Once an onion has sprouted, there’s nothing wrong with eating it. Provided it’s not actually spoiling or molding, it’s still fine to cut up for dinner. The problem is, there isn’t much usable onion inside at this point. Rather than trying to eat it, it’s better to invest in a good crop of future onions. If you can plant it, you’ll reap a reward 3 fold by the end of the season.
Onions are usually grown from seed, and a sprouted onion need to be divided to grow properly. After the first growing season, if that onion had stayed in the ground instead of being harvested, it would have divided into multiple onions all on its own. Each individual onion would be a bit deformed, as it competed for space with the others. By separating them, each onion can grow into a full-sized bulb, and allow you to harvest far more than you planted.
Start by peeling back the outer paper of the onion. Once inside, you’ll see that the onion has already started to section itself off into multiple onion plants.
Once you’ve peeled everything off, you should have multiple distinct onion sprouts.
How to plant the sprouted onions
Once divided, sprouted onions can be planted directly into the garden or potted up indoors.
Onions are pretty easy to grow, but they can’t handle weedy competition and they need ample water in well-drained soil.
The time to harvest your new, fully sized onions will depend on how big their initial bulbs were at planting, and the onion variety. Generally, sprouted onion plants give you a head start on the season as compared to planting a seed, and gardeners harvest onions from started onion plants about 65 to 80 days after planting.
Keep an eye on your plants, weed them regularly and water them every few days. Soon enough, you’ll have several onions to replace that sprouted onion from your pantry.