STIHL Profi Tip
Determine the gradient of the slope using your smartphone. To do this, first install a inclinometer app. Place a long board on the slope and put your smartphone down on it. This makes it easy to read the slope from the display.
Mowing slopes: how best to maintain your sloping lawn
When it comes to tricky terrain like sloping lawns, it’s all about the right tools and technique. Find out how best to cut grass on a steep hill or sloping lawn.
05.03.2025
Overview: mowing slopes
- Special care and attention is required when using a mower on a steep hill, bank, or slope. There is risk of injury!
- Inspect the slope in advance for soil condition and incline
- With the ride-on mower, you can work up and down gentle slopes of up to about 10 degrees or 17.6%
- When mowing across the slope, your lawn mower can cope with gradients up to 25 degrees or 46.6%
- Depending on the model, STIHL robotic mowers can mow gradients up to 24 degrees or 45%
- It is best to use a brushcutter on slopes with higher gradients
- Before use, it is essential to follow the instructions in the operating manual for your mower
Which lawn mower is suitable for slopes depends primarily on the type and gradient of the slope. Gentle slopes can be cut with almost all mowers. On the other hand, very steep slopes often require the use of a brushcutter.
Mow a slope slowly and carefully. Depending on the mower, you can either travel up and down or across the slope. Be sure to consult your mower operating instructions, and wear appropriate personal protective equipment for the job.
The challenge of slopes: Problems mowing slopes
Mowing slopes is doubly challenging for both user and machine. One factor is that occupational safety must be ensured at all times; another key consideration is that optimal mowing results also depend on the choice of work tool.
The most common problems with using a lawn mower on hills or slopes occur when the gradient is too steep. This can lead to loss of control of the mower and cause serious accidents. To ensure that you always have everything under control and are working safely, we have summarised what you should pay attention to when mowing a slope and which tools are suitable for mowing a steep incline.
Proper preparation for mowing slopes
To optimally prepare for the task, you should take a close look at the slope to be mown in advance, and familiarise yourself with the individual characteristics of the terrain. Pay particular attention to the incline and the soil condition, as using a lawn mower on a slope requires great care and attention.
Refer to your mower’s owners manuals for the maximum permitted incline. To ensure safe working, it is essential that you comply with this.
Also check your mower thoroughly, in advance. If you are using a mower with a four-stroke combustion engine, make sure that there is sufficient lubrication during operation. To do this correctly, consult the information in the user manual supplied with the combustion engine.
If your lawn mower is not suitable for mowing slopes, use a clearing saw. This means that even steep slopes can be safely mown.
Safety first: personal protective equipment
Working with high-performance power tools is fun and allows you to broaden your skills, which is great if you can rely on effective and safe protective clothing. Always wear your personal protective equipment when working with a ride-on mower, lawn mower or brushcutter. This includes a helmet, ear protection, cut protection trousers, safety boots and more. Find out more information in the operating instructions for your product. Before using your power tool for the first time, fully familiarise yourself with it and ensure that it is in flawless condition before each use. On request, your STIHL dealer will be happy to prepare your power tool for its first job, and will also advise you on models and sizes of protective clothing that you can try on at your leisure. Please remember that personal protective equipment is no substitute for working safely.
Mowing slopes: tips for every mower
The following tips explain how to optimally cut grass on steep hills and slopes for all common mower types.
Mowing on a slope with a lawn mower
Depending on the lawn mower model, the maximum permitted incline is usually between 17 and 25 degrees, i.e. between around 30% and around 46%. You can do everything right by following the tips below.
- Only move the lawn mower across the slope, and start at the bottom, especially on steeper inclines. This means that you are always turning uphill, which avoids the mower accelerating and you potentially losing control of it when it turns at the end of the cutting path.
- One exception is when mowing without a collection box. In this case we recommend you start at the top so that you do not slip on the fresh grass cuttings.
- With a manual push mower, there is also an increased risk of accident if you mow in an up-and-down direction because the mower can move uphill or slip downhill.
- To minimise the risk of slipping, only mow on a slope with the lawn mower when the grass is dry.
- For best grip, do not directly follow in the mower’s path, but walk a little deeper down and support yourself towards the slope. Mowers with swivelling handles and lawn mowers with wheel drive reduce the effort required and are therefore recommended.
Mowing on a slope with a ride-on mower
When using a ride-on mower for slopes or hills, for safety reasons the gradient must not be steeper than 10 degrees or 17.6%. Only travel along the slope longitudinally – i.e. up- and downhill – otherwise there is a risk of tipping. In addition, avoid changing direction and abrupt changes in speed or direction. Mowing a slope or embankment requires a smooth and even driving style.
Depending on the size of the slope, it may be useful to empty the collection box early, and more often than normally necessary. This ensures optimum weight distribution throughout and therefore optimum handling.
Let the robotic lawn mower mow the slope
If you need to mow a slope in your own garden, in many cases you can leave this to a robotic lawn mower without any worries. STIHL iMOW® robotic mowers, for example, can handle an gradient of up to 45%, which corresponds to around 24 degrees. Consult your robotic lawn mower’s owners manuals to find out in advance what gradients the model is designed for. If your robotic lawn mower is suitable for the relevant incline, you can relax and let the robotic lawn mower do its work.
Mowing steep slopes with a brushcutter
Using a lawn mower on steep banks and hills can be dangerous, so in these cases it’s best to use a brushcutter. With the right working technique, you can mow your lawn on a slope with impressive results. Work across the slope and start at the bottom.
If you mow a strip crosswise on the slope, the cuttings will fall on the lower side of the strip. So if your mowing tool turns anticlockwise, start at the bottom right of the slope and move to the left.
Then go back to the start of the cut strip and mow the strip above it. With this technique the clippings always fall on areas that have already been mown, meaning you can easily reach all the grass that needs to be cut.
This method is best suited for mowing steep slopes or maintaining the lawn on a difficult incline. Click to watch a tutorial video on how to mow on a slope with a brushcutter.
