Increasingly popular with UK gardeners, robotic lawn mowers are a welcome, hands-free alternative to traditional petrol and electric lawn mowers. Because a robotic lawn mower is fully automatic, it can be a brilliant option for gardeners who have mobility concerns, are away from home a lot, or simply find mowing a chore. Powered by rechargeable Lithium-ion batteries, most mowers are guided by a boundary cable laid around the edge of the lawn, which helps the robotic lawn mower identify where to mow and to avoid flower beds, trees and other obstacles.
While we tested models from a number of different brands, note that all of them offer a range of mowers with varying sizes, capabilities and features.
To compare these robotic models against other types of mowers, see our reviews of the best cordless lawn mowers, the best electric mowers and the best push mowers. And, if you're looking to give your lawn a bit of TLC, our experts have tested a range of manual and powered aerators and scarifiers - check out the best scarifiers and best aerators reviews. You can also keep edges looking neat with our tests of the best strimmers or pick of the best lawn edging.
Best robotic lawn mowers at a glance
To help you find a robotic lawn mower suitable for your garden, we tested a range of mowers for different size gardens, including gardens with slopes and a complex shape. Each mower is in use for weeks at a time to allow us to assess its battery capacity and cutting proficiency as well as ease of use.
Each mower in our review has a detailed list of pros and cons for clarity and has been rated according to set up and ease of use, cutting performance, extra features and value for money. Every robotic mower in our round-up below has scored a minimum of four out of five stars, so you can buy with confidence.
The robotic mower industry is constantly evolving, with new developments and advances, and we are currently testing a number of the latest models ready to update this review shortly. Please check back soon to see the results of our new review.
- Best robotic lawn mowers
- Best of the rest
- How does a robotic lawn mower work?
- What are the benefits of a robotic lawn mower?
- How to choose the best robotic lawn mower
- How to clean a robotic lawn mower
- How we tested robotic lawn mowers
Husqvarna Automower 405X
RRP: From £1899.00
Our rating: 4.5 out of 5
- Unobtrusive colour
- Easy connectivity
- Clever mowing features
- GPS theft tracking
- High price
- Short warranty
Awarded a BBC Gardeners’ World Magazine Best Buy for features, the Automower 405x boasts a huge range of features that help the mower cut well and make the experience easy for the user. These include, three different start points, switching mowing pattern according to where it’s mowing, such as through a narrow passage, frost guard and weather time that automatically adjusts the height according to the grass growth, and its new Rewilding Zone where you can leave 10% of the lawn aside to grow for pollinators.
It's available to buy as a bare mower, which is then installed by a dealer for an additional cost, or with the installation kit included and you install it yourself. Suitable for smaller gardens 600m2, the mower operates with both a boundary wire and a guide wire and unlike some other mowers, has a more flexible docking station, which doesn’t need a wide, clear space around it - ours was tucked neatly into the side of a hedge. It’s also easy to set up via the intuitive keypad or the impressive Automower Connect app, which allows you to change the schedule, adjust the height of cut, check on the mower's progress and receive notifications, simply and quickly no matter where you are. As an X model, the mower also has a built in SIM so you have both remote and voice controlled control. Our only confusion with set up was working out the scheduling needed, which took a couple of weeks to establish, and that the height of cut on the app is listed as 1-9, when it cuts between 20mm and 50mm.
The mower can cope with 40% slopes, which should suit most gardens. The slope in our test garden has a tendency to get muddy and slippery so at the installer’s advice, we used the spiked Terrain wheels which stop the wheels slipping. Only occasionally did the mower fail to get up the slope and when the weather was really wet we simply removed that zone from the work area. The mower cut consistently well and is very quiet, the only perceptible sound is the whirring of the blades as they cut. It occasionally missed spots on the lawn but overall this is a very easy to use and high performing mower.
The Automower 405x is just one in a large range of Husqvarna mowers to suit different size lawns. A host of accessories are also available, including a cover for the docking station and wheel brushes, as well as spare parts, from batteries and blades to wheels. Both the mower and the battery come with a 2 year warranty.
Our rating: 4.8 out of 5
- Light weight, simple to use and adjust
- Fast efficient cut
- ‘Park’ button on docking station
- ‘Intelligent’ performance and charging
- Long warranty
- No Smart connectivity
- Occasionally struggled on wet grass
This great value mower has an impressive finish. Nippy and quiet, the iMow has a single, steel rotary blade that's excellent for mulching and cuts efficiently and well, with a great finish, although it does get stuck occasionally on damp ground. The mower adjusts its speed itself according to the conditions, grass length and terrain and can tackle slopes up to 40 per cent.We awarded it a BBC Gardeners' World Magazine Best Buy for the best for medium lawns.
Read the full Stihl iMow 422P Robotic Mower review.
Buy the Stihl iMow 422 P from Just Lawnmowers
Although some models didn’t quite achieve a BBC Gardeners’ World Magazine Best Buy award, they still have great features that make them worth recommending. Browse our pick of the best of the rest robotic lawn mowers on test.
Honda Miimo 520
Our rating: 4 out of 5
- Easy to programme
- Quiet, smooth & efficient
- Tackles large/sloping lawns
- Long warranty (during 2019)
- Relatively few features
A large capacity model, this robotic mower is smooth, quiet and easy to use. Out of all mowers we tested, it can tackle the largest area and also copes well with sloping lawns up to 45 per cent. It’s smooth, quiet and unobtrusive. Its 360 degree sensors help it turn away when it comes near obstacles or pets and the blades automatically stop when it's picked up. Clumps of lush grass are dealt with by the spiral cutting option which mows round and round the grass until its cut. However it's the priciest option and has few features compared to other models.
Read the full Honda Miimo 520 review.
