If you want to make your garden look neat and keep grass and weeds out, you will have to edge the garden from time to time. Garden edging is a process of removing grass and weeds from the perimeter of a garden bed to prevent them from spreading into the bed, either through seeds, roots or runners. There are a number of tools that are commercially available to help you with the task of edging.
An edging tool is similar to a spade in that it looks like a wide, flat blade mounted to a handle. Like a spade, the edging tool is inserted vertically into the ground. However, an edging tool's job is to break up sod that might be encroaching on your flower beds by creating an "edge" in which there is only bare dirt, and to make it easier to remove roots from this no-man's land between the grass and the flower bed.
A string trimmer is used to cut weeds in places where your lawn mower cannot reach. However, the trimmer can double as an edging tool if the head is turned up on its side and used at a perpendicular angle to the ground. Using a string trimmer in this way allows you to trim grass, low-growing shrubs or other organic material in a neat, perpendicular line.
A sod cutter is a tool designed to remove sod in an even strip down to the dirt. Sod cutters can be used to remove thatch from a lawn in preparation for reseeding the lawn, or they can be used to edge the strip of grass around a garden bed in the same way as an edging knife.
A cultivator is used in the garden to remove weeds. This type of tool consists of a set of wheeled tines that interlock as they roll. These tines are mounted to a head that is then attached to a handle. The cultivator can be worked through the soil by pushing and pulling it similar to a hoe and rake. Just as the cultivator can pick up weeds, it can also pick up the roots of grass and break up the soil around the edge of a garden bed.