Q: Help! The bark is coming of my crepe myrtles, what is causing it and what do I spray it with?
A: No need to panic, if it is what I think you are talking about it is a natural process that happens every year, more some years than others. The old bark is sloughed off as the new grows under it. Now if what you are talking about is a definite physical injury that has happened by a weed trimmer or lawn mower, you need to care fully clean the area of dirt or debris and leave it alone, it should heal on its own. Crepe Myrtles are tough plants, but keep a cleared area around the base and weed by hand, the bark on crepe myrtles is very thin.