Encouraging onions to sprout but not rot.

I get a lot of onions from dumpsters.
We chop them up and freeze them, and we cook with them later.
I take the sprouting onions and cut out the core.
This allows me to plant the onion amd use the onion.
I want more sprouting onions for planting, but I don't want them to rot.
I think maybe I should put them in the fridge , but I want to see what yall think.

Hi William,
Interesting idea. They might have less energy to start their growth if you cut off the edges, but its a cool way to use it and grow it.

Like most things, onions need the right conditions to sprout, and the opposite should help make them last longer before they sprout?

I think onions like warm humid light conditions to sprout. So maybe dry, cool and dark?

Your response got me looking into ideal storage conditions which are cool, dry and dark.
Moisture encourages sprouting and rot, so a fridge is not good.

Based on this, think I'll try warm sunny and dry, so probably spaced out on a wire shelf.
A wire mesh cupcake baking tin would be ideal 😋

Not all onions store well.  My storage onions are still doing just fine from last year in my dark, cold and somewhat damp root cellar.  Walla walla onions seem to keep for about two weeks before going bad.  So the variety you get may significantly impact your success.

Interesting!
This last batch looked different.
I was wondering if they were sweet onions.
They went from the dumpster to a cat litter bucket, with a lid.
It's 86 degrees here now, I think id better air them out today...

At one time I wondered if I could grow more onions out of the big bulbs. I carefully removed the usable outside layers to reveal the core. I also put the cores in water to encourage root growth. Usually there were more than one plantlets and they could be splited before planting. The plants grew very well but never formed bulbs due to unsuitable day length and temperature conditions. Nevertheless I harvested lots of greens before frost and used them as bunching onions.

Most ordinary onions will be inbreds sprayed with cides and used to being bathed in nitrates. I doubt you can provide these cirumstances in your garden. Why not propagate genetic sound onions like Egyptian Walking onions or Potato Onion.

I've gotten great results from previous iterations.
I have some walking onions, but they are not propagating quickly.
Just ordering potatoe onions has proven problematic in the past .
I haven't given up on them but I  focus on the plants I have in hand, not on theoretically ideal plants that are hard to get.
I literally eat onions from the garbage, I'm certial not very picky about contamination.
Using the core of an onion to grow more food is an nature extention of my frugality.

When you brought up sprays, it reminded me that they might been cover in sprouting inhibitor.
I might peel the outer layer on some, since they are just sitting there seemingly inert.

May, I've done the same thing with similar results.
It's kinda a lot if work.
I've also planted just the bottom third and gotten bunching onions that never got very big.
That was easier, but wasted more onion.
I'm trying to acheive the same outcomes with less labor.
Green sprouts have pretty much guarantee good results.
Seeing your photo, I want to try my "coring" , and then lift layers off the toptill I get to an uncut layer, just like you show, but with less fuss, hopefully.

I "cored" an onion and set the core out with the rack of whole onions.
I was hoping it would sprout, but after a week or so, nothing.
Another of the onions did sprout, so I clearly have not figured this out, so tqoday I cored the rest of the onions and I will plant them out tommorrow.

The cores won't sprout and will dry out if not dip the end into water. Change water daily and new roots will grow. Since the cores don't have much nutrition left, once the root tips are showing I would plant them in ground.

When I planted  the cores out today I checked in the previous batch.
It was good news.
The cores I planted have sprouted.
I even divided ome of them, since they had multiple shoots.
I had also planted the butt end of some onions, and even though they were little more than the disk of roots, they had also sprouted.
I think the butt end of onions will more reliablely create multiple shoots/bulbs.
I did bury them too deep given that they have little in yhe way of reserves, so I relocated them to the surface.
I might try starting them in trays instead of starting onions from seed.