Warning: This is a 4-steps wacky way of planting green onions. If you are the skeptical type, either don't read or commit to trying it for yourself.
Step 1: You dress up for garden work
Step 2: You buy a bunch of green onions with their roots showing up. Chop those roots off and keep aside.
Step 3: Bury the roots in the ground. Give it a few weeks and see green onions grow.
Step 4: Recycle - once you pull one out of the ground, chop its root off and put it back in. You'd never be short of green onions.