This week I saw my first severe pruning of a crape myrtle for this dormant season. It never ceases to amaze me to see the various pruning methods that we perform on this tree.   How to prune crape myrtle is always a popular subject whenever I make a presentation about pruning trees. The discussion always seems to center around how far back you should prune them. Unfortunately, for many folks pruning crape myrtle is often synonymous with topping the tree.

When did this practice start

Most arborists are not sure where the practice of topping crape myrtles started.  The practice has been around a long time.  The technique of severely pruning crape myrtles has even been given a name.  The term “Crape Murder” has often been attributed to originating from master gardeners upset with the practice but according to Southern Living Magazine, the term was first used in a 1997 article written about the hard pruning practice. I like to use the term “crape hate” as the topping cuts don’t usually “murder” the tree but disfigure it instead.

Is topping crape myrtle harmful?

Where did the practice of severely pruning (topping) trees start? Perhaps it was done after someone observed trees in Europe being pruned with the pollarding method.  Perhaps it was someone that needed to reduce the height of the tree because it got too tall. What benefits could there be for the tree.  While the benefits of crape myrtle topping cannot be found, the harm it does to trees well known.

• The heavy pruning disfigures the profile to where the tree no longer looks like a tree.
• It creates large scars that are visible for several years.
• The blooms after topping are produced on thin vigorous growth that cannot support the weight of the bloom causing it to droop down.
• It creates more maintenance on an otherwise low maintenance tree.

In the past, it was true that you pruned crape myrtles to reduce powdery mildew infestations. With the breeding of plenty of cultivars that are resistant to the disease, crape myrtles require very little pruning. In fact, a crape myrtle planted in full sun with plenty of space to grow needs little to no pruning at all.

Incorrect assumptions for improper pruning

The reason most often used for topping crape myrtles is that they have gotten too tall.  The solution is simple. There are over 1200 varieties of crape myrtle with mature heights ranging from 2 feet to 40 feet.  All you need to do is purchase the variety of crape myrtle that meets your height requirement.  To look at the various varieties and sizes go to: https://extension.msstate.edu/publications/crapemyrtle-flower-the-south, or https://hgic.clemson.edu/factsheet/crape-myrtle-varieties/

Another incorrect  reason given for topping crape myrtle has been that the topped trees bloom more. Recent research from Drs. Gilman and Knox at the University of Florida has demonstrated that the number of crape myrtle blooms decrease in direct correlation to the size of the branch removed.  In other words, the larger the branch removed, the fewer the blooms.  However, blooms on pruned trees were larger than blooms on un-pruned trees. To receive the benefit of larger flowers from pruning, prune just pencil sized branches without jeopardizing overall tree health caused by topping the tree

Proper pruning

If you find yourself in the position to prune crape myrtles, here are a few simple steps to follow.

• First, prune sucker sprouts and basal sprouts. If left to grow, these sprouts may form woody stems that eventually compete with existing main stems.

• Second, prune any rubbing or crossing branches, as well as dead branches. This may include branches that are crossing through the canopy from one side to another. As always, make the pruning cuts at the branch collar.

•  Third, (this one is optional) tip prune the branches to remove spent flower buds. This is also called pencil pruning because the branches removed are no thicker than a pencil.

While properly pruning crape myrtles is the most labor intensive,  it also results in a more aesthetically attractive tree. The best way to avoid over-pruning crape myrtles is to choose the correct cultivar that matches the location where you wish to put it. For more information on pruning refer to: https://edis.ifas.ufl.edu/pdf/EP/EP39900.pdf

As we think about pruning crape myrtles perhaps this year we will hold off on the heavy pruning and prune crape myrtles properly.

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