Robotic mowers for slopes - buying tips

Slopes and inclines pose a special challenge for robotic mowers. We have buying tips for a suitable robotic mower.

Sloping gardens are visually appealing and offer a variety of unusual design options. At the same time, the amount of work involved in some activities becomes considerably more difficult. Mowing a lawn with a slope is physically more challenging. For this reason, it's smart to just let the robotic mower do the work, which has been designed for slopes.


In contrast to a flat garden, a lawn mower cannot simply be pushed across the surface of a slope. In turn, the device requires considerably more power, especially if the blades have to work on uneven ground. This wear and tear can cause the blades to break. Sooner or later, the motor and service life of the device may suffer from high stress if the robotic mower is not designed for such use.


In order to know how big the slope of a garden actually is, you should first calculate it before making your purchase. This works quite well with two yardsticks. Unfold one stick to a length of 1 and lay it on the slope. Hold the stick from the top of the slope and raise it until it is horizontal. Then measure the distance from the horizontal point of the stick to the flat ground using a second yardstick.

If you measure 35 cm, for example, this corresponds to a slope of 35%. This value must then be converted into the slope angle. This is not done proportionally but is somewhat more complex. Relevant for lawn mowers and robots are the following conversions:

10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 100%

5,7° 8,5° 11,3° 14,0° 16,7° 19,3° 21,8° 24,2° 26,6° 28,8° 31,0° 45,0°

Of course, you can be more precise with additional spirit levels, lasers and tape measures.

Caution is required when laying the perimeter wire. The specified maximum slope may often amount to half of the cable (follow manufacturer's instructions).


Robotic mowers are actually the ideal solution for mowing on slopes. A gasoline mower, which can require a considerable amount of effort on a slope even with an automatic drive, is accompanied by the risk of accidents. However, A robotic mower does the work autonomously and reduce  the risk of injury.

The devices usually manage slopes of up to 35°-45°. There are manufacturer specifications that provide information about how a special drive is also suitable for the slope. Laying the perimeter wire or using models with sensors is done along the edge of the lawn as with any other device.

Another distinctive feature of the devices is the wheel position. The drive wheels are usually larger, allowing for better power transmission and help increase grip on the ground. Some suppliers offer additional spikes or traction wheels whose tread can provide optimal grip even on wet grass.


In order for robotic mowers to perform well on slopes, the first thing that matters is the slope capability. Naturally, this should not be less than the slope of your own garden. Once this has been determined, other criteria play a role in ensuring that the robotic lawnmower can achieve excellent cutting results.

Traction wheels help provide  optimum grip

For one thing, robotic mowers for slopes usually have not only three wheels, but also particularly good traction with a fourth. The size of the wheels also determines the tilt resistance of the device, so this is usually somewhat more pronounced with robotic mowers for slopes. A course tire can also provide the necessary grip in wet conditions and helps prevent the robotic lawnmower from slipping on slopes. If these are not included in the scope of delivery, special tires or spikes are often available as optional accessories that expand the functionality of the robotic lawnmower.

The necessary power on slopes

Mowing a slope requires more power. The motor requires more capacity and is accordingly often louder than a model that is only designed for level lawns. Therefore, when buying, pay attention to the specification of the volume in dB. If you have sensitive neighbors, a robotic mower with up to 60 dB is definitely recommended.

However, the higher force requirement leads to a lower area output since the robotic lawnmower will have to return to its charging station more often.

Those who buy a robotic lawnmower and have some slopes in their garden would do well to plan a buffer between the lawn area and the recommended area output. The battery power of the robotic lawnmower should also be as large as possible and have a strong charging capacity.

Robotic mowers with all-wheel drive

Analogous to vehicles, there are also robotic mowers with four-wheel drive, although most models are equipped with rear-wheel drive. These also cope well  with large inclines. Unfortunately, they are not always suitable if the robotic lawnmower has to make a turn at a steep spot. In this case, a front-wheel drive model is more recommended and is characterized by greater maneuverability. Many robotic mowers require a run-out zone with a maximum slope of 15% to be able to turn without any difficulty.

