I live in St.Louis. Seems like I should be seeing buds but keep getting green foliage and no buds. Is it too early? Gardener told me I could prune about waist high, which I did. These bushes have always been huge loaded with blossoms.
Excessive pruning or topping of Crepe Myrtle is often referred to as 'Crepe Murder'.
Light pruning is recommended instead and you can prune to a more formal style or a natural appearance.
Pruning should always be done when the shrub is dormant, so winter or early spring.
A Crepe Myrtle blooms on new growth, so you may have blossoms this year, but it may need plenty of time to recover.
Here are some links that have more information.