Probably depends on where you are. Most of my leaves in Monroe county are just starting to change colors. I imagine that the moisture(what little there is with no rain for months) is headed back to the roots at a good rate. If your leaves are already falling I’d suppose it might be a little late but I’m new to this control method myself. I did a stand of sweetgum at the end of September and they are turning noticeably brown on the tops.