Inclination sensors

Some robotic mowers are equipped with special sensors that measure the respective slope. If a slope becomes too steep, the device is designed tol turn before continuing up the slope.

Conversely, the device should also have good braking capabilities to quickly reduce speed at the end of a downhill slope. That’s where software that reacts intelligently to slopes is helpful.

The cost of the robotic mower

Since robotic mowers for slopes require a more powerful motor on average, the price may also be slightly higher compared to models for flat surfaces. In return, you can be sure that the device is designed to  cope with the slopes  and cut the lawn here just as accurately and cleanly as on level ground.

Further buying criteria for robotic mowers

As with robotic mowers on level terrain, other criteria should play a role in the decision of your purchase.

  • Different cutting levels help to e maximize flexibility on ornamental and sports lawns or growth phases and dry summer months.
  • Some robotic mowers are particularly easy to control and program via an app. When equipped with a GSM module, this is even possible when you’re on vacation.,


Those who cannot or do not want to buy a robotic mower, still have some alternatives.

  • A hand mower is lighter than powered lawn mowers, which sometimes makes the job easier.
  • Power scythes are less suitable for ornamental lawns with low cutting heights, but are otherwise handier than a classic lawn mower.
  • For gasoline mowers, the valves of the engine should be on top (OHV), so that they (and  the pistons) can be lubricated from above to minimize leaking oil while operating on steep slopes. On slopes of more than about 10-15°, 2-stroke engines have an advantage over the 4-stroke engines.

Lawn tractors are also an excellent solution for slopes up to 15-20°. These machines are designed to have enough power to mow even on slopes. Unlike a lawn mower, you must always be careful not to mow across the slope to avoid the risk of accidents. However, its operation generally remains limited to large and very large gardens.

Reshaping the slope

If regular mowing is too much of a hassle, you could also redesign your yard. Even without a lawn, attractive slopes can be created with stone walls, stairs and beds, making a lawn mower completely unecessary. This requires a little work at first but saves a lot of time later in the long run.

A meadow is also ideal for slopes. Not only is it bee-friendly, but it also reduces the amount of mowing required. In contrast to lawns, meadows generally only need to be cut twice a year. Power scythes or bar mowers are more suitable.


Especially on slopes, current ground conditions play an important role for the traction of the robotic mower. Moisture often causes the wheels to spin more easily or the robotic lawnmower could slip. The steeper the slope, the more important it is to choose suitable weather to allow the lawnmower to work optimally.

Leaves can also reduce the grip on the ground. It is, therefore, advisable to remove leaves from your lawn regularly, especially in autumn.

Robotic mowers are an ideal solution for mowing slopes precisely and evenly In contrast to push models, much less force is required to operate them. Compared to cordless mowers, gasoline mowers and lawn tractors, robotic mowers are designed to  easily cope with steep slopes of up to 45° without reducing their service life. However, when buying one, you should definitely make sure that the model fits the slope, as not all robotic mowers are equally suitable.

  • Not every robotic lawnmower is equally rainproof. Thus, pay attention to the protection class of each device regardless of weather conditions when purchasing.
  • Manufacturers specify the maximum area output based on the assumption that the robotic lawnmower will be in use between 12 and 24 hours a day (the calculation basis differs from manufacturer to manufacturer). If you want it to take breaks, it is advisable either to calculate the required area output for the desired operating times or plan a sufficient buffer. This is particularly important on slopes, as these can significantly reduce the area output.

Other advantages of robotic mowers

Robotic mowers are extremely practical on slopes. The clever garden helpers mow the lawn fully automatically and reduce the effort required for fertilizing by mulching. With freely selectable mowing times, the lawn is always  manicured and well cared for.

Meanwhile, the devices are designed to operate much more quietly than electric or gasoline-powered lawn mowers,. Your neighbors will also appreciate the low noise level.

All that is required to get started, is the  installation of a perimeter wire (unless the device has a grass sensor). While in operation, robotic lawnmowers are recognized  by, useful control functions via app and low maintenance .