I would not plant iris now. From my personal experience, I divided some iris early one November, most survived & even got a little bloom the next year. These were EXTREMELY hardy heirloom iris that I had lots & didn't matter if I lost them. It was also a warmer than usual year. I am considered to be zone 6, but overwinter lots of plants that are zone 7 & 8, so I really think I am warmer than you. I never mulch my iris, but if you do mulch, I would wait til after the ground freezes.

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If you can get them in the ground at least 6 weeks before your 1st hard freeze then they will be ok....but I would think a month would be OK. The biggest concern is winter heave.. If you plant them now I would watch them for heave and press them down if that happens.. Do get snow cover??

We get snow, but then it thaws and then it snows again. It just goes on like that all winter. I will keep an eye on them. Is it better to mulch or not to mulch? I also planted some potted iris plants a few weeks ago. I am not worried about those, but I just noticed that one of them had some rot forming on the end of one of the rhizomes. I just cut it off a little past the soft part so I hope the rest of the plant will be ok. It had been in a pot for a really long time and I think the plant got stressed and root bound. I am wondering if I should dig it up and try to spread out the roots or just not worry about it.