The 4th of July is THE DAY to have your floppy plants pinched back by so that they still bloom before it snows. I pinch my tall Sedums (like Autumn Joy, Emperor) and Asters (natch!) and my Chocolate Eupatorium. But I've had great luck at pinching Joe Pye, too.
Want me to tell you how to pinch? I'm not that kind of blog. Just get out there and experiment.
I like to pinch when I'm on the phone.
I don't know why you needed that information, but there it is.