With four basic types and more than 200 species, geraniums are available in just about every shape and size. The cultivation requirements for most of them are virtually identical. While they love the warm weather of the growing season, most geraniums will bloom merrily right up until the first light frost.
Things You’ll Need
- Organic compost
- 10-10-10 fertilizer
- Organic mulch (optional)
- Balanced, water-soluble 20-20-20 fertilizer
- Buy unblemished, healthy-looking geraniums with dark green leaves. The plants should have a compact appearance with no leggy stems, which indicate that they were grown in improper lighting conditions. If you see any pests on a plant, leave the store and shop elsewhere. Plan to set your geraniums out as soon as you can. If it isn’t possible to do so immediately, water them thoroughly and place them in the shade.
- Choose a fertile, well-draining spot in full sun for your geraniums. They require at least six hours of direct sun daily for best performance. If you live in a hot climate and experience daytime temperatures in excess of 90 degrees Fahrenheit, partial shade is your best option.
- Cultivate the garden soil to a depth of 4 to 6 inches. Spread a 1- to 2-inch layer of organic compost and cut it into the topsoil to about 2 to 4 inches deep. Apply 1 lb. of 10-10-10 fertilizer for every 100 feet of garden space and rake it into the soil.
- Plant your geraniums late in the afternoon or on an overcast day after all danger of frost has passed for your location. Position them at the same soil depth that they occupied in the growing containers. Space them about 8 to 12 inches apart. Water the bed thoroughly to evenly moisten the surface soil. Don’t overwater to the point of runoff.
- Apply a 1/2- to 1-inch layer of organic mulch to your geranium bed, if you wish. This will help to retain moisture and discourage weed growth. Don’t spread a deep layer because the stems of these plants rot easily.
- Water the plants when the soil is dry at a depth of 2 inches.
- Feed your geraniums a balanced, water-soluble 20-20-20 fertilizer once monthly throughout the growing season. Water it into the soil. Follow the packaging instructions carefully.
- Cut geranium blooms freely for your indoor arrangements. Deadhead the plants as soon as blooms fade to keep them looking tidy.
- Pinch long, spindly, rangy or unattractive stems back throughout the season to encourage full, compact growing habits.
Tips & Warnings
Readily available geranium types are common or zonal (Pelargonium x hortorum); scented (P. graveolens, tomentosum and others); ivy-leaf (P. peltatum); and Martha Washington or regal (P. x domesticum).