I have never heard of them, so I googled. They sound interesting!

I think they would probably grow well in Z-7.

Here is a link that might be useful: Crosnes

I grew them once when I lived in SoCal... can't remember where I got the stock. The gophers really loved them, only a few plants survived. The yield from those plants was not impressive, and the tubers were small & very difficult to clean. I gave away what little I had, and never grew them again. Wish I could be more encouraging... it is an interesting plant, but there are other, more productive root crops that are a better use of space.

agree, they are tiny. Probably best trying mashua or oca, or even better, yacon.

Thanks for your replies.
I read a lot of thing about oca. And Oca is have to small yield. Maybe mashua would be better, but it's hard to get them. Mainly in europe this root vegetables are rare.

Kristianhun - if you put 'crosnes' into the search box at the top of the page you will find several old threads about them. Putting in their alternative common name 'Chinese artichokes ' also yields some threads.