This seems to be a question that many people get confused with often. Crape Myrtles are tricky in that they look good and hold their shape very well during the late fall, winter and even in the spring, but then in the early summer, will put off an extreme amount of new growth right before they bloom. By the time they get overgrown, they are in bloom and you don’t want to prune them, but they are hanging over sidewalks and in places you don’t want them. Sound familiar?
The best way to fix the Crape Myrtle pruning problem is to always make sure to prune them in the winter. Now I know you don’t want to get out in the cold weather to prune a crape myrtle, but I have also heard you complain about getting out in the heat to prune all your other shrubs! So, get over it! You can do it, I know you can. In Nashville, you can prune them all the way through April with no chance of destruction.
Be very selective as to how you prune your crape. If you are careful in your pruning, no one will even notice that you have pruned it. A small saw or a pair of loppers works really well for pruning.
Crape Myrtles are about the last deciduous plant in the spring to put off new leaves. It is fun to get those phone calls of people that think their crape is dead the first year that they own it. As the tree leafs out and starts putting off new growth, you can use hand pruners and keep it touched up. This time of year is very critical to keeping the size and shape in check for it to look perfect while it is blooming in late summer. Prune off the branches that are heading in the wrong direction. The wrong direction would be the ones cris-crossing each other, or the ones that are heading into the middle of the plant.
Don’t be scared of the pruning. After once or twice of doing it, you will know exactly what you are doing and will be very glad you took the time to learn.