A nice crisp edge on a lawn looks great. In this case, the edge is cut into the lawn with an edging shovel, creating a mini ditch several inches deep. The reason this works is that grass roots will die if exposed to air. Eventually the little ditch will fill up with leaves and soil, and the grass will grow back into the lawn. An edge like this needs to be re-cut 2-3 times per year. On a small lawn, this is not a lot of work.