Will onion sets overwinter in USDA zone 4?

Question

I have garlic, and ornamental onions and chives planted. They overwinter, how about those bargain onion sets I bought? I planted the bag of twenty or thirty but it was a dry summer and those I harvested were not much bigger than when I put them in. They died down in the summer and the ones I left have started new foliage.

I don't know what kind they are but they look like a

Yellow Onion, also known as a Brown Onion, is a variety of dry onion with a strong flavor. White inside, its layers of papery skin have a yellow-brown color.

If I leave them in the ground will they over winter and grow again next spring?

what do you mean over winter, you mean you have onions that you didn't harvest this year? — Grady Player, Oct 24 '12 at 23:22
Any idea what variety they are? I believe the more onion-y varieties are hardier than the sweeter ones. — Niall C., Oct 25 '12 at 02:15

score 4 · Accepted Answer · edited Apr 13 '17 at 12:42

Onion sets are already in their second year, and onions are biennial, so even if they survived winter, it seems unlikely that they're going to get any better than they already are now.

I had onions grown from seed accidentally survive (I missed a couple at harvest time last fall) through a very mild winter last year in what is normally Z5. I would not expect onions to normally survive a cold winter -- especially with a lot of freeze/thaw cycles.

In your situation, I might harvest most of whatever is there and hope for better luck next year. (I'd probably also leave a few to see what happens -- just for curiosity sake. Deep mulch might help survival. I wouldn't expect much extra growth.)

and the answer is yes, they will overwinter if they do not set flower their first year — kevinskio, Sep 29 '13 at 19:48

Will onion sets overwinter in USDA zone 4?

1 Answers1