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Express-News
Gardening Etc.
Sunday, July 28, 2002

Versatility and the Crape Myrtle Go Hand in Hand

As you drive around town there is a tree, shrub or groundcover that is quite noticeable because of the beautiful color and lavish blooms. This week's article from Bexar County Extension is about the very beautiful and versatile Crape myrtle.

The Crape myrtle has quite a history. It originated in Asia and has been grown in American gardens since Colonial times. Their drop-dead gorgeous summer color has made them a hallmark plant. This "Queen of the Summer Flowering Plants" graces historic neighborhoods of upscale southern cities along with long forgotten home sites in rural areas.

Crape myrtle refers to several Lagerstroemia species and hybrids that are deciduous shrubs or small trees with origins in China, Japan, and other parts of southeast Asia. Lagerstroemia indica has been cultivated there for centuries and was a favored tree of Chinese emperors. L. indica and L. fauriei now are the most widely grown cultivars.

The crape myrtle is one of the most rewarding of our small trees or large shrubs for the landscape. Its ability to grow under nearly every soil condition and long blooming period make it one of the most widely used and greatly admired ornamentals. The traditional Southern spelling is "Crepe" Myrtle because the delicate flowers resemble crepe paper. The universal spelling is "Crape."

The Crape myrtle was designated as the official Texas state shrub by the 75th Legislature in 1997. Also in 1997, Waxahachie was designated the "Crape Myrtle Capital" of Texas. San Antonio could easily be a close second. While driving in almost any area of our city, one can count hundreds of these trees/shrubs in just a small amount of time.

Crape myrtles come in a wide range of bloom, color, and diverse form that includes everything from tall, vertical trees to dwarf shrubs. They laugh at the summer heat and really "strut their stuff" in full sun-- the brighter, the better.

The flowering season begins in June and continues until fall. Each long cluster of flowers (panicle) is composed of hundreds of one to two inch, red, pink, white, lavender, or purple flowers. Some cultivars have bicolor flowers (with two colors on each petal) and other cultivars have panicles composed of a mix of flower colors. In the fall, the color show is accentuated with the deep green foliage turning a bronze color, which then eventually turns yellow, orange, or red, before falling. When the leaves fall, a living sculpture remains. The trunk has smooth bark varying in color from pale cream or light gray to dark cinnamon; from rich brown to bright orange. The branches possess an attractive, gnarled, or twisted character. The bark exfoliates in early spring to reveal new colorations.

For best results and minimum maintenance, choose a cultivar whose growth characteristics and ultimate size fit your intended landscape use. Misplacement in the landscape will require you to prune the crape myrtle constantly to keep it from outgrowing its place. Single or multi-trunked specimens are ideal for a sunny deck, terrace or entranced walkways. A multi-trunked plant can become a specimen plant in the garden or a dominant landscape feature.

Trees (over 20 feet) are excellent as accent trees at the front door, in a prime accent corner of the backyard, placed adjacent to the patio, or any other sunny spot where a summer-flowering tree is needed. Large shrubs (10 to 20 feet) or medium shrubs (5 to 10 feet) provide summer privacy when massed together, or they can be used as accent trees. Semi-dwarf (3 to 6 feet) crape myrtles make excellent accents in a shrub border when planted in groups. Dwarf types (less than 3 feet) are effective as groundcovers, perennial bedding plants, or container plants providing vivid, summer-flowering interest. They also look nice massed together in front of somewhat taller evergreen shrubs. Miniature weeping varieties are beautiful when used in hanging baskets.

Most crape myrtles are sold in nurseries as container-grown stock. Purchasing container-grown plants ensures the quickest recovery after planting. Look for healthy, vigorous plants and transport them home carefully. Try not to expose the flowers to winds. Crape myrtles transplant easily, and since they are blooming now, you have instant gratification! Newly planted crapes should be irrigated regularly for the first few weeks to aid in establishment.

Well-established plants are extremely drought tolerant. They will grow and thrive under adverse soil conditions year after year. Mulches are beneficial in retaining soil moisture and minimizing soil temperature fluctuations during the summer.

Young crape myrtles develop multiple stems. Depending on your landscape use, the smallest stems should be removed leaving one main stem for a single-trunk specimen or two to four main stems for a multi-trunked tree. "Suckers" or water sprouts may develop along the lower portions of main stems or from roots. These should be removed when utilizing crape myrtles as trees. Tip pruning to remove old flower clusters will promote recurrent blooming, but it is not practical for large plants or low maintenance landscapes. Dwarfs grow tall shoots periodically that must be removed to maintain the planting as a groundcover.

If pruning is necessary to improve plant shape or form, prune anytime after the leaves have fallen. If plants are pruned while they are dormant, then the branch structure is readily visible without the foliage. You can prune plants anytime during the late winter or early spring before growth begins without loss of flower buds. Crape myrtles will bloom on the season's new growth.

It has become a common, but uneducated practice to hack back or "top" crape myrtles. Surely you have noticed the ugly stubs in yards around town, in the winter time. This type of abuse is unhealthy for the plants, unnecessarily-spent human energy, and/or an unnecessary expense for the homeowner. A better method is to remove just the twiggy growth to direct the plant into a desired form. This will enhance the natural artistic form and highlight the striking bark.

With the proper cultivar selection, the Crape myrtle is one of the most pest-free landscape plants available. New powdery mildew-resistant cultivars have been introduced in recent years. Powdery-mildew is caused by the fungus, Erysiphe lagerstroemiae. It first appears as a whitish powder that spreads to the surface of leaves, stems, and flowers. It can disfigure plants if left unchecked. Fungicide sprays can help, but the best way to deal with fungus is not to have to deal with it at all. Crape myrtles should be planted in sunny locations allowing free air movement so that wet foliage dries quickly. Even in a mass planting, estimate the mature size and leave enough room in between each plant to allow for adequate circulation of air.

Crape myrtle aphids, Tinocallis kahawaluokalani, can be a pest on crape myrtles. They are pale yellow in color. The winged adults have black wings and black protuberances. They are primarily found on the undersides of leaves and are particularly fond of new growth. Aphids excrete a honeydew substance. This sugary solution promotes the growth of sooty mold fungi, Capnodium species. It appears as a black powdery coating on leaves and stems. Sooty mold usually causes little direct damage, but it can cut vigor by reducing photosynthesis in the leaves. Existing sooty mold on leaves will wear off the leaves through the action of sun, rain, and wind. Insecticidal soaps and horticultural oils for control of aphids will also help to loosen the sooty mold.

There are few other plants that offer as many ornamental qualities as the Crape myrtle. Thanks to all of the superior cultivars available today, there is a Crape myrtle for just about any conceivable use in the landscape. Their bark color and texture, form and shape, flowering capabilities, fall foliage color, and interesting seed pods make them attractive year round. For web information on the characteristics of Crape varieties to go: aggie-horticulture.tamu.edu/plantanswers/trees/crape_myrtle_varieties.html.

For more information on Crape myrtle varieties and descriptions visit: aggie-horticulture.tamu.edu/plantanswers/trees/crape.html.

This article was contributed by Diane Pfeil, Horticulture Associate-Texas Cooperative Extension-Bexar County. For more information, please call (210) 467-6575.

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