Yes.

yes, you can cut them back near the ground if you want but they will still bloom with the leaf miner, unlikely to re-bloom if you cut them back but if the fall is mild you will get some reblooming. Mine were cut back to the ground by sawfly larvae and last fall was so mild that we had blooms still coming out in early November. not typical though.

Barb
southern Ontario, CANADA

I would just add, if the seeds are ripe (they should be by now) spread them for reseeders before you cut back and discard.