Those beautiful crape myrtles are in bloom again. The many varieties bloom at different times and provide magnificent color almost to our first frost. But, is it ”crape” or “crepe” myrtle? I guess it depends on how your parents or grandparents spelled it. For a master gardener like me, Clemson makes the call. The information that they provide on their HGIC website (http://www.clemson.edu/extension/hgic) calls them “crape” myrtles. The American Crape Myrtle Society uses an “a” rather than an “e” and they are the authority on the subject. I did find several websites with crepe used, but I’m sticking with crape until Clemson changes it. You also have to decide if you want to split the name “crape myrtle” or run the two words together as “crapemyrtle”. My word processer kept highlighting crapemyrtle as a misspelled word so who am I to argue with a computer?
Crape myrtles are members of the genus Lagerstroemia and have close to fifty different species of varying sizes and colors. They also come from a variety of locations in Asia with the largest number originating in China. Some varieties are classified as trees. Carolina Beauty can reach 25 to 30 feet with spectacular red flowers. If you like your plants small, no problem! There are varieties that will grow in containers or cascade over low walls like groundcovers. Most varieties have multiple trunks that mature into tree form with outstanding bark. This is a very versatile plant!
Before we get into the various sizes and colors, let’s discuss some of the things that are critical to growing great crape myrtles. It all starts with full sun and great soil. This can be a problem in Aiken. We certainly have the sun although if you are planting a new crape myrtle in a mature landscape, be sure that your new plant will not be shaded by other large trees or shrubs. Crape Myrtles want to be in full sun coming from all directions. We have many “half and half” crapes in Aiken. A “half and half” crape gets sun on one side and shade on the other. This results in flowers in the sun and green leaves in the shade. Soil is our next concern. Crapes like a slightly acidic soil with a pH of between 5.0 and 6.5. Although they do not require a lot of fertilizer, a 10-10-10 slow release product will be appreciated. I will usually amend the sandy soil with compost when I plant a new crape myrtle making sure that the root ball has been loosened to allow the roots to easily find a new home.
One of the forgotten benefits of crape myrtles is their fall display. The flowers will be gone but the cool weather brings out their colorful foliage. You will be pleased to see brilliant red, yellow and orange in your landscape until the frost causes the leaves to drop. Re-blooming is possible but the second display is not nearly as good as the first. To promote a second bloom, remove the first bloom that is in decline. The theory is that the plant will energize a second bloom and give you additional color until the first frost. I have never had great success with this approach but it may be worth a try.
Most varieties, especially newer ones, will not get powdery mildew. In extreme cases, entire twigs may be blighted by the mildew fungus. While this fungus disease will not kill affected crape myrtles, blighted foliage detracts from the appearance of a popular Southern landscape plant. Leaves infected early in the season by the powdery mildew fungus become curled and distorted as they expand. Infected younger leaves have blister-like areas which quickly become covered with the mildew. On older leaves, large white patches of fungus growth appear, but there is little leaf distortion. Flowers which originate from infected buds often become blighted. You can help prevent powdery mildew by using a preventative rate fungicide prior to leaf-out. There are many effective fungicides available. Be sure to read the label and follow instructions carefully. It will probably call for a second application within two to three weeks. A light horticultural oil is also effective in cool weather but dangerous in temperatures over 85 degrees.
Crape myrtles will also draw crape myrtle aphids to their leaves. These are light green insects that suck the liquids out of the leaves. The leaves will change to a very light green before turning brown. An easy way to get rid of them is to spray them with a strong stream of water. Insecticidal soap is also effective.
And now, we reach the most exciting part of the discussion. Should we prune and, if so, do we use the gentle method or do we chop it to shreds? It’s obvious that both methods are used in Aiken. There is a third method and this one is the best. Just leave the plant alone. If you made the correct choice in the first place, a crape myrtle will do fine on its own. As mentioned earlier, there are crape myrtles for every location. In a wide open setting, plant a tree form that might reach 25-30’. Carolina Beauty, Natchez or Red Rocket are a few of your choices. Under second floor windows, you may be restricted to 10’-15’. Try Tonto or White Chocolate. For the very low restrictions Cherry or Raspberry Dazzle and Pixie White will grow to about 3-5’. Don’t forget Chickasaw and Pocomoke for containers. You can find a great selection guide showing sizes, shapes and colors at http://www.usna.usda.gov/PhotoGallery/CrapemyrtleGallery/CrapeTable.html.
The Master Gardeners will be at the Farmers Market on Saturday, July 7th from 8:00 A.M. until noon to answer your gardening questions. The next Lunchbox Lecture will be held at Trinity UMC on Monday, July 16th, at noon. The topic will be “Chemical Safety and IPM (what you don’t know can hurt you)” by George Montgomery, Master Gardener.