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Crape myrtle tree: Beauties that can take the heat

September 2, 2011 |  9:27 am

Crape myrtle flower
The Dry Garden: crape myrtle trees

An artist friend of mine calls crape myrtles “living bouquets.” In the hottest weeks of summer, the man to whom we owe thanks for the white, pink, lavender and red bouquets now before us, often un-watered and somehow unwilted, is Donald Roy Egolf. From 1958 until his death in 1990, Egolf was a plant breeder at the U.S. National Arboretum in Washington, D.C. His contribution was so outstanding that this column, besides constituting the deepest of bows to those wonderful plants, bears the suggestion that we rename the crape myrtle the Egolf tree, or Egolfus donaldii, so as to take in many new compact and shrub forms.

This is only half in jest. The existing names are crying out for a makeover. In the 18th century, Linnaeus, the Swedish father of modern systematics, honored countryman Magnus von Lagerström by donning the crape myrtle genus Lagerstroemia. As more and more variations -- trees as well as woody shrubs -- were discovered in India, China, Japan and Australia (never Sweden), the genus grew.

Crape myrtle barkSomewhere along the line, the observation that the flowers had crepe-like texture led to the trees attaining the common American names "crepe myrtle," "crape myrtle" and "crapemyrtle." The one-word spelling, preferred by the National Arboretum, evidently came about because it’s not a true myrtle. Computer spell-check programs prevented that from catching on.

It’s no better when trying to explain crepe versus crape, a task that reduced the writer of an information sheet for the horticultural extension service Floridata to exclaim, “It's a common name and since there's no authority that manages common names for plants, you can spell (or call it) whatever you like!”

The crape myrtle became popular in spite of dowdy nomenclature because of exceptional mettle and formidable beauty. The early and most popular introduction to the U.S., Lagerstroemia indica, is notable for the streaked taupe- and sage-colored trunks, exceptionally hard and smooth wood, and blushing variety of flowers.

Those flowers! Drooping clusters, blameless and somehow cool in late summer glare. Describing them, the normally soft voice of Margaret Pooler, Egolf’s successor at the National Arboretum, became suddenly intense when she got to the “fantastic diversity from pinks to purples to red.”


  Yet susceptibility to mildew, which can deform those fantastic flowers, dogged the reputation of Lagerstoemia indica for more than a century. In the 1960s, it was part of what inspired Egolf to embark on what became an epic breeding program crossing indica with the Japanese species, Lagerstroemia fauriei.

“Fauriei gives the plants the mildew resistance,” Pooler said. After what Pooler can only guess were “tens of thousands” of experimental crosses, then successive testing by cooperating nurseries, a new generation of hardy crape myrtle cultivars was born. The National Arboretum introductions are immediately recognizable through tribal names such as Hopi, Arapaho and Muskogee.

Crape myrtle leaves“Lagerstroemia fauriei tend to be trees," Pooler said. "They’re big plants. Faurieis all have white flowers and they don’t rebloom.” By contrast, some indicas not only come in a rainbow of colors but also rebloom. Shortly after the flowers fall in September, a spectacular autumn leaf show begins. By the time leaves running the gamut from orange to deep burgundy have fallen, the crape myrtle will have given more than four months of spectacular color. (That colorful foliage pictured at right was photographed in Woodland Hills in a previous September.)

To the eyes of connoisseurs, however, bare-limbed winter might be the tree’s best season. When it comes to crape myrtle bark, whether it is the lighter sage tones of the indica or cinnamon color of the fauriei, for elegance of shedding and suppleness of underwood, the crape myrtle can rival its barky beauties manzanitas and madrone any day.

To Pooler, who oversees open-air trial grounds in the relatively wet climate of the mid-Atlantic, it comes as a surprise that Westerners prize crape myrtles for their drought tolerance. Some USDA maps don’t even show California as part of the plant’s growing range. Yet if you look where university extension programs and nurseries have embraced crape myrtles, you will find locales that are hot and often dry: Florida, Texas, Oklahoma, Arkansas and California. To the mind of Nicholas Staddon, director of new introductions for California’s Monrovia Nursery, these plants bring crucial late summer grace notes to regions that by late August and early September are deep red on the USDA drought monitor.

“As a general statement, Lagerstroemia need regular watering when they first start out,” Staddon said, “but it is absolutely amazing how drought tolerant they become when they’re larger.”

