Onion sets - Year 2

I was late planting onion sets this year and they didn't grow much. When I pulled the usable onions I missed a lot. They were so small they'd disappeared. Now they're shooting!
My plan is to leave them until next year and see what happens. Logically, I would expect them to flower/seed which got me thinking - could I create a permanent onion bed in the same way as I'm trying to do with leeks and spring onions. 
Does an onion split into two with side bulbs or does it die after flowering?
What if you remove the flowers - would it bulk up?

All this and more I need to know. Can anyone help please?

No. I chop the top off flowering sets and dig up the leftover ones. Although I do have a leek (I think) cowering in a corner from a very late transplanting year before last I think. Its not very big and will probably go to seed and get dug up as it'll be in the way - that's why it's frightened.

Leave that poor leek alone -don't be such a bully!

Onion sets and bulbs, in the first year, can produce large bulbs despite flowering. My Autumn ones last year that flowered kept quite well and just had a dried stem in the middle. The spring ones from seed that flowered still produced sizable bulbs but were unlikely to keep very well as the stems in the middle kept quite wet and would have rotted quickly if not used. Some year old large bulbs I planted specifically for seeds, used up all the bulb in the second year producing the seeds. Some others I'd tried last year to unsuccessfully get seeds off that flowered, 2 of the 3 died but the other formed some small bulbs that could have been regrown but I didn't bother.
Should be interesting to know how your onions get on.

Update!
I used a few of the second year onions for cooking - like fat spring onions. Some I left to flower and look what happened!

         

The seeds are growing on the flower head - a bit like Vinny's leek hair.   If I have the patience, I'll pot some of the seedlings up but there'll be more clumps left to do their thing in the ground.

What you have there veggie is a clone of the original onion. So my logic would determine that if the original onion was puny and went to seed early.so will the clones.

I have never done it but I understand that as with leeks, the large onion growers that grow for shows grow their onions from clones (grass,pips,pods) of their best show winning onions.

To be fair to the puny onions, they were part of an enormous batch of onions that I was sent by ?DTBrown as an end of season offer - at least double what I'd ordered. They sat around in trays for weeks until I squidged them in between some strawberry plants so they didn't have a healthy childhood.

Found it!!
01-04-21, 14:08
I ordered some onions sets from DTBrown with their special BOGOF offer - buy any 2, get the cheapest free.
A 250g bag of sets = approx 80 sets so I expected to grow about 160 onions this year and that's going to be more than I need..

They've just arrived with a little note -
"As we are getting towards the end of despatches for onion and shallot sets, you may find a few rotten sets within the pack. This, unfortunately , is unavoidable at this time of year, so to help compensate for this, we're enclosing another pack to ensure you have plenty of quality sets to plant."

Space needed for 320 onions!!!
Can't fault DTBrown's customer service. Smile

PS They all look fine - no sign of rotting or sprouting.

I can’t help at all. I’ve been waiting 2 years for some spring onions to go to seed!   
I’ve got some shallot seeds drying at the moment. The sets I left in the ground were a decent size. So fingers crossed the offspring will be just as good.

A 1943 timelapse film of the Life cycle of an Onion just popped up. https://www.youtube.com/watch?v=nWwMKy3vE44&t=1s
Worth a watch!

Before you ask, I wasn't around at the time but there is a name I recognise on the title page.

A 1943 timelapse film of the Life cycle of an Onion just popped up. https://www.youtube.com/watch?v=nWwMKy3vE44&t=1s
Worth a watch!

Before you ask, I wasn't around at the time but there is a name I recognise on the title page.

Love it. Enjoyed that and very informative although it doesn't mention vegetative propagation.