I have no idea. I grow winter onions, bu I am in an area where the ground does not freeze. They are also grown in the Pacific northwest zone 8. The key is "ground does not freeze". I looked at Michigan States Onion growing blog and it does not mention overwintering. You should contact your extension agent or Michigan State.

They grow in my zone especially if heavily mulched. But then my ground doesn't freeze like yours does. My best guess for you is no they won't.

Dave

Two years ago I grew Keepsake from Territorial, marketed as a winter onion. It grew in a tray starting in late August, then in a hoop house starting in October and produced nice-sized onions in late May. It was an unqualified success and I tried to get a large packet. Alas, they had discontinued it. Here in SE Michigan the climate is very similar to the OP's. I do not know if it would have survived without cover, and the ground did freeze under the hoop house, but they were certainly a lot hardier than regular onions.

When the experts (farmerdill & Dave) have spoken : Thanks gentlemen.

I am in PNW and have started a batch from seeds already. But I am aiming at bunching , not bulbs, Because, growing onion bulbs is just over my head. I have to figure out short day, intermediate day, long day ... and on top of that where the heck to get seeds from and, when to plant.... So all I am interested in is bunching onions. I tried once when I was in GA. They overwintered ok but did not bulb well, BECAUSE IT WAS THE WRONG SEED. I have come to realize that growing onions is more difficult than one might think. I also tried from set, from seedlings, ... nothing good to write home about.

Regardless if they will survive the frozen ground, your onion sets are probably not "overwintering onions" which are specific onions bred to tolerate some cold and then bulb in late spring. If regular long day onions are wintered over, most will just bolt, rather than bulb.

Most likely, if you plant those sets this fall, you might have some nice green onions to eat before they freeze.
-Mark

if i planted them this week, i could get some green onions before the freeze? thanks Dave, and farmerdill, your answers were much more clear than the one i got in the onion forum, at least to me.

If you plant them an inch or so apart, you should get some good sized green onions (scallions). Assuming the sets are still solid and not mushy.
-Mark

thanks mark for the answers. will i have to do anything other than put then put the ground this was going to be my 1st go at onions. or do i have to hill the dirt up around them?

I think just plant them about an inch or two deep or so and hope for the best.