The term "crepe murder" is often thrown around when the subject is pruning crepe myrtles (Lagerstroemia indica), but don't let that make you think you can't cut the summer-flowering beauty. Crepe myrtle, which grows in U.S. Department of Agriculture plant hardiness zones 7 through 9, stands up to virtually anything a blade can do -- whether accidental or on purpose -- and grows back to bloom again.
About Crepe Myrtle
Crepe myrtle grows as a multistem shrub or can be trained into a small vase-shaped tree with several trunks or even a single-trunk standard. The plant grows 10 to 30 feet tall, depending on cultivar. Crepe myrtle grows in full sun in a range of soil types as long as it is well drained. The tree gets its name from the crinkled, crepe-paper texture of the flowers, which may be red, pink, purple or white.
In general, pruning spurs new growth and new flowers on plants that bloom on new wood, like crepe myrtle. This bit of plant biology leads many gardeners to cut back their crape myrtles to a certain height each year -- often the same height each year -- in an effort to get the most blooms from their trees. It sounds sensible, but experts dub this practice "crepe murder," because its result is ugly stubs that do grow plenty of flowers, but on spindly stems that often collapse under their weight. The practice also saps the strength of the plant.
Crepe myrtles can take most any level of pruning, from removing just the spent flower clusters to cutting the entire shrub back near to the ground, according to the U.S. Forest Service. The recommended method of pruning thins rather than shortens individual branches and uses sharp, sterile pruning tools. Removing shoots coming up from the base of the shrub, congested growth and upper branches growing toward the center of the tree can still keep your crepe myrtle from growing too tall. The branches send out fresh shoots to keep the flowers coming, though even older branches keep sending up new blooming shoots.
When your crepe myrtle gets chopped, it responds by sending numerous shoots up from the ground. To retrain the plant, choose the strongest three to five shoots that are evenly spaced and cut the rest to the ground, advises "Southern Living's" Grumpy Gardener, Steve Bender. Each year, just remove additional shoots at ground level and any shoots and branches lower than the bottom 4 feet of your new main trunks or that grow in toward the center of your new, naturally shaped crepe myrtles.