Relatively new to the UK market, robotic lawn mowers are becoming increasingly popular as a 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, the mowers are guided by a boundary cable, which needs to be laid around the edge of the lawn. This helps the robotic lawn mower identify where to mow and to avoid flower beds, trees and other obstacles.
In this article, we review the best robotic lawn mowers and clearly outline the pros and cons of each one. We’ve considered value for money, battery life, cutting lengths and ease of use before rating them out of five according to their performance.
We suggest using this rating as a guide, while bearing in mind the size, shape and undulation of your lawn.
- 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
- Best robotic lawn mowers to buy
- How we tested
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 — along with any obstacles — to tell the lawn mower to stay within that area.
When it 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 turn around and head off in another direction.
Most 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 some 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.
Once it’s finished mowing, or if the battery is running low, the lawn mower will automatically return to its docking station, connect, and recharge.
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 cuts the grass little and often. The lawn always looks tidy, clippings are dropped into the grass for nourishment and the lawn mower returns 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 at £500 and more premium models can cost upwards of £2000.
A range of sizes are also available. The smallest models are best suited to small or medium-size gardens, while the bigger and more powerful models can mow lawns up to 5000m² in size.
Warranty on a robotic lawn mower is typically between two and five years.
Robotic lawn mower features
Beyond being fully automatic, the additional features on the best robot lawn mowers vary depending on the model. However, these features can include weather sensors, GPS navigation and smart connectivity.
The latter can make the mower easier to programme because it allows you to use a mobile device, such as a phone or tablet, to set it up rather than bending over the machine’s PIN board.
Smart connectivity also allows you to check on your robotic lawn mower while you’re away and track it if it’s stolen.
Good security is essential when paying for a machine in this price range. Some simply require a PIN code to start the mower, while others have lift sensors, alarms and a GPS tracker.
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.
Firstly, a robotic lawn mower requires an outside power source to connect the docking station to. The mower will then dock and recharge when necessary.
There are requirements when it comes to the docking station itself, too. Ideally it should be 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.
This can limit where you can 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 laid. Robot lawn mowers may be expensive but many 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.
Cheaper mowers can be installed without any professional guidance but the instructions must be followed precisely for the robotic lawn mower to run correctly.
Despite being fully automated, a robotic lawn mower should still be checked and cleaned 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.
Through rigorous testing, we’ve found 8 of the best robotic lawn mowers to help keep your lawn in trim.
All of the models within this list received a rating of 3.8 out of 5 stars (or above) so you can be certain of their high quality and performance.
- Best Buy: Worx Landroid S300 WR130E Robotic Mower
- Best Buy: Stihl iMow 422P Robotic Mower
- Best Buy: Husqvarna Automower 315X Robotic Mower
- Cub Cadet XR2 Enduro Series 1000 Robotic Mower
- Gardena Smart Sileno Life Robotic Mower
- Flymo 1200R Robotic Mower
- Honda Miimo 520 Robotic Mower
- John Deere Tango E5 Series II Robotic Mower
Best robotic lawn mowers to buy in 2021
Browse our choice of the eight best robotic lawn mowers, below.
Worx Landroid S300 WR130E robotic mower review
Our rating: 4.5 out of 5
- Quiet and light
- Correct set-up indicator lights
- Easy to programme, via keypad
- Smart connectivity App
- 90 minute run time
- Three year warranty
- Intelligent programming to continuously map your lawn
- Battery interchangeable with the Worx PowerShare range of tools
- Add-on accessories takes it out of the budget range
- It doesn’t cut to the edge of the lawn
- Do-it-yourself boundary set up
The cheapest robotic mower we’ve tested, the Worx Landroid S300 WR130E is straightforward to use and comes with a useful – but limited – range of features. Compact and quiet, it features three small pivoting blades on the cutting disc, which give it a cutting width of 18cm. It has intelligent programming, which means it works continuously to map your lawn, pausing to recharge and then carrying on from where it left off. It cuts in a zig-zag pattern, rather than straight lines, so the lawn looks neat and stripe-free, and it’s able to navigate through narrow passages, (not all the models we tested can do this), and cope with slopes of up to 35%. It also turns efficiently, rather than constantly reversing, which results in a quicker cut and protects the lawn from too much wear-and-tear, another feature that not all the mowers we tested have.
Read the full review: Worx Landroid S300 WR130E Robotic Mower review
Stihl iMow 422P Robotic Mower
Our rating: 4.8 out of 5
- Buy now from Robot Lawnmowers (£1,199)
- 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 tackling slopes up to 40 per cent.
