You use a string trimmer to finish your lawn. This ensures that you also keep the hard-to-reach corners tidy, which you can't easily reach with a lawn mower. You can choose from a string trimmer that works on electricity, a battery, or gasoline. An electric string trimmer is often more affordable, but you need extension cords. A battery-powered string trimmer provides more freedom of movement, but you are dependent on the battery life. With a gasoline string trimmer, you can rid your garden of stiff grasses and weeds. These models have the most power, but require a lot of maintenance.