Lagerstroemia

A 4 m (12 ft) crape myrtle in Lutherville, Maryland

Red Rocket crape myrtle

Crape myrtles are chiefly known for their colorful and long-lasting flowers which occur in summer. Most species of Lagerstroemia have sinewy, fluted stems and branches with a mottled appearance that arises from having bark that sheds throughout the year. The leaves are opposite and simple, with entire margins, and vary from 5–20 cm (2–8 in). While all species are woody in nature, they can range in height from over 30 m (100 ft) to under 30 cm (1 ft); most, however, are small to medium multiple-trunked trees and shrubs. The leaves of temperate species provide autumn color.

Flowers are borne in summer and autumn in panicles of crinkled flowers with a crêpe-like texture. Colors vary from deep purple to red to white, with almost every shade in between. Although no blue-flowered varieties exist, the flowers trend toward the blue end of the spectrum with no orange or yellow except in stamens and pistils. The fruit is a capsule, green and succulent at first, then ripening to dark brown or black dryness. It splits along six or seven lines, producing teeth much like those of the calyx, and releases numerous, small, winged seeds.

In their respective climates, both subtropical and tropical species are common in domestic and commercial landscapes. The timber of some species has been used to manufacture bridges, furniture, and railway sleepers,[5] but in Vietnam's Cát Tiên National Park, the dominant stands of Lagerstroemia calyculata in secondary forest are thought to have survived (after episodes of logging) due to the low quality of wood.[6] Lagerstroemia species are used as food plants by the larvae of some Lepidoptera (moth and butterfly) species including Endoclita malabaricus.

The leaves of L. parviflora are fed on by the Antheraea paphia moth which produces the tassar silk, a form of wild silk of commercial importance in India.[7]

L. microcarpa leaves

Certain species of crape myrtle are used in landscaping and gardening as screens, lawn specimens, shrub borders, and container plants. Since crape myrtles are found in many places, there are differing opinions as to how to cultivate them in landscaping. Crape myrtles are best cultivated in warmer southern climates zone 7-9 and prefer full sun. They come in a variety of flowering colors and size.

Each year, the crape myrtles are often cut back ostensibly to allow for new growth over the next season, often referred to as crape murder. However, this notion that only new growth bear flowers is false though new growth does produce more flowers than established growth. Crape myrtles can at times be pruned in order to help shape the tree and get rid of unwanted or unsightly growth.

Cutting crape myrtles back too far can be detrimental because it prevents the trees from forming beautiful, mottled bark on mature trunks. It also creates a forest of skinny, whip-like shoots sprouts from the end of each ugly stump that remained from the last season. These whips are too weak to hold up the flowers, so the branches often bend to the ground.

Crape myrtles are relatively friendly to foundations and walkways in that the roots are not strong nor damaging to fixed structures, they form large networks of fine fibrous roots, rather than large heavy penetrating surface or tap roots. The root zones however can be very competitive for water and nutrients when considering growing other plants under the tree's canopy.

Crape myrtles are quite messy, and their seedpods stain concrete and are best planted away from swimming pools, decks and sidewalks.

• 
  Crape myrtle during summer in Sombrerete, Mexico
• 
  Same tree during fall

L. indica flower and flower buds

A Hot Pink crape myrtle in Oklahoma

The common crape myrtle (L. indica) from China and Korea was introduced circa 1790 to Charleston, South Carolina, in the United States by the French botanist André Michaux. In the wild, the species is most often found as a multistemmed large shrub, but 200 years of cultivation have resulted in a huge number of cultivars of widely varying characteristics. Today, crape myrtle varieties can fill every landscape need, from tidy street trees to dense barrier hedges to fast-growing dwarf types of less than 60 cm (2 ft), which can go from seed to bloom in a season (allowing gardeners in places where the plant is not winter-hardy to still enjoy the intense colors of the frilly flowers). In Europe, crape myrtle is common in the south of France, the Iberian Peninsula, and most of Italy; in the United States, it is an iconic plant of gardens across the southern United States.[8]

While not as widely known, the Japanese crape myrtle, L. fauriei, from central and southern Japan, is becoming increasingly important, both as a landscaping plant and as a parent in complex hybrids with L. indica. This species is distinctly tree-like, with colorful deciduous bark and dark green leaves which are more resistant to fungal diseases than are those of its more popular relative. The Japanese name for this tree is saru suberi (猿滑、百日紅, literally "monkey slip", latter spelling ateji) which refers to the smooth, slippery bark. Flowers are as large as those of L. indica, but are white with only the slightest pink flush appearing in some individuals. Japanese crape myrtle is hardier to cold than many strains of L. indica, a characteristic (along with fungal resistance, tree form and colorful bark) that makes it valuable as genetic material for hybridization. Cultivars available include 'Kiowa', 'Fantasy', and 'Townhouse'.[9]

Lagerstroemia speciosa, known as queen crape myrtle, giant crape myrtle, or banabá, originates in subtropical and tropical India. It can be grown in any similar climate, but in the United States is suitable only for Florida, southernmost Texas, South Louisiana, coastal southern California, and Hawaii. It is a large evergreen tree with colorful rosy-mauve flowers and striking white bark, suitable for public parks and avenues; only the seed-grown species is commonly available for sale, unlike L. indica and L. fauriei, which have dozens of cultivars.

Notes

Further reading

• "Lagerstroemia". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government.
• Flora, The Gardeners' Bible, ABC Publishing, Ultimo, NSW, Australia, 2006

Wikimedia Commons has media related to Lagerstroemia.

•  "Lagerstromia" . Collier's New Encyclopedia. 1921.