I really enjoy and appreciate beautiful plants, so, it is important to me that I give proper winter care to my Christmas cactus to keep it healthy.
Before bringing the cactus inside for the winter, check it over carefully for any pests. Spray the entire plant with water from a spray bottle. My spray bottle is one pint. I add one tablespoon of mild liquid hand soap to the water. I check the plant for any signs of damage and pick off any parts that have been attacked by bugs. I never cut, but always twist off damaged parts and discard them. I also check thoroughly for any sign of fungus. I have never found fungus on my Christmas plant -- but it is possible to appear if the plant has been over watered.
The first temptation of a plant owner is to set a plant near a window where the plant will get direct sun every day. This will work for many plants, but, not for the Christmas cactus. This plant is tolerant of high light levels, but not direct sunlight. If this cactus gets too much light, the stems will take on a reddish color instead of the healthy dark green. Too little light will prevent flowering. So, it is important to pay close attention to the plant the first time you bring it inside in order to find the perfect spot for it.
The amount of light and darkness the cactus gets is important to make sure it flowers every winter. It should have at least twelve hours of darkness to promote the flower buds. Low temperature can slow down the flowering process. To make sure my cactus blooms during the Christmas season, I have had very good results by letting the plant have 16 hours of darkness for eight days at a room temperature of 61 degrees. My Christmas cactus then has a prominent spot during the entire holiday season.
It is also very important to control the watering schedule. Make sure the soil is never totally dry and never soggy. Keep the soil lightly moist.
Rarely has my cactus had any pest while inside during the winter. However, it is possible for mealy bugs to appear. Mealy bugs look like a very small piece of lint on the leaves (stems). If you see these, place a little isopropyl alcohol in a small saucer and get a cue tip. Dip the cue tip in the alcohol and just touch the mealy bugs with it. The bugs will turn pink, die and stick to the cue tip. Discard the cue tip with the dead bugs in a plastic bag and seal it before tossing in the garbage.