So, we have a regular purple onion with a 3-inch green stalk shooting out of the end. We dug a hole and put the onion in the hole. This won't work right? I guess it's already grown. Will this provide a seed for future growth? Was this all just a silly exercise in hole building?
Planting Sprouted Onion
Certified GKH Gardening Expert
You won't end up with new onions, but, yes, you may end up with seeds or bulblets (seed bulbs attached to the mother plant you can plant next year).
Also, many alliums (onions and relatives) have a lovely flower. You may find it very decorative.