My Onions are flowering

My onions have started flowering. This is the first time that I've had this happen (unless I've missed harvesting a couple and the following year they flowered). They were started from sets this Spring. I'm guessing that that's it then for the bulb - no more growing? Can anyone explain why they did this so quickly?

The simple answer is probably because of "stress". This could be water, light, temperature, or some other factor. When a plant starts to feel stress, it can get into that mode of "this may be my last chance to seed!"
I usually cut these scapes for eating when I don't want any seed - that seems to help a little.

Sorry Eric, what is a 'scape'? Is it the whole onion or just the tops?

And yes, stress could be a factor now that I think about it. They were planted during a wonderful sunny, high temp Spring that they probably thought was Summer. Then they got deluged by rain for all of May and June that they probably thought was Autumn. Oh damn, I was looking forward to our whole year's supply of onions in storage this winter.

The scapes are just the green stalk in the middle that the seed head comes up on - the same for garlic, leeks, and other alliums.
You can cut the scapes any time before theflowers die and become seeds - I usually do it when they have one unopened bud and then sautee with some eggs or greens..

Try this first and see how the onions continue to grow -- if the rest of the greens die back, you can harvest the bulb or just leave it in the ground for next year (it will very likely return..)

Tell me what kind of onion you choose for growing?