Read the full review: Stihl iMow 422P Robotic Mower review
Husqvarna Automower 315X
Our rating: 4.8 out of 5
- Buy now from My Robot Center (£1429)
- Straightforward to programme & adjust
- Smooth, efficient & quiet
- GPS navigation & guide wire system
- Connectivity/voice control
- High level of security
- Maximum area smaller than others for price
The Automower is quiet and unobtrusive and its three free-hanging blades cut well. It comes with a GPS Smart mowing system which maps the lawn before mowing and keeps track of where it has cut, so it copes well with complicated lawn shapes and narrow passages. It can also tackle slopes up to 40 per cent. It cuts around raised beds by ‘bumping off’ them but edges were not as neat as others in these areas.
Read the full review: Husqvarna Automower 315X review
Cub Cadet XR2 Enduro Series 1000 Robotic Mower
Our rating: 4.3 out of 5
- Buy now at Diamond Mowers (£1,149)
- Cuts over edges
- Wide cutting width
- Good features for price
- Connectivity and voice control
- Keypad hard to use
- Comparatively noisy
- Shorter run time
This robotic mower is good value. A turbo mode helps it tackle longer grass and the floating mowing deck helps it cope with slopes up to 36 per cent. It’s particularly good at cutting edges. However, it sometimes fails to park, and was by far the noisiest mower tested.
Read the full review: Cub Cadet XR2 Enduro Series 1000 Robotic Mower review
Gardena Smart Sileno Life robotic mower
Our rating: 4.3 out of 5
- Buy now from Amazon (£1,095)
- Quiet and light
- Narrowest cutting width is 60cm
- Comparatively wide cutting width
- Connectivity and Sensor control function
- Instructions and keypad could be clearer
- Both guide and boundary wires to set up
- Larger edges left than others
This mower cuts quietly, smoothly and efficiently, leaving a clean finish but it does leave wider edges than other mowers. It can cope with slopes of up to 30 per cent and fits through narrow passageways of just 60cm, which is a bonus.
Read the full review: Gardena Smart Sileno Life robotic mower review
Flymo 1200R robotic mower
Our rating: 4.3 out of 5
- Buy now from B&Q (£190)
- Easiest to set up and program with clear instructions
- Cuts close to edges
- Comparatively long run time
- Excellent value and cheapest mower tested
- Comparatively large and bright
- Requires largest area around docking station
- Needs 90cm between boundary wire
- Both guide and boundary wires need to be self-installed
A simple, low-priced efficient mower, great for trying out robotics in gardens no bigger than 400m². Easily the cheapest mower tested and for a simple efficient entry level mower with a two year warranty we think the 1200R is excellent value for money. It also comes with spare blades. It can cut in two separate areas although you do have to physically pick the mower up and carry it into the second area and then mow it on the manual setting. Alternatively, you can buy a second docking station. The 1200R has no smart connectivity. Security features include PIN code operation, a lift sensor and alarm.
Read the full review: Flymo 1200R robotic mower review
Honda Miimo 520
Our rating: 4 out of 5
- Buy now from Just Lawnmowers (£2,079)
- Easy to programme
- Quiet, smooth & efficient
- Tackles large/sloping lawns
- Long warranty (during 2019)
- Highest price
- 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 review: Honda Miimo 520 review
John Deere Tango E5 Series II Robotic Mower
Our rating: 3.8 out of 5
- Buy now from Balmers GM (£1,599)
- Wide and high cut
- Very simple to use keypad
- Excellent for large lawns
- Long run time
- Not suitable for narrow areas
- Awkward height adjustment
- PIN code is only security feature
- No Smart connectivity
This substantial and robust mower is great for cutting large lawns but it can’t cope with narrow gaps. Large back wheels help it tackle slopes up to 36 per cent and its single steel blade cuts evenly and closely with a good finish. It’s a bit noisier than other models we tested and has few features for the price.
Read the full review: John Deere Tango E5 Series II Robotic Mower review
When testing these robot lawn mowers, our experts consider a range of variables including price, size, cutting lengths, battery life, and security, along with how easy the models are to install and programme.
Once installed, our experts assessed the lawn mowers depending on how well they maneuvered around obstacles, dealt with slopes and if any corners or areas of the lawn were missed.
When the test is complete, each machine is rated out of five stars and the robotic lawn mowers that really impress our experts are awarded Best Buy status. Each review is broken down into concise pros and cons lists to help you decide which lawn mower is best for your garden.