It does the ring-thing all by itself--even when I remove a stem. There is a quarter in the pot for sizeÃ¢ÂÂ¦oops, the picture rotated...
I agree with Penny on your other thread... what you have is most likely a bunching onion (Allium fistulosum). Bunching onions are non-bulbing, and multiply to various degrees. This is a first-year plant of "Welsh" (also with a quarter for size reference).
Walking onions, bunching onions, and multiplier onions (potato, nesting, and shallots) all multiply from the base to varying degrees... but in my observations, walking onions don't usually have stems of that width. You will be able to make a more positive identification in Summer - either they will begin to bulb up, or they will flower without doing so.
Wow, your onions indeed look good. Just wondering, should I have planted my onions in deeper? Yours does not show the white stems. Also, I do not live in a climate that has a winter. It is summer, wet summer, a little cooler summer, windy summer, and just summerÃ¢ÂÂ¦Low elevation, Hawaii ;)
I believe the Asian bunching onions are hilled up as they grow, to get those long white stems. Never done that myself, I'm happy to use them green. As I mentioned though, the plants above are first year, from seed. In the second year, new shoots will emerge fairly high in the old pseudo-stem. When they start to look tired, you should be able to get fresh shoots by cutting off most of the growth close to the ground, and letting them re-sprout.
Hardiness is obviously not an issue in Hawaii... but there are differences in vigor between bunching onion varieties. In my observation, the larger the stem, the less likely it is to multiply, or to bounce back from pruning. Conversely, those with the smallest stems (like the variety "Four Seasons") multiply like chives, and are hard to kill. I've had my best results with some heirloom bunching onions (varieties "Franz" and "Stevenson") that had stems about 1/2-3/4" wide; they had the best compromise between hardiness, size, and multiplying ability.
Cold is part of an onions life cycle, I'm really curious how they behave without a period of dormancy.
I too am curious about the behavior of onions without cold weather. Hawaii has many microclimates and in certain areas we do grow regular onion (Maui onion from the yellow granex type?). Growing bulb type onions in these lower elevations, however; have not been successful for me. On the other hand, I hope to order some seed from the potato onion grower Kelly Winterton and try out that variety. I do have some small bulbing, multiplier-type very similar to I-itoi. The issue for me with the small purple one is, well, the sizeÃ¢ÂÂ¦Will set up a photo soon so that you can take a look and maybe have a real name for it. Thank you for your interest.