Turfgrasses grow rapidly and aggressively in the South. If not edged back regularly, Southern turf will grow right over sidewalks, driveways, flower beds, etc.
 
In the northern United States, where Kentucky bluegrass is the predominant species, edging is necessary only once or twice a year; in the Deep South, you will probably need to edge every couple of weeks. You have several choices of edging tools for the job.

Non-powered Hand Tools
It is possible to edge with a shovel or a straight-blade edging spade. It will take a lot of effort but may be the best option for small projects. Non-powered rotary edgers are also available.

Walk-behind Powered Edger
The traditional tool for larger edging projects is a walk-behind edger. These machines have a steel blade rotating about a horizontal axis and are carried on a set of wheels. The wheels are run on the sidewalk or driveway and allow precise control of cutting depth. Power can come from a small gasoline engine or an electric motor. The gasoline engine models have more power and allow more versatile operation than electric models, but they are more expensive and require more maintenance. The electric models require dragging a cord, but they are inexpensive and low maintenance. These edgers are versatile, easy to adjust and control, and they do an excellent job.

Stick Edger
A more recent development that is popular with grounds maintenance professionals is the stick edger (Figure 1). This is basically an edging head mounted on the end of a string trimmer engine and shaft. Because they typically have only one wheel to carry the edger and control depth, a stick edger requires more skill than a walk-behind edger, but it is a simple tool that is easy to carry on a truck and light to load and unload. A professional with a stick edger can edge almost as fast as he can walk.
 
If your stick edger is the same brand and engine size as your string trimmer, you can use one can of fuel mix for both, and also stock interchangeable engine parts. Some string trimmers consist of a powerhead with interchangeable tools so you can change between a string trimmer head and an edger head on the same engine and shaft.

String Trimmer
A good alternative for homeowners is to use a string trimmer for edging (Figure 2). Just hold the trimmer so the line spins in a vertical circle. If you have only a moderate amount of edging to do and already own a string trimmer, this is your best option. A string trimmer is harder to control than an dedicated edger. Because there are no wheels or guides, you may not end up with quite as professional an edge as with an edger. Another negative of using a string trimmer for edging is that edging burns up trimmer line much more rapidly than routine trimming. Running against concrete chews up line rapidly, necessitating more frequent feeding and replacement. Electric string trimmers may not have enough power for edging.

Safety
Any edger can throw gravel or other objects with considerable force. Be sure to wear eye protection, and keep all bystanders well away while you are working. The debris is thrown in only one direction, but you really have no choice about which way to aim the tool since edgers have to be aimed in only one direction. An edger blade can be lethal. Be careful to avoid blade contact, and keep children and pets well away from the blade. Shut off the engine and remove the spark plug wire or unplug electric edgers before working around the blade.

If you live in the South and want a quality landscape, you will need to edge your turf where it meets sidewalks, driveways, etc. You have several choices in tools. For small jobs, hand tools are adequate. For typical lawns, a string trimmer held vertically is an excellent choice. For larger projects, consider a dedicated edger.