The geranium (Pelargonium) popularly grown as a houseplant or in flower gardens for its bright, colorful blooms is an annual plant. If brought indoors for winter or grown in frost-free areas, the common geranium may live longer than one year.
Geranium species number more than 200, most of which originated in South Africa. The common geranium plant typically grows to heights of 12 to 18 inches. Flower colors include white, pink, fuchsia, orange, red and purple.
If planted outdoors, geraniums should be placed 12 inches apart in slightly dry soil. Indoors, geranium plants should be kept near a sunny window. Soil should be allowed to dry between waterings. A monthly application of fertilizer is recommended. Removal of dead flowers and leaves promotes new flowering.
Although hardy, geraniums may suffer from infestations of aphids, caterpillars, mites, slugs and whiteflies. In addition, they are susceptible to bacterial leaf spot, botrytis blight, rust and oedema—or dropsy. Most of these can be controlled with insecticides, fungicides and reduced watering.