Prepared by Debbie Shaughnessy, HGIC Information Specialist, and Bob Polomski, Extension Consumer Horticulturist, Clemson University. (New 06/99. Images added 11/06.)
Crape myrtle (Lagerstroemia species) is a handsome, summer-flowering, deciduous small tree or shrub. It is a favorite among Southern gardeners because of its beauty and low maintenance. It has been called the lilac of the south. The most common species in the United States is Lagerstroemia indica. It is native to China and Korea but is naturalized in the Southeast. L. fauriei, native to Japan, is another species found in the United States. Hybrids of the two species generally result in excellent selections. Both species and their hybrids are adapted to all areas of South Carolina.
Crape myrtle flowers
J.S. Peterson @ USDA-NRCS PLANTS Database
Heights range from dwarf to semi-dwarf, medium and tall, depending on the cultivar. The height range is from 10 to 30 feet, and width range is 15 to 25 feet. Old specimens can reach 40 feet at maturity.
Crape myrtle grows at a moderate to fast rate, and has a moderate to long life span.
The crape myrtle is valued mainly for its long period of striking summer flowers. These showy flowers may be shades of white, pink, red or lavender. Bloom time varies, depending on the cultivar. Large clusters appear on the tips of new branches beginning in early summer and continue into fall. After flowers fade and fall from the tree, fruit remains in the form of small brown capsules. These fruit remain throughout the winter.
’Fantasy’ crape myrtle bark
Karen Russ, ©HGIC, Clemson Extension
The attractive, exfoliating bark peels away to expose a trunk which ranges in color from many handsome shades of brown to gray. This bark is especially noticeable in the winter months when the tree is leafless. When leaves are present, lower branches can be removed to show off the handsome bark.
Fall leaf color ranges from yellow to orange and red. Although the same plant may display leaves of several colors, the white-flowered types often have yellow fall color, and the pink and red flowered types show yellow, orange and red leaf color in the fall.
Crape myrtle is ideally suited for formal or informal design in the home landscape, street plantings and community plantings. It can be planted as a specimen or in groups, and looks attractive when underplanted with a ground cover; the dark green of the groundcover contrasts well with the handsome bark.
It adapts well to confined spaces, and is, therefore, well-suited for small areas close to sidewalks or parking lots, and can provide shade in deck and patio areas. The flowers of some selections, however, may stain car paint, and the honeydew drops from aphids on the plant may stick on cars or patio furniture. As cultivars are now available in a wide range of growth heights, certain selections can be used under utility lines without fear of interfering with these lines.
The plant typically develops several main stems. These multi-trunk crape myrtles are more desirable than single stem plants in landscape plantings.
The ideal planting site is in well-prepared, well-drained soil, with full sun exposure and good air circulation. Crape myrtles planted in partial or full shade will have reduced flowering and increased disease susceptibility.
The plant will tolerate slightly alkaline to acidic (5.0 to 6.5 pH) clay and other soil textures. Although it tolerates drought, it requires irrigation until it is well-established (approximately two years). This is especially true when it is planted in confined areas.
Heavy nitrogen applications cause the plants to flower less and produce shoot and leaf growth that may be subject to winter injury. Light applications of a complete fertilizer in spring and summer are adequate.
Severe pruning of crape myrtles has become a common practice to maintain shrub size. This ruins the natural, graceful effect of the plant. Many dwarf and semi-dwarf cultivars are now available, making it possible for the homeowner to have the desired plant size while maintaining the natural branching effect. For more information on the pruning of crape myrtle, refer to HGIC 1009, Crape Myrtle Pruning.
Powdery mildew is a common problem with crape myrtle. It is most common during spring and fall. Leaves and young shoots are heavily coated with a powdery, white mold, and may become distorted. Flower buds may not open. Locating the plant in full sun and providing good air circulation helps prevent powdery mildew, but the best approach is to choose resistant varieties.
Sooty mold is a black coating on leaves that results from a fungus growing on honeydew excretions made primarily by aphids. Plant vigor may be decreased because of the reduction of photosynthesis in the leaves due to shading.
The bark is thin and can be easily damaged by mechanical injury. Mulch around plants to prevent this problem. Vigorous, shallow roots may create problems for healthy growth of underlying plants. Use sturdy ground covers or shrubs to underplant.
For more information on crape myrtle problems, refer to HGIC 2002, Crape Myrtle Diseases & Insect Pests.
Many crape myrtles are hybrids of L. indica and L. fauriei, developed at the U.S. National Arboretum in Washington, D.C. These were bred for disease resistance, good flowering and attractive bark. (Disease resistance means that infections are few, do not progress very far or do not occur). Some of the selections resistant to powdery mildew include:
The following are considered somewhat resistant to powdery mildew:
Note: Chemical control of diseases and insects on large trees is usually not feasible since adequate coverage of the foliage with a pesticide cannot be achieved.
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This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.