August Shrub of the Month-Crape myrtle

It happens every summer. I get emails or phone calls asking, “What’s that big bush with the pink flowers on the corner of….” The reaction is usually surprise when I say it’s a crape myrtle, Lagerstroemia indica. Better known in the South, crepe myrtles grow into beautiful small trees- no proper southern garden is without one…or more.  

Unfortunately, in St. Louis, our winters are a bit too harsh for them to mature into real trees. Mother Nature tricks us some years with a mild winter, but just when you think you’ll have a REAL crape myrtle tree to brag about, we get a cold winter that reduces it to an upright pile of dead sticks, or even worse, a half-dead bunch of sticks.

The flowers are worth all the trouble. Crepe-paper-like inflorescences usually come in shades of red, purple, or white and look stunning after everything else in the garden is starting to look worn. The long-lasting flowers are showy from July-September in St. Louis.

Height varies according to cultivar. Some have a more dwarf, rounded shrub habit. Others can be thinned down to 3-5 stems to resemble a small tree growing to 10+’ in one season. Crape myrtles prefer full sun and not too fertile soils.

Cultivars;

-‘Natchez’- A cross between L. indica and L. fauriei. White flowers and powdery mildew-resistant foliage. More tree-like form. 4-21′ high.

-‘Zuni’-lavender/purple cultivar with improved hardiness and resistance to powdery mildew. 8-10′

-‘Whit II’ DYNAMITE-Red blooms and powdery mildew-resistant foliage. More tree-like growing 5-20′. 

What I love about this plant

-It’s an absolute showstopper when in bloom.

-Foliage can have decent fall color, and some cultivars have reddish/purple leaves all season.

-Great late-season, long-lasting blooms in multiple colors, usually reds, purples, or white.

-Can grow 4-8′ tall in one season depending on cultivar.

-Flowers on new/current year’s wood and blooms reliably even if cut down to ground level.

-Showy seed capsules that persist through winter and beautiful bark.

What’s not so great

-They can be killed down to the ground at least every few years with harsh winter temps. Don’t be fooled into thinking you’re getting a tree. Mulch heavy for winter protection of the root system. A sheltered, yet sunny location can be helpful.

-Prone to leaf spot and powdery mildew.

-They are one of the last plants to break dormancy in the spring and fool many people into thinking they are dead. Wait until you see the leaves emerge before hacking it off or pitching it. The emerging leaves tell you exactly where to trim it down like you would a butterfly bush, or save yourself the trouble and trim it to ground level every year. 

Words and photos by Jo Batzer

© Jo Batzer, garden-lou.com, All rights reserved.