How to use a grass trimmer

Knowing how to use a grass trimmer or brush cutter correctly is a simple matter of the right technique. You’re sure to succeed with our clear guide.

A man mowing flower meadow with FSA 57

Committed to your safety: protective equipment


Working with powerful tools is fun and means you can extend your abilities – which is great as long as you are relying on effective and safe protective clothing while using them. Always wear personal protective equipment when working with your chainsaw. This includes a helmet, cut protection trousers, safety boots, and more. The instruction manual for your product contains more details on this. Fully familiarise yourself with the tool before you use your grass trimmer for the first time, and check it is in flawless condition before each use. On request, your STIHL dealer will be happy to prepare your tool for its first use, and will also advise you on models and sizes of protective clothing that you can try at your leisure. Please remember that personal protective equipment is no substitute for safe working techniques.


A woman wearing safety glasses is trimming grass with a STIHL FS 240 with the shoulder harness

How to put on a grass trimmer with harness

Before you really get on with your grass trimmer techniques and use, you need to equip it properly. For efficient and comfortable work, it is important that the harness for your grass trimmer, brush cutter or clearing saw fits you perfectly, otherwise the weight will be unbalanced and the tool will be harder to use properly.

A woman trims tall grass around the edge of a garden using the STIHL FSA 57 cordless grass trimmer

How to use a grass trimmer: basic technique

With the right technique, you can achieve amazing results with your STIHL grass trimmer. Even if this is the first time you have used a grass trimmer, the basic technique for cutting an area of grass is simple and quick to master: just swing the power tool in a semicircle from right to left, while slowly moving forward. One advantage of this method is that it means the cuttings fall onto the mown area.

A woman wearing face protection uses a STIHL FS 240 grass trimmer in long grass beside a lake

How to use a grass trimmer in tall grass

If you have very tall grass or weeds to deal with, we recommend a two-step approach. First swing your grass trimmer from left to right at a higher level, to cut the top of the grass or weeds; then sweep back in the opposite direction close to the ground, to complete the cut. The cuttings will also fall to the left.

Person mowing large area of level ground with a STIHL FS 230 grass trimmer

How to tackle grass trimmer tasks in large areas of level ground


Our Tip: The best way to approach a large grass trimmer job on an even expanse is to use the quadrant method. Just divide the area into smaller manageable sections, and work from the outer sections to the middle. This is a methodical approach that will give more consistent results.

A person cutting grass on a slope, working in strips with the STIHL FS 240 grass

How to use a grass trimmer on hills and steep slopes

If you have to use your trimmer to cut grass on hilly ground, we recommend the strip method. The key here is not to work from the top to the bottom of the hill; this is less safe as well as likely to give untidy results. Instead, work with your grass trimmer in a strip across the slope. At the end of the strip, turn around and cut a strip above the first. This approach will also keep cuttings in the mown area.
Close-up of a STIHL FS 240 grass trimmer cutting close to the base of a tree

Dealing with obstacles: grass trimming borders

A string trimmer is the best tool for trimming lawn close to trees and shrubs without damaging the plants. If you have several trees close together, you may wish to trim a border into the grass around them before you mow the lawn. You can use the guard of your grass trimmer to make sure the border is neat: keep the guard against the trunk as you move the trimmer around the tree. You can use a similar method for trimming grass along a fence.

Important note

Please always read the operating instructions for your power tool. You can download the instruction manual for your STIHL grass trimmer here. Your STIHL Approved dealer is always happy to offer advice on usage too. 


Summary: how to use a grass trimmer

  • Always use personal protective equipment according to your power tool’s operating instructions
  • Get the basics right: make sure you put on your grass trimmer harness correctly for comfortable and efficient work
  • Most people sweep the trimmer from right to left
  • It is best to cut very tall grass as you sweep in both directions, in two stages
  • Use the quadrant method to work in large areas
  • For the best results and optimum safety, grass on a slope should be cut in strips going across the gradient
  • Use your grass trimmer to trim easily around obstacles in the lawn