on a regulars basis. I use (and recommend) Dyna-Gro Grow 9-7-5 formula at 1/4 tsp per gallon.
Applying a "Bloom" fertilizer WILL NOT make your plant bloom. These plants have internal calendars that tell them when to bloom. Flowering is triggered by temperatures in the 50 degree range in the fall.
Christmas cactus grow in a wide range of temperatures without complaint I've grown good looking plants in poorly vented greenhouses where temperatures reached 100 degrees or more during the summer and dropped below 50 degrees at night in the winter (the plant in the photos above is one of those plants!).
Christmas cactus also like at least 40-50 percent humidity - especially when blooming. If your house is dry during the winter, think about improving humidity levels for happy plants and longer lasting blooms. A good way to increase humidity is with our Humidity Trays.
Grower Tip: Christmas cactus have internal calendars that tell them when to bloom and you can't change it. Your goal is to give the plant the right growing conditions during Sept-Nov that will trigger blooms. _______________________________________________________________
The Key to Getting Your Christmas Cactus to Bloom is Cool temperatures at night.
Starting in September or October, move your plant to a room where temperatures drop to around 50 degrees at night. If you're growing outdoors, simply leave your plants outside until evening temperatures drop into the 50 degree range. Don't expose them to freezing temperatures however.
This may not be as difficut as it sounds. Choose a window where you can close the heat vents. When the weather turns cold outdoors, the windowsill can be 15-20 degrees cooler than the rest of the room. (A Hi/Lo Thermomter is a good way to measure this.)
Light: Continue with bright light and some sun. Try to keep plants away from artificial lights in the evening because that can interfere with setting blooms. Commercial growers go to great lengths to keep plants totally dark for at least 12 hours to insure blooming.
Water: Be stingy with the water. With hydroponics that means pouring water over the pebbles until the water gauge moves, then stop. Lift inner pot to make sure everything is totally dry before rewatering - usually about 2 weeks. Skip nutrients altogether during this period.
After the blooming season is over, give your plant a resting period of a month or so. Put it in a cool room and water it just enough to avoid dehydration. Simply wet the pebbles every week or so. Don't worry if your plant loses a few leaves and appears weak during this rest period.
After a month, start the new growing season by increasing water and nutrients.