Geraniums, also known as Pelargoniums, grow natively in South Africa and require warm temperatures to survive. Because they are sensitive to both heat and cold, gardeners grow the plants as annuals in the United States. Popular as bedding and container plants, geraniums thrive during the spring and summer in most areas of the country. Growers value geranium plants for their colorful blossoms and attractive leaves. Flowers appear in shades of white, pink, purple and red, and the entire plant reaches up to 15 inches in height.
Plant geraniums during spring just after the final frost of the season. Choose a location that receives six to eight hours of direct sunlight each day or plant in partial shade in very hot climates. Space geraniums at least 12 inches apart.
Spread a 6-inch layer of mulch over the soil surrounding geraniums to insulate the soil, suppress weeds and slowly release nutrients throughout the year. Replenish the mulch as often as necessary to keep it 6 inches thick.
Water geraniums twice each week during the spring and summer, soaking the soil to a depth of 3 to 4 inches at each application. Reduce the frequency of watering to once every two weeks during fall until the plants begin to die back, and then cease watering.
Feed geraniums once per month throughout the growing season using a balanced 10-10-10 NPK fertilizer. Apply at the rate recommended by the manufacturer. Water both before and after applying to release the nutrients and prevent root injury.
Prolong blooming by removing faded and spent geranium flowers whenever possible. Pinch off the flowers as close to the stem as possible to minimize damage and encourage the formation of new blossoms in their place.