Yes and no. You can plant them and they will grow. However, if it's a bulb already, the next big growth spurt will be to produce a seed stalk. The bulb then will not only not grow any bigger but it will become smaller and eventually almost disappear into the base of the stalk.

If it's a green onion, then it depends upon the variety. Many scallions are actually thinnings from sweet bulbing types. If they have roots and are planted, it's just like planting any other onion plant. Those should then produce a bulb if planted at the normal time for the variety.

Martin

thanks for the info.

I have read where if you cut an onion in half and plant the bottom half cut surface over the dirt, it will sprout lots of mini onions. I have tried this with two varieties so far and have only gotten the one center onion to grow. I have not given up on it, and as time progresses I will try it with more varieties.

I would love to know what varieties produce bulblets for you. Plants that reproduce vegetatively as well as by seed are much more stable for hybridization!

Someone on the vegetable forum is. He has a rather long thread going too. He went dumpster diving for greens to put in his compost and found some really good looking sets that he decided to plant instead. You might want to check it out.

kristiina

I have onions growing that were started from the botton 3/16" that I trimmed off of green onions. I understand that you could also cut this small portion into sections and it will grow (next experiment)

I have white onions, with about ten inche stems growing from them...I am going to throw them in the ground and water them, am I wasting my time LOL...anyway,..just curious..

As a joke I bought two bundles of green onions and planted them one year and had excellant results.

Hey, cool...now I will try to do the same LOL...thanks for that!

I think I will try it too. I would like a seed onion

I got a bunch of big overripe onions recently from the market. They have all big green sprouts growing out of the tops. Can I cut the onion in half and plant the sprout portion or the other half?

I've considered planting cippolini onions from the store for seed - but at $2.50 for half a dozen little onions the seed is actually cheaper. Sometimes bulbs in the market have been treated with growth inhibiting hormones or irradiated to prevent them from growing, which ensures that they rot rather than grow.

I've planted garlic and elephant garlic from the grocer and both worked well. Shallots I've tried 3 times to complete failure (shallot sets produced universal success) so I think shallots are usually treated somehow to prevent sprouting.

First of all, it is too late to plant onions(from sets) in zones 7 and higher.
Second, if you plant a big onion(sprouted already or not) it will grow
lots of shoots and one scape that will grow flower and seeds.
But even if it did not flower, you will get just one onion.
I buy small pearl onions and plant them. The smaller, the better for planting.
But You have to do that 8 weeks before your last frost date or earlier.

Sure, you can plant store bought scallions if they sell them 25 cents a bunch.
For best results smaller ones are better. Keep atleast two inches, bury one inch in the ground.
You can go the same with leeks, to use the green like chives. You cut, they will grow back.

At the minute I have an onion that is sitting in a small
see-through vase, so far so good. It has grown
roughly 50-60 roots and they are still continuely
growing. All I need to know is....
What will this grow into?