How to Prune a Crape Myrtle

If you’re looking for a hardy, low maintenance plant that comes in a multitude of shapes and sizes to suit any garden, look no further than the popular crape myrtle. Many homeowners find themselves truly enamored by this plant, and it’s not hard to understand why: it comes in an awe-inspiring variety of shapes, sizes, and colors, and can bring a perfect pop of summer color to your outdoor area.

The crape myrtle is also one of the perfect plants for the Pacific Northwest since it thrives in hot and humid conditions and is also known for its drought tolerance. It doesn’t require a great deal of sunlight. As long as it’s receiving about six hours per day, the plant will do just fine.

Unfortunately for this wonderful plant, it is often pruned incorrectly by its well-meaning owners. If a plant isn’t pruned correctly, the branches can be damaged and the flowers can come in late or even fail to grow entirely. Far too many would-be gardeners end up butchering their crape myrtle plants in a misguided quest to keep them healthy.

And while the crape myrtle is known for being a hardy flowering plant that can thrive in difficult conditions, it does require a certain amount of upkeep and failing to prune it isn’t an option.

If you really want a healthy plant that’s going to produce the vibrantly colored summer flowers that the crape myrtle is known for, then you’ll need to provide it with at least some care.

With that said, there’s a right way and a wrong way to care for your landscape: this guide will give you a few helpful tips on how to prune crape myrtle plants.

First, Make Sure Your Plant is Healthy

There’s no point in trimming your plant if it hasn’t been properly cared for throughout the year. While hardy, the plant is vulnerable to insect infestations and common tree diseases. Powdery mildew, sooty molds, lichens, and aphids are all threats that can damage your crape myrtle.

We recommend regularly inspecting your plants for any signs of disease; check underneath the leaves for dark spots which could indicate a fungal infestation, and look at the bark for any sign of an insect invasion.

If you notice any signs of damage or disease, you’ll want to seek help from an expert arborist such as the ones at Mr. Tree. In these instances, your crape myrtle will likely need to be pruned by a professional.

Fertilize to Ensure Flower Growth, Not Excessive Leaf Growth

It’s also important to ensure that your plant is well-fertilized. You don’t need to do this very often, however; once or twice a year is plenty to ensure your crape myrtles get enough nitrogen.

The most effective way to fertilize a crape myrtle plant is to wait until the early spring, after any frost and as soon as the first leaves start to appear. Once those leaves begin to show up, apply a slow-release fertilizer with a high nitrogen content. A relatively small amount of fertilizer will be fine; you don’t need much. In fact, if you overdo it, you’ll probably experience sucker growth on your tree.

Suckers are small and weak branches that need to be pruned or will otherwise leave your plant vulnerable to insects. Not only that, your plant will start growing leaves out of control and may fail entirely to produce flowers. Keeping the amount of nitrogen in the fertilizer small will prevent excessive branch and leaf growth.

Make Sure Your Pruners are Sharp

This next step is critical not just to the health of your tree, but to your safety as well. A set of pruners with a dull or blunt set of blades will not cleanly cut through the branches of your tree. Instead, you’ll have jagged cuts that leave your crape myrtle stressed and vulnerable to insect infestation and disease.

Sharpen your pruners before using them with diamond files. If you’re only using the pruners to care for your crape myrtles, you’ll only be using them a few times a year at most. That means you’ll only need to sharpen them once per year. However, if your pruners are seeing regular use, you’ll want to sharpen them at least once every six weeks.

Clean your pruners with warm, soapy water and scrub off any rust with coarse steel wool. Carefully sharpen your pruners using the diamond files and finish the process with a few drops of silicone-based lubricant.

Start Pruning at the Bottom

When it comes to crape myrtles, the framework is crucial to the appearance and overall health of the tree. As they grow, crape myrtles tend to want to produce multiple trunks; too many of these, and they’ll compete for resources with the rest of the plant. You’ll want to trim the number of trunks down to just a few.

This will also prevent you from having to do extra pruning work down the road; instead of many weak branches, you’ll be left with a smaller amount of strong ones. When you prune, cut all the way to the soil and attempt to leave the stronger trunks while removing the smaller ones. If you notice any suckers – small, weak branches – prune those as well.

Work Your Way Up to the Crown

The most important part of pruning a crape myrtle is maintaining a healthy tree and removing excessive trunks and suckers you see. Nevertheless, you’ll also want to begin moving upward, toward the top of the tree, gradually thinning out the crown.

If the branches of your crape myrtle have become tangled, you’ll need to trim a few of the excessive ones away to allow the healthy branches to grow and spread unimpeded. Thinning the crown will also allow air to circulate through your crape myrtle branches more effectively and allow sunlight to penetrate the entire plant.

Don’t Be Afraid to Ask For Help

While we hope this guide has given you a few critical tips on how to prune crape myrtle plants, it’s sometimes better to contact a professional. All too often, improperly pruned crape myrtles can become sick and fail to produce flowers.

If you are unsure or if the work seems daunting, don’t be afraid to ask for help. Contact an expert arborist for pruning services, as well as tips and advice for caring for your trees.