1. You can get great drainage for the soil, especially good for me in south louisiana where we have swampy ground.
2. You can start your garden off with great dirt rather than slowly building up the natural soil over several years.
3. The weeding is slim to none! (That's a good enough reason right there!)
First, lay out the dimensions of the garden. My extension will be 5 feet by 5 feet. You don't want to make it wider that 5 feet, otherwise you won't be able to reach the plants in the middle unless you make rows, but those waste too much space in a small backyard garden. Once you have decided on the size, mark out the area on the ground and use a flat shovel to dig up the grass.