Crepe Myrtles

Written By Danny Lipford

About Crape Myrtles

With literally hundreds of sizes and colors available, crape (or crepe) myrtles are a terrific, low-maintenance choice for prolific blooms during hot, humid summers. Nowadays, many varieties are hybrids that maximize the colorful blooms of the common crape myrtle (Lagerstroemia indica) and/or the distinctive bark, cold hardiness, and disease-resistance of the Japanese crape myrtle (Lagerstroemia faurei).

Crape myrtles bloom in midsummer, with colors including white, lavender, purple, pink, magenta, and red. After blooming, they develop distinctive seed heads, then the leaves tend to fall toward the end of autumn, leaving the colorful, exfoliating bark for the winter.

Selecting Crape Myrtles

Crape Myrtles truly come in every possible size and shape, from knee-high shrubby dwarf plants to towering tree forms, so it is possible to choose a variety that exactly fits your purpose. When choosing crape myrtles for your yard, there are several factors to consider including:

• Height
• Natural shape (shrub vs. tree)
• Flower color
• Amount of bark exfoliation
• Disease resistance

Planting Crape Myrtles

Ideally, crape myrtles should be planted in cool weather when they’re dormant, here’s how to go about it:

• Dig Hole: Dig a hole twice the size of the root ball on the crape myrtle.
• Soil amendments: It’s usually not necessary to amend the soil when planting crape myrtles, unless you’re amending the entire planting bed, since pockets of high-nutrient soil can prevent the roots from branching out properly.
• Planting Depth: Plant your crape myrtle at the same depth it was in the nursery pot, and backfill with loosened soil.
• Mulch: Apply 3″- 5″ of mulcharound the base of your crape myrtle.
• Watering: Water your newly planted crape myrtle thoroughly after planting. Water newly planted crape myrtles at least once a week if dormant and in cool weather, and up to five times a week if planted during hot weather or in very sandy soil. Water new plants regularly for about two months, and water during drought for better blooms and healthier plants.

Growing Crape Myrtles

Crape myrtles can be grown in much of the U.S., except colder climates in the north. Here’s what you need to know to grow crape myrtles in your yard:

• Climate: Crape myrtles can be grown in hardiness zones 6-10, although in zone 6 they’re likely to die back to the ground in winter.
• Water: Crape myrtles like humid climates. Once established, they can tolerate quite a bit of drought.
• Light: Crape myrtles flower best in full sun (at least six hours per day).
• Soil: Crape myrtles do well in most any kind of soil, as long as it’s well-drained. The ideal soil pH is neutral to slightly acidic.
• Fertilizer: Crape myrtles benefit from annual feeding with a general-purpose or high-nitrogen fertilizer, in early spring as soon as you see leaves. If you want to fertilize twice, do the second application about two months later. Slow-release fertilizer can help prevent rapid sucker growth that is vulnerable to diseases and insects. Take advantage of the toughness of these plants – too much fertilization can actually result in excessive leaf growth and fewer blooms!

Pruning Crape Myrtles

Depending on the variety, crape myrtles can have different shapes and sizes. The miniature, or dwarf, varieties are generally bred to have lots of branches, and they tend to look shrublike and shouldn’t need pruning unless they are growing unevenly.

Medium and large varieties tend to develop sucker growth, or small shoots at the base of the trunk. These may be pruned off if desired, and the entire plant may be pruned according to your tastes. For varieties that bloom before mid-July, deadheading can often result in a second blooming.

• When to Prune: Crape myrtles bloom on this year’s new growth (sometimes called “new wood”), so prune during late winter before growth starts. Fall pruning, especially in warm climates, can result in a quick growth response that prevents dormancy and makes winter freezes potentially deadly.
• How to Prune: There are two schools of thought, and quite a bit of debate, about larger pruning jobs. Some gardeners like to lop off all stems at a uniform height each year, leaving branch stubs in the winter that flush out into a ball of growth in the spring. This is useful if you want a uniform border and height control, but it can result in bunchy growth and knobby stems that may be more susceptible to aphids and disease. Other gardeners decry this method as “crape murder” and adopt a less aggressive approach that conforms more to the natural size and shape of the plant. Most growers and researchers agree that only light pruning is necessary for plenty of blooms, so the choice is really yours.

To achieve a graceful tree shape that shows off the lovely bark, first remove all but 3-5 strong trunks. Then remove lateral branches on the bottom half of the tree. Make “heading back” cuts on long, leggy limbs to encourage branching. Don’t over prune in the beginning – make the basic cuts and then allow the plant to grow, and continue shaping over time.

The best decision about the size of your crape myrtle is made when you buy it. Buy the right variety to fit the space! If you buy a 15′ variety and try to keep it 7′ tall, you will prune yourself silly. Instead, buy a 7′ variety, and you will find yourself with an incredibly low-maintenance plant.

Pests and Diseases for Crape Myrtles

Crepe myrtles are susceptible to several diseases and pests, including:

• Powdery Mildew: The most common scourge of crape myrtles is powdery mildew – particularly during hot, humid days followed by cool, dewy nights. Treat with a general fungicide.
• Sooty Mold: This is caused by the excretions of pests such as aphids. Treat with the appropriate insecticide.
• Leaf Spot: Another common problem is leaf spot (Cercospora lythracearum), which resembles dark brown spots on the leaves that then turn yellow and fall off. Treat with a general fungicide.
• Root Rot: Crape myrtles can also be affected by root rot, caused by poorly-draining soil.

For more information and instructions please contact Deltona Garden Club