I do not know if I have mentioned to the beginning gardeners in the bunch, but any part of an onion that contains the central growing (parental) parts are capable of growing (cloning) a whole new onion. Never throw away the cut off partts of an onion you have used, just set them in the ground.
I rarely allow them to mature, since I love green onions so much, but NEVER throw away or waste a cut off onion part. They will make fabulous "free treets."
Just set it in the ground (top or bottom, both will grow well - just do not mix up which direction it naturally grows. Many perfectly viable cut-offs from mature onions will die if they have to "play roll-over" when you put them in the ground upside down. That would be a fuck up) and in a bit of time - green onion sprouts!
