Q.When And How Should You Trim A Crepe Myrtle Tree?
The branches on the side are growing over my fence and the neighbor is complaining but I was told to cut in fall or winter. It is in the 90’s in Chattanooga, Tennessee and I’m worried that pruning may kill it. I have three in a row beside this fence.

I would be surprised if that kills a Crape Myrtle. Here in Texas, they grow like weeds and it is near impossible to kill them. I actually tried to kill one that had multiple trunks and, years afterwards, it is back with several trunks over 15-20' tall (obviously, I gave up trying to kill it and let it grow back). I never prune mine unless there is a good reason. Then I prune when dormant: in the fall, winter or early spring. I suspect to keep the peace, you may have to prune now but, if it is ok with the neighbor to wait then wait. I have pruned in July-September after thunderstorms broke some branches though.