If one plants an onion, does it produce more bulbs under the surface or does it remain as a single bulb?

“And, as long as you have another onion on hand, you don’t need to grow them from a seed.
By chopping the bottom of an onion off and planting it in soil, you can grow your own onions from cuttings. With patience, time, and plenty of water, you can grow an onion from an onion in 90–120 days.”

How to Grow an Onion from an Onion: 12 Steps (with Pictures)
https://m.wikihow.com › Grow-an-Onion-from-an-Onion

It depends on the species of onion like shallots etc

@lucillelucillelucille
Found this online , perhaps it is a better answer to your question?
Reasons for No Onion Bulbs
“One possible reason for a lack of onion bulb formation is the selection of the wrong type of onion for your area.

In their natural environment, onions are biennials that have a “two-year life cycle.”

The first year, the plant bulbs and the second year it flowers.”
No Onion Bulbs – How To Get Onions To Form A Bulb
https://www.gardeningknowhow.com › edible › vegetables › onion-bulb-for…

@Inspired_2write -Thanks for that. The link above is broken.
I did try to grow them one year (not by the way i mentioned) and they did nt come up.
Garlic has always produced a smaller bulb (by just planting a clove about 4” down) but good just the same.

My husband once planted onions. Come fall he mowed the yard AND the garden. It threw onion pieces all over the yard. The next year, onions everywhere!
When we go on walks with the kids we find bunches of “wild” onions all along the way.

@lucillelucillelucille

My older brother tried to grow garlic and stated that the first crop is to produce the seeds that one harvests for the second crop. ( apparently it produces a pod full of seeds to plant)

He is very knowledgeable about garlic now..lol

@Inspired_2write -I haven’t tried it from seed but they do produce a flower similar to alliums. I believe they are part of that family.
What surprised me is that the leaves are very garlicy as well.
@Dutchess_III -lol! :)

@Inspired_2write -I haven’t tried it from seed but they do produce a flower similar to alliums. I believe they are part of that family.
What surprised me is that the leaves are very garlicy as well.
@Dutchess_III -lol! :)

@Inspired_2write garlic is grown from garlic cloves, not seeds. The cloves one uses to grow the garlic can be called seed garlic.

”...The flowers of garlic plants usually fade long before producing any seed. Of course, plants produced using garlic seed propagation are not likely to grow anyway and those few that do will take years to produce any garlic.”

@Dutchess_III
oh no wonder its taking a long time for his plants to grow..lol.

To answer the question…as far as I know it remains as a single bulb.