Our cool, wet April and May really gave them a slow start. Check the plants all around town, many are just now peaking. The powdery mildew fungus is very common on crape myrtles, and unless you have a heavy covering, it usually is more a nuisance than anything else. The reason it is more prevalent on the bottom of the plant, is the sunlight is reduced as well as air circulation. When we were in Little Rock a few weeks ago, we admired the crape myrtles that grow like a tree, rather than a spreading bush.
Crape myrtles vary in shape and height based on the variety as well as how they are pruned.
There are dwarfs up to standards. If you have a standard, choose one to five main stems, prune everything else out. Then each season, gradually shape these branches, allowing for a full upper canopy. Prune off suckers and sprouts as they appear. Pruning is best done in late February.