Sorry, I thought I had my usda zone listed in my profile:)
I am supposedly in zone 5b, but because I am in a rural setting with no wind protection, I usually try to buy zone 4 plants. From experience, many zone 5 plants do not survive my winters.
Mums of Minnesota offers many mums that are rated to zone 4. Many were developed by the Univ of Minnesota.
https://www.fgimn.com/index.ph...
