Q. Each year our beautiful orange clivia blooms outdoors in our shade garden, but the tops of the foliage are often yellow and brown. What causes this discoloration of the leaves?
Georgiana Flaherty, San Jose
A. The most likely cause, if the plants are otherwise healthy and blooming, is too much water. Clivia, a South African native plant, prefer to be just barely moist, grown in soil with excellent drainage. Check your irrigation and soil moisture to make sure they aren’t getting too much water.
Twice a year, clivias need a rest period — in winter before flowering and immediately after spring blooming. During those times of rest, you should stop fertilizing them and water should be dramatically reduced to once every three to four weeks. When new growth starts to appear, you can resume your weekly watering and monthly fertilizing schedule.
Older foliage on the plants also will turn yellow and die as the plants produce new leaves. In that case, the yellowing is normal and nothing to worry about.
Clivia thrive with benign neglect. They don’t like to have their roots disturbed, so they only need to be dug out and thinned every three to five years. They also bloom best when they are slightly overcrowded.