Best robot lawn mower 2021: robotic mowers to cut the grass as you chill

Top autonomous cutting machines to spruce up your lawn while you loaf about in the summer sun

Best robot lawn mowers 2021
(Image credit: Honda)

The best robot lawn mower could be THE perfect garden tech for 2021. This summer more than any before everyone is going to be out and enjoying themselves after months of being stuck in the house, and a robot lawn mower can make garden work easy while you're relaxing and soaking up the sun.

Mowing the lawn can be an arduous task. Luckily, modern tech companies have noticed the problems that mowing a garden can present and have come up with a nifty solution: the robotic lawn mower. Unlike the best lawn mowers and best petrol lawn mowers, these turf cutting systems require little to no human input at all, and can be left to routinely slice that sward.

Here at T3 we love the idea of getting stuck in to food cooked on one of the best barbecues or best pizza ovens, all the while watching as a robot lawn mower maintains your lawn, safe in the knowledge that by the time the sun goes down and you're sitting out under some of the best outdoor lights on the market, you've got an immaculate garden.

And the robot lawn mowers below can make that dream into a reality.

The best robot lawn mowers you can buy today

best robotic lawn mower 2021: Robomow RC 308uT3 Award

(Image credit: Robomow)

1. Robomow RC 308u

Best robot lawn mower for small to medium gardens

Mowing width: 28cm
Mowing height: 16-60mm
Maximum lawn area: 1,500m sq
Slopes: 36%
Battery type: 26v lithium
Charge time: 70-90 mins
Average runtime: 70 mins
Noise level: 69db
Dimensions: 63x46x21cm
Weight: 11.4kgs
Reasons to buy
+Excellent performance+Up to 36% slopes

In the arena of autonomous lawn mowers, the Robomow RC 308u is a winner. Granted, setting it up requires a lot of time spent either pinning the special perimeter wire onto the grass or burying it in a long mini trench. But once that frankly annoying task is out the way, you can sit back and relax while the little fella trundles haphazardly all over the lawn  

The Robomow will zig-zag across the lawn cutting everything in its path for about 70 minutes at a time before returning to the charging base for a 70-90 minute top up. Then it’ll set off again for another series of sessions until your lawn looks like an Augusta putting green.

This particular model has a small cutting deck of 28cm so it’s good for lawns up to a maximum of 1,500 square metres and with slopes not exceeding 20˚ or 36%. You can even command this robot mower with an app so you never have to leave the deckchair. Add a relatively low noise level and you have an ideal purchase for lazy gardeners.

Best robotic lawn mower 2021: Bosch Indego M+700

(Image credit: Bosch)

2. Bosch Indego M+700

The best robot lawn mower for small lawns

Mowing width: 19cm
Mowing height: 30-50mm
Maximum lawn area: 700m sq
Slopes: 27%
Battery type: 18v lithium
Charge time: 60 mins
Average runtime: 75 mins
Noise level: Not stated
Dimensions: Not stated
Weight: 7.1kgs
Reasons to buy
+Intelligent navigation+Bosch reliability+Spot mowing
Reasons to avoid
-Only for small lawns

This brand new brushless motor model from the house of Bosch is another ideal option for small urban lawns. Once set up, its intelligent LogiCut navigation system calculates the most efficient mowing pattern before setting off on its first cut. Unlike many robotic mowers that adopt a zigzag pattern, this one is said to cut lawns using a diagonal up-and-down method. This means that the patterns on your lawn during the first few cuts won’t look quite so irregular. SpotMo is another cool feature that enables the Indego to mow small patches of growth under tables and other garden furniture (obviously you’ll need to move the furniture to the side first).

As is the case with many robotic lawn mowers, this one monitors weather forecasts and only ventures out when it’s mostly dry – a good thing because wet grass rarely cuts well. It can also be controlled via the Bosch Smart Garden app and Amazon Alexa.

The Indego M+700 has one of the smallest cutting decks here (just 19cm) so make sure your lawn isn’t larger than the stated 700 square metres. That said, if your patch does meet the correct dimensions and it doesn’t have inclines steeper than 27%, then the Indego is definitely worth a punt. It’s a Bosch, after all.

Best robotic lawn mower 2020: Flymo Robotic Lawnmower 1200 R

(Image credit: Flymo)

3. Flymo Robotic Lawnmower 1200 R

The best affordable robot lawn mower

Mowing width: 17cm
Mowing height: 20-50mm
Maximum lawn area: 400m sq
Slopes: 25%
Battery type: 18v lithium
Charge time: 50 mins
Average runtime: 65 mins
Noise level: 45-58db
Dimensions: 58x46x26cm
Weight: 7.4kg
Reasons to buy
+Attractive price point+Nice and quiet at 58 db(A)
Reasons to avoid
-Other models have more features

Flymo, the well-known garden appliance brand, has excelled itself with the 1200 R. The mower, which now costs just £549, is best for people who want a clean cut with no tyre marks or grass left around.

