Crepe myrtles (Lagerstroemia indica) are popular ornamental trees and shrubs, celebrated for their vibrant, extended summer blooms. These deciduous plants shed their leaves in the fall, providing a beautiful display of smooth, mottled bark through the winter months. Proper trimming during the dormant season is necessary to ensure the tree’s health and encourage a spectacular flowering show each summer. Understanding the correct methods for this winter care maintains the tree’s attractive natural form and prevents long-term damage.
When to Prune and Necessary Tools
The ideal time to prune a crepe myrtle is during its dormancy, specifically in late winter or very early spring (January through March). Pruning at this time prevents frost damage to new growth, which can be stimulated if cuts are made too early. Since the crepe myrtle blooms on new wood, trimming just before the growing season maximizes the production of flowering shoots.
Pruning should be avoided in late fall or early winter because a sudden warm spell could trigger new, tender growth. This tender growth is highly susceptible to freezing temperatures and can draw moisture and cold into the plant tissue. Waiting until the coldest part of winter has passed minimizes the risk of winter injury and allows the tree to focus its energy on recovery and blooming.
To make clean, precise cuts that heal quickly, you will need specific tools. Clean, sharp bypass hand pruners are appropriate for small branches up to a half-inch in diameter. For limbs between a half-inch and one and a half inches thick, long-handled loppers provide the necessary leverage. Any branches exceeding one and a half inches should be removed using a pruning saw. It is important to clean and sharpen all tools before use with rubbing alcohol or a weak bleach mixture to prevent the transfer of pathogens.
Step-by-Step Proper Trimming Technique
The initial step in proper trimming is to remove all suckers, which are vigorous shoots growing from the base of the trunk or roots. These shoots steal energy from the main plant structure and should be cut off cleanly as close to the origin point as possible. Next, focus on removing any dead, diseased, or broken wood, as this material can harbor pests and disease.
Once the deadwood is cleared, the goal shifts to thinning the canopy to promote good air circulation and light penetration, which helps prevent fungal issues like powdery mildew. This involves selectively removing small, twiggy branches growing inward toward the center of the tree. Also, remove any crossing or rubbing branches, as the friction can wound the bark, creating entry points for insects and disease.
When reducing the size of the canopy, always make cuts back to a larger limb, the main trunk, or an outward-facing bud. This technique directs new growth away from the center of the plant, helping to maintain the naturally graceful, vase-like shape. For larger branches that must be removed entirely, use the three-cut method to prevent the bark from tearing down the trunk. This method involves an undercut, a top cut to remove the weight, and a final, clean cut just outside the branch collar (the slightly swollen area where the branch meets the trunk).
Understanding and Avoiding Crepe Murder
The term “Crepe Murder” refers to severely topping the tree, which involves cutting back all main branches to thick, unsightly stubs or “knuckles.” This method is often mistakenly used to control the height of an oversized tree or in the belief that it promotes better blooming. However, topping a crepe myrtle causes significant stress and ruins the plant’s natural form.
When a tree is topped, the severe cut stimulates the rapid growth of numerous weak, whip-like shoots, often called “witches’ brooms,” directly below the wound. These shoots are weakly attached and unable to support the weight of the large flower clusters and foliage, making them prone to breakage during storms. Repeatedly topping the plant creates a knobby, disfigured look that is unattractive when the tree is bare in winter.
This practice compromises the tree’s structural integrity and overall health. The large, open wounds left by topping cuts expose the wood to decay, disease, and insect infestation. Instead of topping, selective thinning and reducing the canopy size by cutting back to a strong lateral branch or bud is the correct approach to maintain the tree’s health, strength, and elegant structure over time.