I think I got lucky a few years ago planting mums in the garden as soon as they were on store shelves, when fall was really just a whisper- they must have had enough time to establish roots before winter. Come spring they all came back, and bloomed by late summer through fall. I tried a few more in protected places, and still had success. Coming to Minnesota, however, I surely did not think they would over winter. I brought them mostly to assure I had them one more fall. Little did I know we'd have the most mild winter, and come spring I would have the largest mums I've ever had. I've read about the Minnesota mums, bred to be super hardy here, but to my knowledge these babies aren't supposed to be reliably hardy. So you never know, this may have been their last time to shine... we won't know until spring.
I know this Rusty one below is 'Hannah'
A few snapdragons crept in the shot, too.