Q We have a large Kalanchoe, which bloomed profusely for almost a year. It has been in a bright window, but now it doesn't bloom at all and hasn't bloomed for quite some time. Is there anything I can do to get the clusters of red blossoms to come on again?
Like poinsettias, Kalanchoe plants are photoperiodic. This means they need a certain day length to initiate flower bud formation. Once they start blooming, they may remain in flower for several months, if spent blooms are removed promptly. Commercial growers have automatic shades or curtains that shut out light at the proper time and open on schedule in the morning.
You can move your plant to a closet each night if it is easier than covering it with a black cloth. If you shade it from 5 p.m. until 8 a.m. the next morning for six weeks, beginning July 15 until Sept. 15, it will bloom about Oct. 15. Plants shaded from Aug. 15 to Oct. 15 will bloom the first part of December. If shaded from Sept. 1 to Oct. 20, they will be in bloom for the Christmas holidays.
Keep in mind that preferred night temperature is 60 degrees F. when buds are forming, reduced to 50 degrees F. night temperature as soon as buds begin to show. Not having the proper temperature will offset flowering dates, but they should bloom eventually.
If you have a question about your garden, inside or out, send it, along with a self-addressed, stamped envelope, to the Garden Page, The Christian Science Monitor, One Norway St., Boston, MA 02115.
Doc and Katy Abraham are nationally known horticulturists.