Nothing says summer in the South like the fresh, airy blooms of crape myrtles. From the pinks, the reds, the purple and the whites, they come in a rainbow of colors. They never fade, no matter how hot it gets. Throughout the Central Louisiana and the South, they seem to be everywhere — in every yard, parking lot and commercial landscape. Even with afternoon showers, their beauty remains. They thrive in the hottest of summers but cannot survive winter much farther north than Arkansas.
Crape myrtles (Lagerstroemia indica
) are essentially trouble-free plants. The crape myrtle was introduced to the southern United States more than 150 years ago. Sometimes called the "Lilac of the South," it has become associated in this country with southern gardens.Planting
Crape myrtles have a shallow, fibrous root system and are long lived. For best performance, plant in a sunny location that has good air circulation and a well-drained soil. In partial shade, flowering will be reduced and plants are more susceptible to leaf spot disease. Dig a planting hole for crape myrtles twice as wide and the same depth as the original root ball. For best results, plant during the dormant season, and use container-grown plants. Water deeply to encourage good root system establishment into the surrounding native soil. Mulches help crape myrtle performance. Pine straw is a great mulch that conserves soil moisture, decreases weed pressure, protects against weedeaters and is aesthetically pleasing.Fertilization
Follow soil sample recommendations. Generally, crape myrtles benefit from an annual application of 8-8-8, 13-13-13 or a slow-release fertilizer. Apply in early spring. Pruning
One of the best features of crape myrtles is the natural growth habit. Frequently, improper pruning destroys this desirable aspect. Use a selective method of pruning (thinning out the plant canopy) to achieve the best growth habit. Also remove any weak, crowded limbs in the center of the plant canopy to provide an open growth habit that allows air circulation and sunlight penetration.Failure to Flower
One of the problems occasionally encountered is the lack of flowers. Possible reasons for lack of flowering include:
Insects and Diseases
- Excessive shade. Crape myrtles require 8 hours of full sun daily for optimum flowering.
- Variety. Some varieties don’t flower as vigorously as others.
- Heavy aphid infestation. Aphids are common insect feeders on crape myrtles and can decrease flowering.
- Lack of fertilization. Crape myrtles require fertilization for new growth. If new growth doesn’t occur in the spring (because of nutrient depletion or cold weather), flowering may be greatly reduced.
- Improper pruning. Drastic pruning or pruning after new growth in the spring can delay summer flowering. Drastic pruning may promote excessive growth and less flowering.
- Overfertilization. Excessive fertilization in conjunction with other factors, primarily improper pruning, can eliminate or delay flowering.
- Leaf spot. Foliar diseases decrease plant vigor and flowering, especially where new growth is not produced in the spring.
Major diseases found on crape myrtles in Louisiana are powdery mildew and Cercospora leaf spot.
More information on varieties and care of crape myrtles is in LSU AgCenter publication 1466
or contact your local county agent