AMES, Iowa -- Geraniums have been a popular bedding plant for many years. Plants are commonly grown from cuttings. However, geraniums can also be grown from seeds. In addition, there are several methods for overwintering healthy, disease-free geraniums. Here are some tips from Iowa State University Extension and Outreach horticulturists on starting geraniums for summer planting.
When should I sow geranium seeds indoors?
Geraniums are relatively easy to grow from seeds. However, geranium seedlings are slow growing. Geranium seeds should be sown in early to mid-February to produce flowering plants for spring. Flowering occurs approximately 13 to 15 weeks after sowing. Suggested seed-grown geraniums for Iowa include cultivars in the Pinto, Maverick and Multibloom Series. (A series is a group of closely related cultivars with uniform characteristics, such as height, spread and flowering habit. Generally, the only characteristic that varies within a series is flower color.)
I have over-wintered several bare-root geraniums in paper bags. When should I cut back the plants and pot them up?
Remove the bare-root geraniums from their storage location and cut them back in mid-March. Prune out the shriveled, brown, dead material. Cut back to solid, green, live stem tissue. After pruning, pot up each plant and water thoroughly. Place the potted geraniums in a sunny window or under fluorescent lights. The plants should begin to leaf out in a few days. Bare-root geraniums that are pruned back and potted in mid-March should develop into healthy, attractive plants that can be planted outdoors in May.
I have over-wintered several geraniums as potted plants. The plants have gotten tall and lanky. When should I cut them back?
Cut back the geraniums in mid-March. Cut back the plants by one-half to two-thirds. Afterwards, place the plants in a sunny window or under fluorescent lights. The geraniums will begin to grow again within a few days and should develop into stocky, well-developed plants by May.
To learn more about horticulture through training and volunteer work, ask for information about the Iowa Master Gardener program at any county extension office.