I have property in NW WI and I planted 5 paw paw trees. I had heard that there's a paw paw in Madison so I had hope. I bought them from a tree farm in MI that said they had discovered a cold-resistant paw paw.

One of them survived over five years now! It's still really small but I think it'll make it. Even if it grows up there's two problems - the summer may not be long enough for it to produce fruit. And two, they reproduce by sexual reproduction. The only way it will produce fruit is if there's another paw paw in the vicinity.

I wanted to plant another batch of trees but when I went to the website of the tree farm there was an announcement that they retired - that they ran the farm for 50 years and it was time to retire. So no more cold-hardy paw paw.

I live in Zurich which is about the same latitude as NW WI and there's a bunch of paw paw trees at a tennis club near my house. They produce copious amounts of fruit. And there's constantly random new paw paw trees sprouting up. But the weather is much nicer here.

Maybe some day the weather in NW WI will be mild enough to match Zurich.

May be worth reaching out still :)

The commercial operation is retired but they may still help an enthusiast.