Question: I have a large healthy healthy-looking Christmas cactus. Its flower buds fall off, and only two or three remain to open fully. What can I do to prevent this? – J.K., Naugatuck, Conn.
Answer: Overwatering,especially in the fall as plants come into bloom, will cause the Christmas cactus to drop its buds, as will insufficient water.
Ethylene gas seems to affect the buds of the Christmas cactus.
Chilling or exposure to cold drafts may be a second cause. Thelack of sufficient potash in the soil will also bring this about.
Water your plant sparingly, and feed plants weekly with a diluted liquid houseplant fertilizer from the time the buds begin to appear until they open.
Give your plant less water than usual from early October until buds show. That may solve the problem.
After flowering is passed, rest by withholding feeding and applying just enough water to prevent soil from drying out, though a similar rest period is needed in the fall and early winter before flower buds develop.
The best winter-time temperature ranges from 60°-70° degrees Fahrenheit, during the day, with a drop to 50°-60°degrees Fahrenheit at night.