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Crape myrtles put on a flower show during the summer months

One of the most beautiful ornamental plants in the landscape is the crape myrtle. These plants bloom profusely during the summer months, in colors ranging from red and pink to lavender and white. They also require minimum maintenance, making them a great addition to any landscape.

Crape myrtles are very versatile. They can range in height from less than 3 feet to more than 20 feet, depending on cultivar, and they perform well in confined spaces, making them well-suited for small areas. They develop several main stems, and multi-trunk crape myrtles being preferable to single-stem plants.

The plants are long-lived, can tolerate dry conditions after becoming established, and are relatively free of disease and insect difficulties.

Crape myrtles grow under adverse soil conditions, but perform better if they're planted in soil that has been well prepared. As with other ornamental trees and shrubs, dig the initial hole twice the width of the root ball and no deeper than the top of the root ball. Fill in the hole with the backfill that was dug out, after removing rocks and other debris. Research has shown that organic matter amendments are not necessary when planting in individual holes.

Water the plants thoroughly once a week until they become established. After that, crape myrtles can tolerate extended dry spells, although supplemental watering will enhance flowering.

Avoid applications of fertilizers high in nitrogen - they cause the plant to produce less flowers and more vegetative growth susceptible to pests and, if fertilized in the fall, crape myrtles will be more vulnerable to cold damage. Light applications of fertilizers in spring and summer are all that is needed.

The most common pest on crape myrtles is powdery mildew. It appears as a white to grayish powder on the surfaces of leaves, flowers and new shoots. It is most frequently found when the plants are growing in shady, damp locations with poor air circulation.

To control the fungus, place plants in full sun and plant resistant varieties, such as Natchez, Muskogee, Sioux and Tuskegee. Chemical control of powdery mildew is difficult to achieve.

Sometimes, tiny insects called aphids infest the crape myrtles and secrete a sugary substance that causes black sooty mold. The aphids can be controlled by applying insecticidal soaps or summer horticultural oils.

Crape myrtle flowers on new growth of the season, so you can prune plants any time during the late winter or early spring before growth begins without losing flower buds. Pruning the crape myrtles allows for the development of an abundance of new shoots and flowers.

Do not prune in the early fall before frost. It will force new growth, preventing the plant from going dormant, which can lead to freeze damage. The best time to prune is in the winter months during dormancy. However, very little pruning is actually necessary. With minimal efforts, crape myrtles are a beautiful addition to the landscape.

Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at timothy.daly@gwinnettcounty.com.