According to the company, the 1200 R has a blade that is specifically designed to reduce mess which, when coupled to the excellent range – 400 square meters – makes for a very useful machine that just gets the job done.

The mower is exceptionally quiet, at just 58dB, which is roughly the same volume as a spoken conversation. Great value.

Best robotic lawn mower 2020: McCulloch ROB R1000

4. McCulloch ROB R1000

The best mid-priced robot lawn mower

Mowing width: 17cm
Mowing height: 20-50mm
Maximum lawn area: 1,000m sq
Slopes: 25%
Battery type: lithium
Charge time: 50 mins
Noise level: 57-59db
Dimensions: 58.6x43.7x25.7cm
Weight: 7kg
Reasons to buy
+Ideal for small or medium sized lawns+Programmable controls+Anti-theft protection
Reasons to avoid
-Limited features-Only operates within a single zone

Ideal for small to medium size lawns of up to 1,000 square metres, the McCulloch ROB 1000 is an ideal entry point into the robot lawnmower world. It’s not particularly flashy or feature-packed, but it performs all the usual robot lawnmower duties – automatically mowing the lawn within its boundary wire, according to the times and dates you've programmed into it, and returning to its docking station to recharge when its battery gets low.

It also includes an audible alarm and PIN protection to help protect it against theft. And it can handle inclines of up to 25% – handy for sloping gardens.

The McCulloch ROB R1000's biggest catch? It can only mow within a single zone (that is a front or back lawn). Many of its rivals can handle multiple zones, enabling the whole garden to be mowed.

McCulloch ROB R600 review: can this robotic lawnmower tame T3's garden?

Best robotic lawn mower 2021: Gardena Sileno City 250

5. Gardena Sileno City 250

A good, mid-priced robot mower for small gardens

Mowing width: 16cm
Maximum lawn area: 250m sq
Slopes: 25%
Battery type: lithium
Charge time: 60 mins
Average runtime: 65 mins
Noise level: 58db
Dimensions: 55x38x23cm
Weight: 7.3kg
Reasons to buy
+Built for urban lawns+Long run time+Reasonably priced
Reasons to avoid
-Prefers flatter terrain-Narrow cutting width

If you’re a busy city-dwelling bod with a small garden up to 250 metres square, this relatively affordable 16cm ‘city’ model could just be the answer to your overgrowing sward conundrum.

The Sileno City’s Lithium battery provides a continuous cutting time of 65 minutes before the mower heads back to its base station for a nifty 60-minute top-up. It’s quiet, too, and water resistant against both heavy rain and blasts with a hosepipe.

As is the case with most robot mowers, you’re advised to remove any raised garden borders or the mower will stop an inch or two from the flowerbed, leaving an unsightly strip of overgrown grass, to which you’ll then have to take a strimmer. And, as any gardener will tell you, strimming is arguably the biggest pain of all garden duties, leaf clearance notwithstanding (see our separate feature on garden blowers). Also, make sure your garden isn’t too hilly because this mower’s maximum inclination is a not especially impressive 25%.

The Sileno City cuts very well, albeit slowly, and is very adept at negotiating tight turns in confined areas. The bubble-type keypad interface is relatively easy to use too (it comes with its own onboard programming assistant), but those with poorer eyesight might have trouble reading the LCD screen in bright sunlight.

Of course, there is a good argument against having an expensive robot mower that cuts such a small area – after all, it wouldn’t be that much of an inconvenience to get off one’s arse and have a quick 10-minute whizz with a cheap cordless or electric model. But that’s your prerogative.

best robot lawn mowers 2021 Gardena Smart Sileno+

(Image credit: Gardena)

6. Gardena Smart Sileno+

An intelligent robot mower with smartphone control

Mowing width: 22cm
Mowing height: 20-60mm
Maximum lawn area: 1,600m sq
Slopes: 35%
Battery type: 18v lithium
Charge time: 50 mins
Average runtime: 65 mins
Noise level: 56-60db
Dimensions: 63x51x25cm
Weight: 8.5kg
Reasons to buy
+Ideal for larger, more complex lawns+Smartphone monitoring and control+Intelligent operation
Reasons to avoid
-Nothing really

The Smart Sileno+ is part of Gardena’s smart system range, which includes things like electronic timers and automatic garden sprinklers. That’s handy because the devices not only talk to each other when connected to a gateway via your home router, they also have internet access as well – and that means you can control them remotely using the free Gardena smart system app for iOS and Android. Clever. 

