Not sure I understand. You harvest green onions long before they try to flower.

No, these are perennial bunching onions. My plants are close to 30 years old. They spin off new "scallions" from existing ones, splitting along the side of the plant and you just cut off the ones you want a little below the surface. Each original plant eventually makes a good sized mass and you can cut off "scallions" as you need them. Every spring they want to bloom, but as I said, except for this year when they just won't stop, you cut off the bloom stalks and the rest of the clump goes on producing new scallions.

Just google evergreen bunching onions and you'll find out what they are.

I see. Bunching onions are sometimes identified just as green onions. But they seem to be a little more than that. In general, bolting in onions is caused by stress. Did you have a hard winter/spring? All plants try to set seed if they think they're about to expire. Dixondale says a cold, wet spring followed by a hot summer can result in bolting.

30-year-old clumps! You have done a good job! I don't know, maybe temps have been warmer? A buildup of pests or diseases in the spot? I would start some new clumps and see how they do next year.

Bunching onions are a different species from Allium cepa. Strange that an onion expert like Dan has not heard them since they are commonly sold, and I think he has posted on threads about them in the past.

We had a winter somewhat colder than we've had in several years, but I've had them when they went through MUCH colder winters. Spring weather has gotten crazier and crazier with summer temps this year in March then back to spring then summer temps and a plunge to the upper teens, which hit the garlic especially hard. But the bunching onions seemed not to be too hard hit. In any case, spring wasn't cold and wet and summer is just starting here. But they're still sending up bloom stalks.

Really disappointing.

I don't claim to be an onion expert. But thank you for the compliment. I've never posted any threads on bunching onions. You are mistaken. Bunching onions are often confused with regular green onions. https://ucanr.edu/site/uc-master-gardeners-santa-clara-county/green-bunching-onions

I grow the evergreen bunching onions, never tried to keep past flowering. I pull up and use green and white parts. I bet the warm / cold temperature swings is what is messing everything up,.

Dan- Bunching onions or welsh onions are a fun to grow non-bulbing, clump-forming perennial onion that multiplies via division. Think of them as giant chives. Being perennial they're gonna flower every year regardless of what type of winter they endured. What's odd is that clipping the flower off has resulted in them trying to flower again...

Laceyvail- If you'd be willing to share a few of your bunching onions I'd gladly pay postage. Several years back I lost many of the perennial alliums I used to grow and I'm currently in the process of re-acquiring them.

Rodney

Rodney, I think you'd have better luck just starting new ones from seed. My patch is very small, and to send even a few, especially now that they're not spinning off more, would leave me with just too few. Seed is readily available from many sources.

My biggest problem with all my alliums is that the alliium leaf borer arrived a couple of years ago, leaving me with having to cover them March/April and again Sept/Oct. The latter includes only the bunching ones as the others are harvested. The jerry rigged set up I came up with is very difficult to maintain--always collapsing-- and rain makes it even more difficult. Oddly enough, the borer seems to have no interest in ornamental alliums, readily available not very distant.