How to Grow a Crepe Myrtle Tree

Crepe myrtles love full sunshine with a minimum of 6 hours a day. They will grow in partial sun or shade but will likely not flower as much. Planting these trees in a shady location is the most frequent cause of failures to bloom. 

They are not picky about their soil as long as it drains well; they do not like a wet, soggy site. In contrast, crepe myrtles are drought-tolerant once established, which is one of the reasons they are low maintenance. Crepe myrtles prefer neutral to slightly acidic soil. If soil gets to alkaline (above 6.5), this may cause yellow leaves; add garden sulfur to lower the pH; coffee grounds can help,too.

Think about proximity to sidewalks, powerlines, and other obstructions. Picking a tree-sized crepe myrtle to plant under your first-floor window might result in a lot of annual pruning in the following years. A crepe myrtle that grows to 25 feet tall and wide might get you in trouble with your electric company if you plant it under the power lines. 

Do future you a favor and plant the right shrub in the right location.

When to Plant Crepe Myrtles

In USDA zones 7 to 10, crepe myrtles are best planted in the fall or early spring. However, if you grabbed a crepe myrtle from the nursery or garden center in the summer because it caught your eye in full bloom, don’t worry. They can be planted in summer as well. 

Regardless of planting time, keep an eye on it and water it regularly as it becomes established. It will be especially important to give a newly-planted crepe myrtle lots of water in the summer months to promote good root growth. Don’t stick it in that sunny spot in the backyard in August and then go on vacation for three weeks. 

How to Plant Myrtles

Plant crepe myrtles as you would other shrubs or ornamental trees. Check this page from Penn State Extension for more information on how to plant ornamental shrubs and trees.

• Start by giving the tree or shrub a thorough watering while it is still in the original container. Not only will it slip out of its pot more easily, but you’ll also minimize stress on the tree.
• Remove the sod (if any) and place it aside to compost later.
• Dig a hole as deep as the root ball but about three times as wide. Ideally, the hole should look like a shallow bowl, not a well.
• Clip any circling roots, sometimes called girdling roots. If your new crepe myrtle is rootbound, score the outer edges of the rootball to stimulate new growth. Rough it up a little. 
• Place the plant in the hole. It should be sitting so the old soil level (from when it was potted) will be at the same height when the hole is filled in. 
• Backfill the hole with the soil you removed, and tamp it in firmly. You don’t want air pockets down by the roots. Pause when the hole is partially refilled and water, then continue backfilling.
• Make a ring or wall of soil an inch or two high in a circle around the shrub or tree to help water infiltrate instead of running off, then water again. 
• Apply mulch 1 to 2 inches deep. Use an acid mulch such as pine bark or oak leaves for crepe myrtles.

Mulch tip: Don’t pile the mulch up around the trunk like a cone. Mulch should not contact the stem of the tree or shrub. Make a donut, not a pyramid.