The most common geraniums are pelargoniums. True geraniums are called geraniums or cranesbills.
Both geraniums and pelargonium are in the Geraniaceae family, but each is a different genus and with hundreds of species.
The cranesbill name comes from the fruit that develops after flowering; it resembles a beak. Cranesbills’ blooms are five equal petals, whereas the five petals of pelargoniums grow two petals in one direction and three in the other.
Cranesbills grow worldwide and go by the common names of Kashir white, dusky cranesbill or wild cranesbill.
Pelargoniums are woody-based, native to Africa and go by the name of Martha Washington pelargonium, regal geranium, common and garden geraniums, ivy germanium and scented geraniums.
Pelargoniums can be fancy and color-leafed, many have scented leaves.
Geranium leaves are rounded or kidney-shaped, lobed or deeply cut. The geranium plant can be upright or trailing.
References to geraniums in the remainder of this article include also pelargoniums.
Plant geraniums in full or light shade in well-drained soil. Geraniums do best in at least six hours of sun, the same as roses. While they prefer sun, they will flower with less sun, in the shade of tall trees.
Water only when the soil is dry and not by overhead spray. They do not like water on their leaves or blooms. Give the roots enough room to spread.
Geraniums will bloom from spring through fall. Pinch back the plants to encourage blooming through the summer and to reduce legginess.
Deer do not typically like geraniums but if they are planted near deer trails and the deer are hungry, they may eat them.
Move plants indoors before the first frost in cold-winter climates or take cuttings at that time for next year. Geraniums are easily propagated by cuttings. Cut 1½ inches of healthy stalk and put it in soil at the clump’s end where it can get 8 to 10 hours sun. Water the cutting weekly. Taking cuttings is the preferred method of geranium propagation. Seeds can be started indoors, but they will produce only a single flower that falls off easily.
Pests of geraniums are mostly the result of poor cultural practices. Overfertilization may bring aphids. Wash them off with water. Soil that is too moist can bring about leaf spot, rust, blight, mildew and edema. Additionally, over fertilization actually produces fewer buds on the geranium plant.
The public is welcome to learn more about plant and landscape watering at an irrigation class on Saturday, March 9 at 9 a.m. at the Veterans’ Memorial Building, 130 Placerville Drive in Placerville. This free, three-hour class will cover water preservation, home sprinklers and drip irrigation systems. Learn how to reduce your water bill.
Master Gardeners are available to answer home gardening questions Tuesday through Friday, 9 a.m. to noon, by calling 530-621-5512. Walk-ins are welcome at the office, located at 311 Fair Lane in Placerville.
For more information about the public education classes and activities, go to the Master Gardener Website at ucanr.edu/sites/EDC_Master_Gardeners/. Sign up to receive the online notices and e-newsletter at ucanr.edu/mgenews/. You can also find Master Gardeners on Facebook.