That won't hurt it at all. Go for itThumbs Up

I trim back crepe myrtles clear on into mid summer sometimes down here in Florida, only thing I've ever seen hurt them is moss if it gets out of control or heavy shade will kind of stunt them.

 

Mine usually seems dormant until the beginning of June, but my climate is colder than yours.

 

You are good. Hard to hurt these. I had some delayed growth on a few qe did last year but they soon caught up. Had been pencil pruned and customer wanted it taken down about a foot lower than that. So pulled out the chainsaw and crepe murdered it. All good.

 

I'm in Ohio. I like doing any hard cutting in March. To avoid winter damage. Also helps kick off the season.

https://www.trees.com/gardening-and-landscaping/crepe-myrtle-pruning#When-to-Prune-Crepe-Myrtle

 

Pretty difficult to hurt one outright, you can hack away at it anytime. I usually do it once the sap goes down but trimming it back in summer when its growing like bonkers is just fine, it'll pop right back out.

 

I happen to disagree with trimming a crepe myrtle back to 6ft to 8ft by completely removing the top of the tree is the WRONG WAY TO TRIM A CREPE MYRTLE.
A crepe myrtle tree is vased shaped to 25 to 40 feet tall. When it flowers it will weep outwards forming a vase.
I have seen what happens when it is cut back year after year to sticks standing out of the ground.
It will weaken the tree in the long run.
The blooms won't be as prolific as they should be. It makes the tree susceptible to diseases and will eventually die.
I would trim crepe myrtles by thinning out some of the branches that cross each other while maintaining tree height.
I wish home owners and landscape contractors would stop trimming crepe myrtles this way it destroys the beauty of the crepe myrtles. I had a customer do this for about years and his crepe myrtle died.

 

It's a cultural practice. I don't like it. Many homeowners and commercial properties (for size reasons) do this every year. At this point in the season if they are budded out with new growth I say no to them unless HO just absolutely wants it done. I've got 2 eighty year old crepes in my front lawn. I only prune out dead and overlapping branches.

 

Hey guys I started my lawn care business about a year and a half ago. I have a customer that wants me to cut 5 crepe Myrtle’s that are about ten foot high down to about 5 foot high. I’m just getting into this side of the business and was wanting to know how much should I charge and should I do this at all

 

 

Get Micheal Dirrs book on shrubs, also look at tree trimming quides with Crepe Myrtles...they can be trimmed almost any way, but so they prosper and look like they should, whacking them is not the way.....what state are you located?

 

Southern Louisiana

 

You can cut them pretty good, they will look funky....tell the customer.....hard to kill but they will die....eventually

 

I told her that and she told me she already knows she’s work in horticultural and botany when she was younger so she told me she already knows she said if they go they go