1. Lay out a hose on the lawn, adjusting it to the outline you want the new bed to have.
2. Using a sharp, square-bladed spade, cut through the sod just down to the soil surface, following the hose outline. Work the spade under the sod and lift it off, a shovelful at a time.
To make removing the lawn easier, you may want to kill the grass first, by smothering it with black plastic or a 1/4- to 1/2-inch-thick layer of newspaper or cardboard. Anchor the covering in place with bark chips, bricks, or rocks. If you lay down the covering in midsummer, the grass should be dead by fall. Remove it then (in mild-winter areas) or the following spring (in cold-winter areas). Then continue to prepare the new bed.
3. Once you have removed the grass, cultivate the area and work in amendments. Then plant as desired.