Lawn and Garden

How to Trim Your Lawn

Lawn + Garden Projects

How to Trim Your Lawn

Print Page

Trimming is a finishing touch to mowing your lawn. You are simply cutting those areas the mower can’t reach, such as grass around trees and fences. Try to cut the grass as closely as possible to the way the mower cuts. When you’re trimming with a string trimmer, concentrate on keeping the head of the trimmer at the same level the grass was mowed. You can, however, use a slight downward angle to improve sightlines.

It takes a lot of concentration to cut clean level lines with a string trimmer, but don’t lose sight of safety issues. A trim line spins at a high speed and it can catch rocks, small toys, and other yard debris, flinging them a long way at a high speed. Keep an eye out for any surprises hidden at the borders of the lawn, and don’t trim when there are children present.

Your lawn will look its best—and you’ll keep the grass at the fringes as healthy as possible—if you trim every time you mow, regardless of whether the lawn appears to need trimming. As an extension of mowing, trimming has to follow the same rules; you don’t want to take off more than 1⁄3 of the height of the grass you trim if you can help it. You can also use the trimmer for light edging work, basically to square up light overgrowth. Simply turn the machine so the head is vertical (some units have swivel heads for just this purpose).

Finish up trimming by checking the trimmer head and housing for any debris or damage. Replace the spool or wire if necessary; there are several different types, so follow the manufacturer’s directions and replace like with like.

Using a String Trimmer


Before you start, inspect the trimmer for any damage and determine if the string needs to be replaced. For electric trimmers, inspect the trimmer’s power cord to make sure it is in good condition—the cord casing often is damaged accidentally by the trimmer string.


To trim edges and vertical spots such as along edging or next to a wall, angle the head of the trimmer slightly downward toward the surface. Trim slowly and steadily in a line.


To mow small areas that the lawnmower cannot reach, keep the trimming head level at the same height as you mow the grass, and methodically cut all the grass in the area.


Trimming is all about looking neat and tidy, so you don’t want to leave clippings laying around loose. A quick pass with a cordless blower/vacuum will suck up any loose clippings and keep the house and lawn looking sharp.


OPTIONAL: You can edge with a string trimmer by holding the head at a 90° angle to the ground. Carefully move along parallel to the line you are edging. Because the trim head and string will be exposed, make certain there are no people or animals nearby, and wear eye protection.