Saving pennies - green onions

I heard that you if put the root ends of green onions back in the ground, they'll grow back. So I did. And now I've got little green shoots so it looks like it is working. Actually, I'm not doing this to save money. I'm doing it because it will be so much more convenient to go out in the backyard and pick what I need rather than buying a bunch and trying to use them before they go bad.