Yesterday I was asked by a customer why her Christmas cactus (Schlumbergera) doesn’t bloom at Christmas. It’s a simple answer it has to do with light. Less light equals blooms. Why? So really cool nature fact, the plant wants to pollenate but can’t do it on its own so it makes these colorful flowers in lower light to attract bees and other pollinators to help it. In lower light those flowers look really attractive. Take your cactus about 6-8 weeks before you want it to flower and put them in the dark for 12-14 hours per day for a month. A closet will do just fine you will see buds form and in 6-8 weeks beautiful flowers!
I always recommend keeping them near windows but be careful a simple street light can keep the plant from producing buds. Temperature for buds needs to be between 55-60 degrees Fahrenheit so this can be tricky especially if the window has a heater under it. Mine does so I have my Christmas cactus in the only window that doesn’t and tell my wife I’ll fix the drafty window next year. She doesn’t know it’s my cactus window. I always plant my cactus in cactus soil but Christmas cactus are not desert cactus they actually are rainforest cactus originally from the southeast coastal mountains of Brazil. They tend to grow in between tree limbs so I like to mix 50% orchid mix with 50% cactus soil to give them more of what they find in nature. So follow the steps below and you’ll see some great results.
1. Fertilize in the spring a month or two after the flowering is done.
2. Move if possible outside to a shady area. Watch the watering and use a slow release or organic fertilizer (I prefer fish emulsion)
3. Move indoors before frost. Spray with insecticide and I always change the soil and move to a clean new pot. Watch your watering!
4. Put in dark closet 12-14 hours a day for a month
5. Put near window (preferably drafty with no more that 6 hours of light a day and not street lights!) keep lightly moist