The crepe myrtle (Lagerstroemia indica) is a beloved ornamental tree or shrub prized for its vibrant, long-lasting summer flowers and attractive, often multi-trunked form. Cultivars range widely in size, from small shrubs to trees reaching 25 feet or more. Despite their popularity, widespread confusion regarding necessary annual maintenance often leads to improper practices that damage the tree’s natural structure and overall health.
The Myth of Annual Hard Pruning
Crepe myrtles should generally not be cut back severely every year, despite this being a common practice often termed “Crepe Murder.” This aggressive annual cutting involves arbitrarily chopping back large, mature branches to stubs or knuckles. This technique is typically performed to control the height of a plant that was originally placed in an inappropriate location for its mature size.
The negative consequences of this severe heading back are both aesthetic and biological. Repeatedly cutting the same branch location causes the formation of unsightly, swollen knots or “knuckles.” From these knuckles, new growth emerges as dense clusters of structurally weak, spindly shoots. These thin branches often droop unattractively, destroying the tree’s graceful, natural vase shape and are unable to support the weight of large flower clusters. Furthermore, the resulting dense, weak growth and open wounds increase the plant’s susceptibility to pests and diseases, such as powdery mildew.
Techniques for Healthy Maintenance Pruning
Instead of severe annual cuts, crepe myrtles benefit from selective, light pruning to maintain their health and form. The goal of proper pruning is to thin the canopy to improve air circulation and sunlight penetration, which helps reduce the risk of fungal diseases. This process focuses on removing specific types of unwanted growth rather than reducing the overall height of the tree.
Proper maintenance pruning involves removing:
- Suckers, which are unwanted shoots that emerge from the base of the trunk or the roots.
- Branches growing inward toward the center of the canopy.
- Branches that are crossing and rubbing against each other.
- Dead, diseased, or broken wood.
Cuts should always be made cleanly just outside the branch collar—the swollen area where the branch meets the trunk—or back to an outward-facing bud or side branch to encourage growth away from the center.
Optimal Timing and Pruning Schedule
The best time to perform any necessary pruning is during the plant’s dormant season, specifically in late winter or very early spring, just before the emergence of new growth. This timing allows the plant to heal before the active growing season begins and makes it easier to see the tree’s structure without the leaves obscuring the branches. In many regions, this optimal window falls between late January and early March.
Pruning too early, such as in the fall or early winter, can stimulate new growth that does not have time to harden off before freezing temperatures arrive. This tender growth can be easily damaged by frost, potentially leading to dieback. For a healthy, established crepe myrtle, pruning is typically only required every few years to remove dead wood or correct minor shaping issues. Since crepe myrtles bloom on new wood, minor selective pruning in late winter still allows for abundant summer flowering.