In practice this means that the Gardena Smart Sileno+ robot mower knows only to mow the garden when the garden sprinkler isn’t working. It also includes Gardena’s SensorCut System, which effectively measures the height of the grass so it only cuts your lawn when necessary. Anything else? Unlike less capable mowers, Gardena Smart Sileno+ can handle complex, sloping lawns (with inclines of up to 35%) and can navigate even narrow areas with ease. 

Best robotic lawn mower 2021: Honda Miimo 40 Live

(Image credit: Honda)

7. Honda Miimo 40 Live

The best compact robot lawn mower

Mowing width: 19cm
Maximum lawn area: 400m sq
Slopes: 27%
Battery type: 18v lithium
Charge time: 45 mins
Average runtime: 45 mins
Noise level: 63db
Dimensions: 44x36x20cm
Weight: 8kgs
Reasons to buy
+Very reliable+Fast recharging+Ideal for small urban lawns

•Buy the Honda Miimo 40 Live direct from Honda

There’s a good argument for getting a Honda robotic mower. After all, the company has been at the forefront of the burgeoning garden robotics industry for many years and we all know about Honda’s excellent reliability record in all matters mechanical. If its humanoid robot Asimo can walk, dance, kick a football, interact and carry things, it’s probably safe to say the company’s new Miimo 40 will cut a lawn reliably and with very little fuss.

The Miimo 40 is designed for small urban gardens up to 400m2 and has a cutting width of 19cm and an 18v lithium battery that provides up to 45 minutes of cutting time per 45-minute charge. Some of its features include the ability to handle inclines of up to 27%, monitor the weather via MeteoGroup before heading out on a cutting session, and even be controlled using the Mii-Monitor 40 app and Amazon’s Alexa.

As with all robotic mowers, it’ll take about a week or so before you’ll see the fruits of its labours but, before long, your lawn will look spick and span without you so much as having lifted a finger. For best results – and fewer back problems – get Honda’s installation team to set it all up for you. Top dollar cutting from a highly reliable brand.

Best robotic lawn mower 2021: John Deere Tango E5 Series II

8. John Deere Tango E5 Series II

A very solid, if pricey, robot mower for larger lawns

Mowing width: 30cm
Mowing height: 19-102mm
Maximum lawn area: 2,200m sq
Slopes: 36%
Battery type: 25v lithium
Charge time: 80 mins
Average runtime: 90 mins
Noise level: 51.2-62.2db
Dimensions: 77.5x53.5x36cm
Weight: 15kg
Reasons to buy
+Best-in-class blades+2,200 square metre range
Reasons to avoid
-Nearly two grand

John Deere makes some of the most reliable utility equipment around – and the Tango E5 Series II is no exception. It works in any weather condition across almost any terrain and does so quickly and quietly. Oh, and it has a range of up to 2,250 square meters.

Of course, lots of other mowers do that, too, but the Tango E5 is famous for its star-shaped blade design and quality, which John Deere is proud to talk about. Obstacles, like rocks, are protected against, which reduces the need to replace the blades or make repairs to the mower. The focus on blades may seem trivial, but it's something that makes the Tango E5 one of the best robotic lawn mowers around.

How to choose the best robot lawnmower for you

Getting every piece of grass an even length, making sure that every area is covered, and so on can be annoying, and that's not to mention inclement weather conditions.

As the name suggests, robotic lawn mowers are just that. They happily move around a garden, cutting grass to an equal length and navigating most tricky terrain while you kick back and relax.

Depending on your garden type, different mowers can work better than others – for example, if you have a MASSIVE garden you'll want a large lawnmower with plenty of battery life, and if you have a small-but-hilly garden you'll need a mower with plenty of power and grippy wheels. 

Blade width is important, as are other features, such as the ability to remote control the mower with your smartphone.

However, you can't just buy a robotic mower, unbox it, stick it on the lawn and expect it to start cutting immediately because it needs a perimeter wire inserted around the entire lawn (preferably under it) and any obstacles like trees, benches and arbours. The perimeter wire is a vital component that tells the mower when it's reached the edge so it doesn't run riot through the roses or tumble into a void. Instead, it'll turn around and mow somewhere else. 

Another thing worth noting is that robotic mowers tend to travel in a haphazard fashion that may make you wonder if you've bought a duffer. You haven't, it knows exactly where it's been and where it's going. So, bear with the zigzag patterns on your lawn for the first day or two and eventually the whole sward will look evenly mowed and as smooth as a billiard table.