How to Grow Rose Geranium

Rose geranium is the common name given to both Pelargonium graveolens and Pelargonium capitatum, two species of scented-leaved geraniums characterized by attractive pink and white blooms and rose-scented foliage. Care is the same for both species. Rose geraniums are often grown as annuals, though they may be grown as perennials in U.S. Department of Agriculture plant hardiness zones 10 and 11. These versatile plants offer spring and summer color to the garden with moderate maintenance and care.

Rose geranium prefers a bright, sunny location, ideally with some light shade in the afternoon.

If growing multiple geraniums, provide 12 to 24 inches of space between plants.

Where not hardy, rose geranium may be grown as an annual or it may be kept indoors as a houseplant in front of a sunny, cool window. You can also coax the plant into dormancy by moving the plant indoors before the first frosts of fall and keeping it in a cool, dark, frost-free area indoors until temperatures warm up in spring.

Rose geraniums are heavy feeders that prefer well-draining, rich soil. You can increase drainage by tilling 2 to 3 inches of organic matter, such as leaf compost or shredded bark, into the top 6 to 8 inches of the soil with a tiller or garden spade.

Before planting, mix 2 cups of a dry 10-10-10 fertilizer, or 4 cups of a 5-10-5 fertilizer, per 50 square feet into the upper 6 inches of soil. Water well to incorporate into the soil. Alternatively, you can fertilize every three weeks during the growing season, from late spring until early fall, with 2 tablespoons of a water-soluble 20-20-20 fertilizer diluted in 1 gallon of water. Do not use both methods. For perennial geraniums, continue to fertilize every three weeks the following year during the growing season, starting when spring frosts finish.

Indoor plants should be planted in a good quality potting mix, in a container with a hole in the bottom for drainage. Fertilize two or three months after planting with 1 teaspoon of a 20-20-20 fertilizer mixed in 1 gallon of water. Repeat every four to six weeks during the growing season.

Store unused fertilizer in a secure location away from children and pets.

Irrigate regularly during the growing season, but allow the soil to dry out somewhat between waterings. Soil should not be allowed to become completely bone dry. If the plant develops wilted or yellow leaves, water more often. Mulch with 2 to 3 inches of organic material to maintain consistent moisture and keep soil cool. Avoid splashing the leaves with water, as this encourages foliar disease. Containerized plants should be watered until water drains out the bottom. If you're using a saucer under the pot to collect water, dump water out after a few minutes.

Remove dry foliage and spent flowers as they appear to keep the plant looking tidy, and to prevent Botrytis fungus. Removing dead flowers and pinching back stems will also help prolong flowering. Pruning is not necessary for outdoor plants, though pruning or pinching back indoor plants may be desirable to create a more compact plant. Always use sterilized pruning tool blades to keep from transferring disease to healthy plants. Wipe the blades off with alcohol and allow them to dry before pruning.

Check foliage and flower buds for aphids and white flies, small sap-sucking insects that are particularly fond of indoor geraniums. Dislodge pests with a direct stream of water, or mix 2 1/2 to 5 tablespoons of horticultural oil per 1 gallon of water and spray the entire plant, including leaf undersides, with a hose end or handheld sprayer. Store unused oil out of direct sunlight in a secure location; do not store with food products.