Hardy in zone 10 does not usually mean "invasive" in zone 5. Can't help much on the plant specifically.

FataMorgana

More worried about it dropping thousands of seeds and escaping to other areas, than the plant itself surviving a winter here.

Garlic Mustard & Teasle spread primarly by seeds and they are causing all sorts of trouble around here. I would hate to accidently introduce another problem plant.

My experience with tender items like those hardy in Zone 10 is that their seed tends not be very winterproof - unlike native plants that count on the cold to break the seed dormancy. Now some tender plants may have seed that can survive northern US winters but most in my experience do not.

FataMorgana

FYI

I stumbled across this post. It is hardy in zone 10 and 11, but treated as an annual in colder climates. It won't survive the colder winters.

I am hoping to grow this in zone 7a. Cannot find how long the growing season is, but I did find out it won't make our winters and is treated as an annual.

Since this original post and my answers then, I've grown jew's mallow quite successfully in Western NY State. I harvested the greens for use early on in the season and let the plant grow after that. Pretty yellow flowers. If I had let it get bigger earlier, the seeds probably would have had a chance to mature. But they didn't quite have enough time before the killing frost. Even after harvesting regularly early on in the season, the plants still got to be 4-5' feet tall. Someone in zone 7 should have no problems growing it. Just direct sow when you would plant your tender items like tomatoes in the garden. That's what I did.

FataMorgana

Thank you for that, Fata!