Plants in shady areas will bloom less and are more susceptible to disease. Regular watering is required for most geraniums. During dry periods, a deep soaking once a week is usually sufficient for bedding geraniums, while container plantings often require more frequent watering. If possible, avoid overhead watering because wet foliage encourages disease development. When unavoidable, overhead irrigation should be done in the morning hours which allows the foliage to quickly dry, reducing the potential for disease.
Geraniums respond well to regular fertilization.
During the growing season a dilute solution of a soluble fertilizer applied once a month should keep garden and container geraniums growing and looking healthy. There are several disease and insect pests common for geraniums. The best control for these problems is prevention by proper placement, maintenance, and early detection. Prepared by Cindy Haynes , Department of Horticulture Iowa State University , Ames, Iowa. This information subject to a usage policy .