Geraniums are a colorful and strongly scented plant that makes a good indoor houseplant as well as a bright, hardy addition to an outdoor garden. You can choose among a wide range of colors, whether you prefer single or double flowers, and if you need a creeping geranium or an upright type of plant.
Most geraniums prefer a sunny location with at least eight hours of sun each day. They should be planted in a nice garden spot that has well-drained, loose soil. Heavy or clay soils should be amended with peat, compost and mulch to help geraniums grow better.
Plant geraniums in the spring, but be sure all danger of frost has passed, as they won’t germinate or bloom until the soil temperature is above 60 degrees Fahrenheit. Geraniums are usually propagated through cuttings taken from older geranium plants. Start them indoors in a loose soilless mix like vermiculite or perlite, not transplanting outside until the geranium cuttings are well-rooted and strong.
Cuttings can be taken any time of year, but will root best in spring and summer. If you’re starting from seeds, sow them indoors in potting mix with 16-20 hours of light, and a soil temperature of about 75 degrees Fahrenheit.
In warm, sunny areas, the heat and light may be available naturally, but in more northern areas, you probably will need to use artificial lighting and heating. You can plant them outside when they are showing leaves.
Caring for Geraniums
Geraniums suffer quickly if over watered or over fertilized. Water them when the soil is dry to the touch, but not before. They will do better in dry soil than in soil that’s too wet. Whether indoors or outdoors, be sure the soil for geraniums is well drained, and that any containers are too.
Fertilize once at planting, with a 10-10-10 fertilizer, at a rate of about two pounds per 100 square feet. You can add another application of fertilizer in midsummer if needed.
Water after fertilizing to help it spread into the soil. Another tip for geranium care is to check over the flowers regularly, pinching off any faded blooms or dried-up leaves. This will help prevent pests and diseases from flourishing in the plants.
Geranium Pests & Diseases
Insects are usually not a problem for geraniums, as their strong, bitter scent keeps most bugs from bothering them. In fact, geraniums are sometimes used as border plantings around gardens simply for their bug-repellent ability. However, some diseases do attack geraniums under the right conditions.
Root rot can develop from overwatering, while leaf drop begins to happen if geraniums are allowed to go through cycles of wilt and heavy rain too often.
Botrytis fungus is a common enemy of geraniums, but you can avoid it by removing dead and faded flowers and leaves regularly, and specialized geranium fungicides are available to combat an infection if one starts.
With any disease, if it begins to affect your geraniums severely, prune back, cut off or remove any dead, dying and diseased areas of the plant to prevent the disease or fungus from spreading.
Want to learn more about growing geraniums?
Check out these Web sites chosen by us for more information on the subject:
Geraniums are highlighted in this issue of Horticulture and Home Pest News from Iowa State University.
Oregon State University covers How to Buy and Care for Geraniums