The trees were named by Carl Linnaeus in honor of Swedish merchant Magnus von Lagerström, whose Far East traders provided the first specimens of crepe myrtles in Europe. Although von Lagerström never traveled to China himself, his name is forever associated with this tree of Asian heritage. Say "la-ger-STREEM-ee-a." They were brought to France by botanist André Michaux where they were very unhappy! Then he introduced them to South Carolina, and well, the rest is history!
Before you choose a crepe myrtle, do some research on the website of the United States National Arboretum to discover the cultivar that is perfect for you. Consider not just the color of the flowers but maybe most importantly, the ultimate size of the tree. Do you plan to prune and/or groom it every year? Will you be viewing it out a window, as you drive up, or while gardening in the yard? Will it be a hedge, a shrub, or part of a clump? An alleé, perhaps (pictured left is the Crepe Myrtle Alleé at the Dallas Arboretum)? Or do you envision a single, elegant specimen tree? Consider carefully what you want the tree to look and act like in five years. Lagerstroemia grow quickly, and you don't want it to get too big for its allotted spot, which leads to awkward pruning complications.
You may feel as if you're being asked to select a rental car; compact, full-size, dwarf or luxury? Lagerstroemia can even trained as a single-stemmed standard or as bonsai. Here is a helpful table from the University of Georgia including different pruning solutions. There is even a groundcover size crepe myrtle, L. 'Rosey Carpet'.
Plant crepe myrtles where they'll get plenty of full sun. Lack of adequate sun is a leading cause of Lagerstroemia which don't flower as well as they can.
The trunks of the tree at right are outside our rented house in Texas. This is a classic case of what not to do. This Lagerstoemia has such tangled stems and strangled roots that it barely blooms, illustrating that even "crepe murder" is better than nothing.
The image at right is one I took on one of our walks around the neighborhood. The term "crepe murder" refers to the common practice of chopping Lagerstroemia off 3-4 feet above the soil, as you might do with a butterfly bush. While this is the right way to care for a butterfly bush, it is a particularly unattractive and gruesome way to murder a crepe—please don't do this with crepe myrtles. When hacked off in this way, it's true, they do flower more heavily the following year.
But this "murder" must be repeated every year or two, and it means your crepe will never acheive its full potential of having lovely, graceful, sinewy trunks. Don't constantly deprive your Lagerstroemia of a proper growing season.
|"Consider all your options when confronted with a large, old crape* [sic] myrtle in a space meant for a different shaped tree or shrub. To create clearance under the canopy, limb up old trees that have spread their lower limbs where they interfere with people or cars. Limb up above the roofline of a single story home to clear obstruction of a window or door. Eliminate one of the major trunks if it is leaning too close to a building." recommends the South Carolina Master Gardener Training Manual.|
*Lagerstroemia are known as "crepe myrtle" or "crape myrtle" or even "crapemyrtle," allegedly because their petals are like the crinkled tissue of crepe fabric or crepe paper. However, if you look at the website of the United States National Arboretum, which introduced 29 named cultivars, they are called "crapemyrtles," and in McKinney Texas, which has a crepe myrtle festival every year, they are crape myrtles.
I know from my horrendous French classes that a crêpe is a very thin pancake. Dictionary.com says that crape is confused with crepe. But now everybody says "crape myrtle," and as you know, once one web site says a thing, it must be true! Never-the-less, I will call them crepe myrtles. Or better still, call them "la-ger-STREEM-ee-a."
Before about 1960, hybridizers were working with only the initial genes available in L indica, which was only suitable for USDA zones 7 and above. They got a boost in the 1960s with the addition of genetic material from L. fauriei, collected in Japan and Korea. This new species of Lagerstroemia proved to have greater cold-hardiness and was markedly less susceptible to powdery mildew. Hybrids of the two are available in a wide variety of bark colorations (which is an attractive winter feature), maroon or bronze foliage, and bicolored blossoms, as well as a huge variety of sizes, from container-sized to large, towering trees.
An example is L. 'Rhapsody in Pink', at right, which has crimson new growth and flower buds, dark wine-to-green foliage, and soft pink flowers from late June until frost. (Photo © Terry.) 'Rhapsody in Pink' is only possible becasuse the original germplasm from L. indica, supplied by Michaux in 1790, was augmented in 1960 with genetic material from L. fauriei. Most modern crepe myrtle varieties posess genes from both L. indica and L. fauriei, shown by the designation indica x fauriei.
At left are the winter trunks of L. 'Natchez', showing their attractive variegated pattern resulting from exfoliation of the bark. USNA calls this "cinnamon brown," which is as good a word as any. The blooms are a snowy white, and 'Natchez' is reliably mildew-resistant. Photo © mgarr.
With some cultivars of crepe myrtle, you may be able to produce a second and maybe even a third round of flowering if you trim the blossoms off once they have finished. If you can even reach the flowers, that is. If the flowers are too high to reach, the blossoms will ripen into attractive seeds. if they fall, these may produce offspring which may or may not look like the parent tree. I realize that's a lot of "mays" for one topic, but the behavior of hybrids from seeds is quite unpredictable, as you surely have noticed.
Some hybrids are marketed as "sterile" which should mean that their seeds are not fertile. You may wish to pot up the suckers which you prune from the shrub; those should be genetic clones of the parent plant. You may also propagate them by air-layering.
You may find your crepe myrtle showering you with blossoms, especially with a heavy rain. If you find this to be bothersome, do not plant them near where you park a car or have a pool! Some people enjoy this feature because their lawns change color. You also may discover aphids showering you with the "honeydew" they produce.
Leaving space around the branches and in the middle allows for air circulation to prevent mildew and insects.
If you prune, do so in late winter or early spring. Pruning too early in the fall may trigger the tree to try to produce new growth which will be damaged when cold tempertatures arrive, and pruning too late will not allow the flowers time to be produced.
Gardeners outside the South may wonder: can I grow a crepe myrtle in my garden? The good news is that since the introduction of indica x fauriei, there are now cultivars which are winter-hardy down to zone 6 and maybe even zone 5. Cold weather may kill the plant above the ground without killing the roots. You may never get a chance to prune your Lagerstroemia; the cold may do it for you! Experiment, and take mcicro-climates into your planning.
As I said above, crepe myrtles have very shallow root systems, so in colder areas, protect their tender roots with a thick layer of a iiving hardy ground cover. Mulch extra-heavily with compost, chopped leaves, straw or hay. Wrap tender bushes in burlap or bundle them in coats of straw or leaves. You can even surround Lagerstroemia with plastic bottles of water which will retain heat.
The best solution, if you can't reconcile yourself to one of the hardier Lagerstroemia cultivars, may be to choose one which is small enough to grow in a tub. If you are unable to insulate your tub sufficiently, perhaps you can truck it in and out of an unheated barn or garage. After getting established, crepe myrtles do tend to be drought-tolerant, but if you're pushing the zone envelope, you'll want to make sure it gets balanced fertilizer once a year and enough rainfall to keep it in tip-top shape.
photos not otherwise attributed are © Carrie Lamont.