In the Garden: Crape Myrtle
by Charles Kidder
Mid- and late-summer can be tough on gardeners. This year, we’ve already endured blistering temperatures and powerful storms. Spring blooms are long passed, and fall flowers such as asters and goldenrod are still weeks away. But one plant reliably brings summer color to Southern gardens, the crape myrtle. Even when their flowers are gone, some crape myrtle varieties develop attractive fall color. And with the colorful bark on many cultivars, the color display even extends into the winter.
First, let’s get some confusion on spelling out of the way. “Crape” is most commonly seen, which is supposedly an Anglicized version of “crepe,” and refers to the crinkled nature of the flower petals. Sometimes you will see the name as one word, crapemyrtle, but for no particular reason, I will go with two separate words. Either way, we are considering the genus Lagerstroemia, which comprises about fifty species, all indigenous to East Asia, Oceania and Australia.
The common Crape Myrtle (L. indica) is native to China and Korea, but has been grown in this country since the middle of the eighteenth century, first being introduced at plantations near Charleston. This species can get quite large, perhaps up to thirty feet or more, but usually with several trunks. Colors on crapes run the gamut from red, pink, lavender and purple to white, so you should always be able to find one that works with either your house color or garden scheme. Bark on this species is smooth, typically peeling to reveal a silvery-grayish surface, often mottled with shades of brown, yellow or green. Small plants that you see at the nursery may not wow you with their bark but will only get better with age.
Lagerstoemia indica in its various incarnations held sway in the South for two hundred years, but in the 1950s things began to change. A new species, Japanese Crape Myrtle (L. fauriei) was introduced to horticulture by Dr. John Creech of the United States National Arboretum. At first glance, this “new” crape myrtle did not appear to measure up to its established rival: Its flowers are always white, and only appear for two weeks in early June. But L. fauriei has a few winning traits. Perhaps the most conspicuous is its rich, coppery bark; even if the tree never flowered, it would still be worth growing for this alone. It is also less susceptible to the mildew that often disfigures the leaves of the Common Crape Myrtle. Finally, it is a hardier plant, able to withstand temperatures five to ten degrees colder than its cousin. Still, owing to its short bloom period, L. fauriei is hard to find in the marketplace, occasionally appearing at specialty nurseries in the guise of the cultivars ‘Townhouse’ and ‘Fantasy’.
Where the Japanese Crape Myrtle has really changed the landscape is through its hybridization with the common species. We can now enjoy many hybrids, largely thanks to the work of the National Arboretum, that have improved hardiness, disease-resistance and amazing bark, as well as the variety of flower color and long bloom period that gardeners expect. There are dozens of these hybrids; perhaps the best known is ‘Natchez’, with white flowers and bronzy bark.
In choosing your crape myrtle, picking the color may be the easy part. Even then, it’s probably best to see the plant in person if at all possible. Verbal descriptions, and even photographs, can’t always capture the nuances of different shades. The trickier part of choosing a crape is finding the right size. The straight species of L. indica and L. fauriei can both ultimately exceed thirty feet, but much breeding work has aimed for tidier plants. Many websites, such as those of Clemson and Auburn, list crape myrtles by size range, so you won’t waste time looking at plants that are larger—or smaller—than you need.
Many of the newer crape myrtle introductions are the so-called dwarfs or miniatures; some growers even claim they have developed ground-cover varieties. Take descriptions of size with a grain of salt, since they are trying to convince you that their plant stays small. But once they are established, crape myrtles can be whacked to the ground if they get too big. One major warning: avoid “Crape Murder,” the annual pruning of larger varieties to a stump each spring. Besides looking funny—unless you are European—it leads to a mess of lanky shoots that flop over from the weight of the flowers. Proper pruning of crapes is done to open up the center of the plant, allowing better air circulation and discouraging the growth of mildew. Try to do this before the offending branch gets too large, ideally with a diameter of less than half an inch. Also, remove the suckers that sprout from the base of the plant; crape myrtles look best with three to seven sturdy trunks.
The one necessity in crape myrtle culture is full sun. (Also a lot of heat, not something we have to worry about.) They survive in part shade, but will be lanky, mildew-prone plants that don’t flower well. Make sure they are well-watered for the first year or two, but after that they’re drought-tolerant. Other than some compost, additional fertilizing is not necessary and can actually lead to lush growth that is an invitation to pests. If your plant is attacked by mildew or aphids, it’s best to avoid use of heavy-duty chemicals that also kill off the beneficial critters.
On a personal note, I do see why people seek out the dwarf crapes; there’s something to be said for a tidy shrub that flowers from mid-summer to early fall. But if you pick the smaller cultivars, you’re going to be missing out on the great bark that graces the larger varieties. Check out the accompanying picture of a 50-year old Lagerstroemia fauriei, with a trunk two feet in diameter at the base!