Stop right there! Were you going to throw those green onion ends in the compost? Stick them in a jar of water instead. The Burlap Bag demonstrates that you can re-grow onions indefinitely with nothing but a jar of water.
1. Choose green onions with longer roots at the store.
2. Cut the onions to use as you normally would, saving the white end with roots.
3. Place the roots in a jar of water in indirect sunlight and wait for them to spring up again!