You've probably been told to add 2-4 inches of mulch to your garden or to till in 6 inches of organic matter. Hard as tilling may be, the really difficult part is figuring out how much mulch or amendment to buy for your size garden. It's not rocket science, but it does require a few simple equations.

Don't be intimidated. Let me walk you through the steps here. Once you've mastered this technique, you can use it to amaze your gardening friends.