I cut mine back each year after the last freeze or frost because it is much too large for the spot it is in. It resprouts and blooms heavily each fall.

I'd cut them back now and again after spring bloom. Otherwise, they get "leggy" and try to lay over.

whitecap, your fall aster blooms in the Spring??? Mine bloom only LATE summer and into fall.

Now that I study on it, perhaps I had a "senior moment." I took mine out about 8 years ago. I just couldn't keep them upright, and I had a cat that liked to get into the bed and roll around in it. It wasn't until long after that I discovered that they are supposed to be cut back before fall. I believe the "authorities" say they should be cut back by half in late June or early July.

I have a few of those myself........all I knew was that if you had one, I wanted one.............LOL> I think they are beautiful....just don't bloom enough.