This is the time of year for pruning Crape Myrtles, and therefore it is when Crape Myrtles suffer at the hands of well-intentions gardeners and landscape companies. When I drive around Atlanta this time of year I witness Crape “Murder” on a grand scale, and most people think this hatchet job (or chainsaw job) is the proper way to prune Crape Myrtles. When did the collective gardening community decide that pruning Crape Myrtles was an act of aggression? When did it become a gardening task for which a chainsaw was needed?
Structural pruning of any kind, including pruning Crape Myrtles, has become more important, but also more risky in the Atlanta landscape. The weather in Atlanta seems to change from zone 9 to zone 3 on a moment’s notice. This past summer lasted a full 6 months and recently, winters bring frequent snows and temperatures in the teens. Atlanta used to enjoy a full four seasons but today we seem stuck with only a harsh winter and an oppressive summer. Well maintained, properly pruned plants are better equipped to survive the extremes of drought, flood, heat and cold.
Properly pruning Crape Myrtles helps resist fungus, disease and insects. It can also help to improve the production of flowers. Pruning Crape Myrtles properly will also help to highlight one of the main winter features of a Crape Myrtle, their unique and beautiful trunks. On the other hand, while improper pruning is unlikely to kill them, it can make the trunks unsightly and increase the probability of damage from disease and insects.
If it isn’t obvious from the first paragraph, we don’t advocate the “technique” of taking a chainsaw to a Crape Myrtle and giving the tree a flat-top at six feet tall. When was the last time you gave your Oak tree or Maple tree a flat top? Hopefully, never. A Crape Myrtle is a tree just like an Oak or Maple.
So, how should you go about pruning Crape Myrtles? First of all, start with a sharp tool to do the job right. Ragged cuts from dull pruners look bad and can cause problems. And please, take three steps back from the chainsaw. For starters, either snap off or prune off all the little branches that have sprouted in the past year. If these were left to grow and fill out they would clutter the interior of the tree, rub against other branches and create such density the tree is guaranteed to have Powdery Mildew by spring. Removing the small, newer growth means the canes that can generate flowers will have the space, the energy and the nutrients to do so.
The next step in properly pruning Crape Myrtles is to remove branches that are crossing or rubbing together. Even larger canes, the size of your thumb or larger, can come completely out if the tree is too dense. Crape Myrtles grow fast during the summer months and their flower heads can get quite large. Thinning them out will have multiple positive effects. First, branches that are so close that they can rub together will ultimately cause wounds on the bark of the tree, which can cause a whole host of problems. Second, if the canopy of the tree is too dense the flowers will never fully develop because they need more space. An overly dense canopy is also a recipe for powdery mildew, mold and other potential problems. For some reason, amateur pruners are hesitant to thin plant density, but remember, pruning is your friend. Proper pruning will result in richer flower production and fewer problems with disease and insects.
Now when it comes to pruning the height of the Crape Myrtle tree you have a wide range of options. It is not necessary to attack the height with a vengeance, taking a 20 foot tree down to 8 feet. As a matter of fact, you really don’t need to do anything in this regard.
One excellent approach is to simply deadhead the tree, taking off the dead blooms and a couple of inches of the cane – nothing more. This, actually, is the ideal approach to pruning Crape Myrtles and it is the way we would prefer to prune Crape Myrtles. As a general rule, we avoid pruning canes larger in diameter than your index finger. We make exceptions, of course, especially if the tree has outgrown its environment and needs to be pruned back down to size.
The bottom line is that Crape Myrtles don’t need to be pruned at all, but they are very resilient trees and recover from all the mistakes that amateur pruners make. But if you want the best results from your Crape Myrtle, and you want to avoid the large knuckles, mold and mildew, use our technique of light, structural pruning and test the results for yourself.
Happy gardening. And remember, in the garden be bold when it’s cold!
My Personal Gardener is a full-service landscape company in the Buckhead area of Atlanta. We are avid hand-pruners and shun the use of power shears. If you are interested in learning more about the work we do please visit us at www.residentialmanagementgroup.com .