Buy the Honda Miimo 520 from Just Lawnmowers
How does a robotic lawn mower work?
Robotic lawn mowers are powered by rechargeable lithium ion battery and designed to cut the grass regularly, little and often so the lawn always looks neat. Clippings are mulched down back onto the grass, feeding the lawn and there are no grass piles to deal with or collection bags to empty.
Most robotic lawn mowers work by detecting the edge of perimeters via sensors or a boundary wire. The latter is laid out around the edge of the lawn — as well as any obstacles such as trees or island flower beds — to tell the lawn mower to stay within that area. When the mower senses the boundary wire, it will change direction to avoid leaving the lawn. Many have collision sensors so that if they bump into an object, the robotic lawn mower will automatically turn around and head off in another direction.
Some models mow randomly, eventually covering the entire lawn before returning to the docking station. Others use a more sophisticated GPS system that allows you to programme specific paths. Robotic mowers are programmed with a pin pad on the front of the mower but many models can also be controlled via an app, which allows you to monitor the mower's progress, schedule cutting times and let you know when servicing etc is required, easily and remotely. Once the mower has finished mowing, or if the battery is running low, the lawn mower will automatically return to its docking station, connect, and recharge.
These fully automatic mowers can save you hours of mowing time throughout the spring and summer, are great fun to watch and emission free. However, they are expensive, require an outside power source and careful installation, may not be appropriate for every style of garden and will not create stripes.
There are a number of benefits to buying a robotic lawn mower in comparison to the more traditional petrol or electric models.
These benefits include:
- Less work for you: Once installed and programmed, the robotic mower will automatically cut the grass according to your specific schedule. The lawn will always look tidy and the mower will return to its dock on its own when it needs recharging.
- Zero emissions: Unlike petrol mowers, they emit no emissions because they’re powered by a rechargeable Lithium-ion battery.
- Quiet:The lack of an engine also makes the mowers incredibly quiet.
Price and size ranges for robotic lawn mowers
Robotic lawn mowers are expensive, especially when compared to cordless or electric lawn mowers. Prices start around £600 with premium models for large gardens costing anything from £3000 up.
Most brands include a range of mowers to suit gardens of different sizes, from small 400m2 lawns up to large gardens and estates up to 5000m² in size and beyond.
Robotic lawn mower features
Beyond being fully automatic, the additional features on the best robot lawn mowers vary depending on model. They can include weather sensors, GPS navigation and smart connectivity, which is increasingly popular and useful for making the mower easier to programme wherever you are. Readily available as an app on your mobile phone, you can adjust the schedule and set up your phone without having to bend over the mower’s PIN board but you can also check on your robotic lawn mower while you’re away, track it if it’s stolen and see when it needs servicing.
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Good security is essential when paying for a machine in this price range and all mower have security features as standard. Some simply require a PIN code to start the mower, while others have lift sensors, alarms and a GPS tracker.
The latest innovation in the robotic mower world is the arrival of of a number of mowers that cut without the need for a boundary wire. Although some mowers could already do this they were primarily for very large open lawns or small gardens with particular types of boundary such as paving or raised beds. Now there are mowers that can identify exactly where they are, with the help of pin-point positioning via GPS or, are able to identify grass as well as other obstacles to work out where to mow.
We are currently testing some of these new mowers, so keep checking this page for updates and our latest reviews.
Robotic lawn mower requirements
Although they're fully automatic, once set up robotic lawn mowers are more complex initially compared to a traditional, petrol, electric and cordless mower.
A robotic lawn mower requires an outside power source to connect the docking station to and this ideally needs to be positioned out of direct sun and level. Most also need a clear area around them — typically two metres to the front and a metre each side, which can limit where you place the docking station, especially in a small garden.
Accessing the layout is also essential before purchasing a robotic lawn mower. Some models can struggle with narrow passages, uneven ground and steep slopes.
Finally, they need installing and the boundary wire and sometimes a guide wire too, laid. You can either do this yourself, which takes time or get a dealer to do it for you, which is usually an additional cost, although some models include installation by a dealer in the price. They will assess your lawn, lay your boundary wire for you and show you how to programme and operate the keypad. If you're installing the mower yourself, take care to follow the instructions precisely for the robotic lawn mower to run correctly.
Despite being fully automated, a robotic lawn mower should still be checked, cleaned and serviced regularly.
- To clean, make sure the machine is switched off and turn it over to check the blades for damage. Clean the chassis and blades with a brush, or a garden hose if dirt is more stubborn.
- Grass may need removing from the wheels and give the body a wipe down with a damp cloth.
- Blades should be able to pivot freely and damaged blades should be replaced. All blades should be replaced at the same time to ensure a balanced cut.
- A service each year is encouraged so that dealers can update software. They will also clean and replace any worn parts, including batteries.
How we tested robotic lawn mowers
The BBC Gardeners' World Magazine reviews team tested a range robotic lawn mowers for several weeks in different gardens. Some were installed for us by dealers while we installed the smaller mowers ourselves. They were programmed and left to work and were assessed according to the following criteria, with equal marks attributed to each:
- Set up and ease of use: Looked at installation and programming, including the need for a guide wire as well as a boundary wire, smart connectivity capacity and how easy it is to connect to the app.
- Cutting performance: Assessed how well it cuts the grass- the efficiency of cut and the neatness of the finish, its ability to evenly spread the cuttings and its ability to handle rough and damp grass. Also looked at run time and charge time and noise.
- Features: Focused on how well the mower could cope with obstacles or handle slopes, the number of zones you can programme it to mow, rain or temperature sensors, security features etc
- Value for money: Considered all of the above along with length of warranty and price, including installation cost where applicable.
For more information on our testing process, see How we review.
This review was last updated in June 2023. We apologise if anything has changed in price or availability.