Common Name: crape myrtle
Type: Deciduous shrub
Family: Lythraceae
Zone: 5 to 9
Height: 1.00 to 3.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: June to September
Bloom Description: Purple
Sun: Full sun
Water: Medium
Maintenance: Medium
Flower: Showy
Tolerate: Drought, Clay Soil, Air Pollution
Culture
Best grown in average, medium moisture, well-drained soils in full sun. Does well in loamy, clay soils with good drainage. Benefits from a slow release fertilizer. Overly fertile soils tend to produce lush foliage growth at the expense of flowering with somewhat increased susceptibility to winter injury. Water roots deeply, particularly in dry spells, but avoid wetting the foliage. Plant in a protected location and apply a winter mulch. Growing crape myrtles in the St. Louis area can be tricky because the above ground branches often die to the ground in winter, particularly when temperatures dip below -5 degrees F. Above ground branches are considered to be winter hardy to USDA Zone 7, whereas roots are usually but not always hardy to USDA Zone 5. In the St. Louis area (Zone 5b to 6a), some gardeners prefer to grow these plants in somewhat the same manner as buddleias (butterfly bushes) by cutting all stems back to 8” in early spring each year. Roots will sprout new stems which typically grow 2-4’ tall (sometimes more) by the end of the growing season. Flowers appear on the new wood. It is also an option in St. Louis to grow these plants as woody shrubs by pruning them back to live wood in spring at the time new foliage begins to appear (in somewhat the same manner as with some shrub roses). With protection, top growth will survive some winters, but may still suffer significant injury or die to the ground in harsh winters.
Noteworthy Characteristics
Lagerstroemia is a genus of about 40 species of deciduous and evergreen shrubs and trees from warm-temperate to tropical areas of Asia to Australia. They are grown for their very showy, lovely summer to fall bloom. In warmer areas many can be grown as trees but in colder climates they may be killed to the ground but resprout from below ground to be grown more as shrubs.
Genus name honors Magnus von Lagerstroem (1691-1759), Swedish botanist, Director of the Swedish East Indies Company and friend of Linnaeus.
Common name is in reference to the crepe-papery inflorescences and the myrtle-like (Myrtus communis) features of the bark and foliage.
'Mardi Gras' is a miniature weeping variety (sometimes referred to as part of the Dixie Series) developed by horticulturist David Chopin of Scenery Hill, PA. It is a deciduous, densely branched, small shrub which grows upright but with branch ends weeping downward. Features dark green foliage and terminal, crepe-papery inflorescences (panicles) of purple flowers which bloom from late spring into fall. In the South, this miniature crape myrtle typically grows 2-3' tall. In St. Louis where winter injury is a problem, plants will grow smaller.
Problems
The two main disease problems of crape myrtles are fungal leaf spot and powdery mildew. Foliage may yellow (chlorosis) in alkaline soils. Some susceptibility to aphids and scale. Winter injury, particularly to top growth, may occur in USDA Zones 5 and 6.
'Mardi Gras' reportedly has good disease resistance.
Uses
This compact crape myrtle may be grouped or massed in borders or foundations. Also a good rock garden specimen. Perhaps best grown as a container plant for patios or other locations around the home.