How hardy is Azolla?

I keep seeing different zones listed for this floater. I'm going to assume at least zone 8. Does any one overwinter this in zone 7?

Thanks,
Sheila

It winters quite well in a dish of water, in a window, in any zone

;)

A series of hard freezes will kill the bulk of it off, in North Carolina zone 7b, pockets of it manage to Winter over in spite of 10°f freezes through Winter, being small and miniscule, it manages to find a few frost free nooks and crannies

Regards, andy