The Crepe Myrtle (Lagerstroemia indica) is an ornamental plant celebrated for its extended summer bloom period and attractive exfoliating bark. Proper pruning is necessary to encourage vigorous flowering and maintain a graceful, healthy structure. The timing of pruning is crucial, as careful attention to the plant’s seasonal cycle ensures both its health and aesthetic appeal.
The Best Time for Major Pruning
Major structural pruning should be performed only when the Crepe Myrtle is completely dormant, typically during late winter or very early spring. This window generally falls between mid-February and March, after the coldest temperatures have passed but before the new buds begin to swell. Pruning during the dormant season reduces stress on the plant.
The Crepe Myrtle is a “new wood” bloomer, meaning its flowers develop exclusively on the growth produced during the current season. Pruning in late winter allows the tree the entire spring and early summer to generate the strong new growth needed for an abundant flower display. Pruning too early can stimulate premature new growth highly susceptible to damage from a late-season frost.
Essential Pruning Techniques to Maintain Shape
The most damaging pruning error is “Crepe Murder,” which involves severely topping the main branches, leaving thick, unsightly stubs. This technique ruins the tree’s natural form and forces the plant to produce weak, vertical shoots too flimsy to support heavy summer blooms.
Proper pruning focuses on selective thinning and shaping to open the canopy, not on drastically reducing height. The objective is to allow light and air to penetrate the center of the tree, promoting strong growth and helping prevent issues like powdery mildew. Begin by removing any dead, diseased, or crossing branches that rub against one another, which can create wounds that invite pests or infection.
Structural cuts should always be made back to a larger branch, the main trunk, or to an outward-facing bud. This encourages new growth to extend away from the center, maintaining an open, vase-like shape. For multi-trunk specimens, select and maintain three to five well-spaced, strong main trunks, removing any others at ground level.
Suckers, which emerge from the roots or base of the trunk, should be removed as close to the ground as possible to prevent them from diverting energy. Similarly, remove water sprouts, which are fast-growing, vertical shoots appearing on the main branches, as they do not contribute to a healthy canopy structure.
Ongoing Maintenance During the Growing Season
While major pruning is reserved for the dormant season, minor maintenance tasks can be performed during the summer to enhance flowering. Deadheading, the removal of spent flower clusters, is recommended to encourage the plant to produce a second or third flush of blooms.
Deadheading involves snipping off the entire faded flower head or the small seed capsule that forms after the petals drop. Removing spent blooms redirects the plant’s energy away from seed production and into creating new flowering wood. This maintenance should not be performed too late in the season, typically after early August, as stimulating new growth too close to winter can delay dormancy.
The removal of suckers and water sprouts can be performed year-round as they appear. Removing these unwanted growths when they are small minimizes the wound size and reduces the possibility of disease. These light cuts do not subject the plant to the stress of heavy structural pruning, allowing the Crepe Myrtle to direct its energy toward a prolonged display of summer color.