Answer: It is likely suffering from stress due to its lack of an extensive root system to support the top growth during these hot summer months. Despite the rain and moist soil, the plant is likely suffering from a lack of moisture, as its roots have not had enough time to grow and establish a large, extensive network in a large volume of soil. Give it a good soaking once every 3-5 days in the area within about 5 feet of the trunk.
Prune it properly in late winter. For more information on proper crape myrtle pruning, check out the following web site:
By next spring and summer it should be better established and ready to take on the hot weather.
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