His recommendations for Southern California homeowners include the hybrid shrub or small tree Pecos  for pink blossoms, dark bark and maroon fall leaves; the indica cultivar Catawba for violet flowers and red-orange fall leaves; and hybrid Zuni for purple flowers and orange-red autumnal leaves. A favorite of his is the Oklahoma State University indica cultivar Centennial Spirit for a large shrub or tree because of its deep red, long-blossoming flowers.

For homeowners who have small spaces, are looking for low-growing shrubs or wish to grow crape myrtles in pots, Staddon also suggests the University of Georgia dwarf series  of Cherry Dazzle, Raspberry Dazzle and Snow Dazzle. 

The potential for partnering crape myrtles of different sizes (from ground cover to tree), of different flower colors (white to burgundy), different fall foliage (orange to crimson) and different bark types (green-gray to cinnamon) is so wide open as to defy planting suggestions. They work beautifully in Asian gardens but look ideal in a cottage garden. When artfully pruned, their grace as multilimbed open trees make them a Modernist’s dream. For a native plant lover like me, they partner perfectly with shrub and ground-cover cultivars of manzanita. Bees do browse, and Pooler noted a light scent.

Crape myrtle sun
In every instance, they are water-wise, so tough that city of Pasadena urban forester Darya Barar likes to use them in tough spots, such as a row of little tree wells along Fair Oaks Avenue, where a larger, arguably more beneficial shade tree simply wouldn’t fit. In this thankless situation, Barar’s succession of cleverly selected crape myrtles responds with a blushing bouquet of summer flowers and autumn foliage. (The photo above shows an unwatered tree after a week in which temperatures spiked above 100.)

In home settings, Barar and Staddon see crape myrtles as ideal candidates for patio plants. To get young trees established in the ground in the foothills, Barar recommends a drizzling hose running for 45 minutes once a week in dry season. Potted plants will need daily water outside of dormancy and periodic soaking when dormant; they will endure pots, but if you can, put them in the ground.

For those who do their own pruning, Clemson University has produced an excellent guide. This much is obvious to the National Arboretum’s Pooler: If your crape myrtle needs regular hacking, it’s in the wrong place. A perfect pruning maintenance regime would be doing nothing. Apart from the lightest clearing of dead growth and pruning of suckers if you want to preserve a more open or tree form, these generally slow-growing plants should not require regular work, or water. Most appreciate full sun.

If it comes to taking out a badly positioned or hopelessly mutilated crape myrtle, harvest it carefully, retaining the limbs in long sections. Even call a local carpenter. This is prized hardwood. Also expect the roots to resprout. While this can be a nuisance with grafted plants such as roses, the beauty with crape myrtles (largely propagated from cuttings, so have true-to-breed rootstock) is that they flower on new growth each season. This means that suckering roots from a felled tree will emerge as a clump of late summer flowers. According to Pooler, in cold regions where crape myrtles can’t survive the frost but roots do live in mulched beds, gardeners use them as annuals.

Crape myrtle white Los Angeles County Arboretum and Botanic Garden horticulturist Frank McDonough mans the county’s help line for troubled gardeners. Many of the problems that he hears about with crape myrtles, he said, concern mildew on indicas set in lawn and inundated by sprinklers. Another common insult, he said, is weed whacking scars on trunks -- yet another reason to reduce or remove water hogging lawn and offer your neighbors hardy and beautiful flowering trees and shrubs instead. The funniest note from McDonough wasn’t about how we water crape myrtles but how they water us. If you’ve ever wondered where fine droplets came from on a clear sunny day in summer, look to your crape myrtle, he said. The “spitting,” he said, comes from the flowers. (That's the white crape myrtle Natchez, photographed last month in Jackson, N.C.)

Egolf’s obituary in the Washington Post records that after nearly 30 years of crossing crape myrtles, he produced 23 named cultivars. The idea -- Egolf’s idea -- behind the tribal series names, explained Pooler, was to identify them immediately as a product of the National Arboretum. It was pure gravy that these trees proved so durable in the dry West. So let’s keep the tribal names begun by Egolf and change the botanical and common ones. Here’s to the Egolf tree, whether it be a Comanche, Sioux or Cheyenne. In fact, from this fan out West, a request to the National Arboretum: How about an Egolf Gabrielino?

-- Emily Green

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Photo credits: Pink flower details and bark detail by Emily Green. Leaves by Los Angeles Times. White flower detail from Associated Press.

Green's column on low-water gardening appears here on Fridays. For an easy way to follow future installments, join our Facebook gardening page.

 

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