A misconception that Crape Myrtles need to be severely cut back in late winter or early Spring has led to an unhealthy practice of topping these plants.
Topping Crape Myrtles can lead to stem decay and eventual plant death. Proper pruning requires the same procedures used for any tree or shrub. Maintain the shape & form of the plant by removing dead, diseased, broken, crossing & rubbing branches.
Pruning needs to be done in late Winter or early Spring.