There are several different types of Crape Myrtles. There are the Tree like, the Shrub like and the Dwarf. Then there are those in each class that have unique characteristics such as leaf texture, bark color and of course color of flower. Therefore, different levels of care are required for each.
Tree like crape myrtles should be planted to allow for a large growth habitat; somewhat the size of a small tree, trimming of should also mimic that of pruning a tree.
Shrub like can be allowed to grow large but this cultivar is generally pruned to maintain height and maximize flower production. This is done successfully by pruning in the late winter and in some cases trimming it during the growing season.
The Dwarf is of course the easiest of all to care for, with little trimming requirements.
Regardless of type, all require feeding with a slow release fertilizer. In the event that they become ill, a Certified Arborist who specializes in Tree Health Care can diagnose and recommend the appropriate prescription.