I would be guessing here, but they are probably walking onions. If so, they are OK in the ground all year and each year they will make a small bulb at the top and when those fall over they create more onions. The ones I have are quite strong and I don't usually use the onion, but I cut the tops and use them in a recipe in place of green onions.

I dropped some on the grass when I was getting mine ready to plant and they came up there. A neighbor wanted some so dug up one bunch, but the others are still growing in the grass and spreading out every year. One year the chickens ate the ones in my garden down to the ground and they still came back in the Spring. I don't know about keeping them in a pot though.

I think several people on the Forum have them so you will probably get some more answers.

I do think they likely are some form of multiplier onion, known variously as walking onions, potato onions or Egyptian onions. Shallots are very similar in growth. If so, they form small bulblets at the top that give you onions for the next season by rooting into the ground when the green tips of the foliage bend down far enough to reach the ground or by dropping seed from those seedheads/bulblets. They are very cold hardy and once you have them, they pretty much last forever.

They also could be perennial bunching onions, which generally are cold-hardy down to zone 4 or 5. With bunching onions, when you dig them up to use as scallions/green onions, you just leave a few and they multiply on their own. In that sense, they too are self-perpetuating, albeit with a little help from you.

These types of onions are grown and used as scallions or in a method similar to shallots, or used as shallots if that's what type you're growing.

As far as I know, all of these types of onions are winter hardy as long as they are not sitting in perpetually wet, swampy soil with very poor drainage.

I planted "Gumbo" perennial onions in early autumn. They are a perennial onion from Louisiana.

I've linked a page from the SESE catalog that has cultural notes for multiplying onions. If you look at their page that features multiplier onions and shallots, you'll see the descriptions for a few of the varieties of multiplier onions that are available commercially.

Here is a link that might be useful: Perennial Onions

I too thought probably Egyptian onions (called winter onions by the aunt who gave them to me.)which I have had for 30 years or more. They sail through heat and cold. But the perrenial bunching onions I started a year and a half ago died out in this summer's drought. I didn't water them because I never had to water the Egyptian onions or the garlic that I have to keep them alive.

The Egyptian onions are stronger than annual green onions, but I have dug whole clumps in the winter to add to stirfry, soup, spaghetti etc. They're too strong for our taste to eat raw

Thank you all so very much! I know that the ones she had growing up are the Egyptian type, and she wanted something similar so that is most likely it.
I live near to where she grew up and we still have th onions every year. Do you think they will be OK in the barrel maybe if I mulch them? The barrel is somewhat sheltered on the south side.
Thanks again!
mo

Mo, I think they'll be fine in the barrel, mulched, as long as we don't have one of those record-setting cold spells with temperatures 30 degrees below average or something like that in the winter months. If that happens, I'd throw a blanket over the entire barrel during that cold spell. If that cold spell were to be accompanied by snow, the snow would give them additional insulation from the cold temps.

Dawn

Thanks Dawn. that is what I will do.
mo