Ask Allen ~ "Pruning 20-foot-tall Crape Myrtle"
Question: Cheryl Wood: Please advise on how to get a Crape Myrtle back to a manageable height after reaching 20' tall.
Allen's Answer: Cheryl, Thanks for your question. First, let's talk about what not to do. Many people plant Crape Myrtles in locations that, over time, become too large for that location. Then they top the tree, leaving unsightly stubs that, over time, create knots that produce numerous, weak new shoot growth. This causes stress to the tree, making it more vulnerable to pests and disease, along with the undesirable aesthetics it creates. Now, let us look at pruning your tree.
Here are a few things to consider when pruning:
- Never remove more than 1/3 of the branches.
- Use the 3-D’s when removing branches: Dead, Diseased and Damaged.
- If the tree must be downsized, do a crown reduction, using reduction cuts rather than topping as I described earlier. By doing a crown reduction with reduction cuts, this will keep your tree more symmetrical and will maintain a normal appearance. Reduction cuts are made by moving down from the tallest limbs to a lateral limb (at least 1/3 the size of the limb you are cutting) and making your cut just above that limb. This will minimize new excessive growth, which causes weak limbs.
- Heading cuts are the least desirable, and should only be used as a last resort when lateral limbs are not available. These are made by cutting the limb just above a node (i.e. - growing point). This will cause excessive growth, which is the reason it is not recommended.
Good Luck. Crape Myrtles actually require very little pruning when the right size tree is planted in the right place. There are numerous sizes of Crape Myrtles, all the way from a shrub that only gets a few feet tall up to the large varieties.
To "Ask Allen" a question, email AskAllen@cityhs.net.
Allen Bates is the City of Hot Springs urban forester, and he manages the City’s urban forestry care, preservation and health plan to provide the City with a safe, healthy environment for the City's urban forest.