How to Prune and Trim a Crepe Myrtle Tree
I have two mature Crepe Myrtle Trees in my backyard and they get plenty of sun and have always put out an abundance of blooms. This year only one has a lot of green leaf growth the other has little greenery and the rest of the branches are dry and. How should I prune it? It does have a lot of new leaf branches at the base of the tree. The healthy one is about 10 yrs. old and the younger one maybe five. We usually don't get a professional landscaper so we weren't sure how far back to prune or just prune from the bottom and conservatively from the top. Any suggestions would be appreciated. Thank you for your help.
Crapemyrtles can be marginally hardy in our area, and have dieback of branches (or even roots) when our winters are harsh. It sounds like that may be what happened to your second plant. The good news is it is returning from the base.
Planted in a space that suits their mature size, crapemyrtles require very little pruning, other than to remove problem branches or dead wood.
You can probably leave your healthy looking one alone.
Dead wood can be trimmed away from the other one.
Starting at the top of the longest branches, gently bend them. If they snap, they are dead and can be removed. Keep moving down the branch toward the center of the shrub. If the branch is pliable, scrap it with a fingernail and see if it is green beneath. That may still be alive.
Here is a Virginia Extension publication that will help you with pruning Crapemyrtle: