mums!
Yes! I love them--just discovered this thread--
I used to hate on them...like they were some kind of banal, inferior plant...but my opinion has changed over the years and I really appreciate the heck out of them every fall because they bloom later and longer (at least the daisy types) for me than the asters.
I'll put some pictures in later--
Regarding overwintering and when to plant: I second what Jennifer says about good drainage! In my experience, good drainage is the key and fall planting has never been a problem for me. In fact, all my mums were originally planted in the fall, and dug up and relocated (after blooming) also in the fall, and I'm a good bit colder here than y'all.
It's not so much the cold--they just don't do well being wet and cold/frozen.
I find that they have a pretty shallow root system once established in the garden--as compared to in a pot--and I think that plunging potted mums into poorly draining soil, watering them in well, and then mulching heavy for the winter is what kills them. Granted, there are many different types of mums, and most of the mass produced decorative mums for fall sales are not 'hardy' types--but I have even successfully and unintentionally overwintered them in containers left for dead and dry on the porch, so go figure...