Product test
The Yuka Mini robot lawnmower is practically the golden child of gardening
by Martin Jungfer
Gardena’s new robot lawnmower drove me to the brink of insanity
10/6/2025
Translation: Katherine Martin
Pictures: Martin Jungfer
It’s been a long time coming, but Gardena now sells a robot lawnmower that works without a perimeter wire. Alas, I ended up banishing it from my garden after an eight-week test.
By releasing the Sileno Free, Gardena’s hoping to catch up with its rivals. While other brands have been selling perimeter wire-free mowers for years, Gardena’s been slow to do so. The Sileno Free only hit the shelves this spring. So, is it worth the wait?
Let me start with a word of warning. This review is in-depth, so it’s longer than my other articles. If you just want to know what rating I’m giving the Sileno Free, you can skip straight to the «In a nutshell» section to find out why I awarded it two stars.
The concept sounds pretty good on paper. You don’t need to lay any cables to use the Sileno Free, let alone set up any small antennas or transmission masts. Satellite signals and AI-based technology called LONA Intelligence supposedly allow Gardena’s new robot lawnmower to keep up to 600 square metres of lawn in good condition.
Improved aesthetic
I’m a satisfied user of the 2020 Sileno City, a robot lawnmower that does what it’s supposed to. The effort I initially had to put into installing its perimeter wire has long since paid off. But my trusty old mower gets to take a break when Gardena provides me with its new Sileno model to review.
The Sileno Free has been given a design upgrade. It boasts more curves than its predecessor as well as a few practical improvements, including a handle on the top. This is handy for carrying the mower back to its charging station if it veers off course or if you need to move it to another patch of grass.
The control panel’s now positioned right on the top instead of under a cover, so you always have quick access. There’s now a button for communication between the mower, the Gardena Gateway and the satellites.
When I flip the Sileno Free over, I discover the most exciting feature for a user like me. There are now two cutting discs, each with three freely rotating blades. Gardena’s marketing people call it a «DualCutting Disc» – the missing space is intentional.
Gardena’s new robotic lawnmower chassis is what folks in the car industry would call «new platform». Regardless of what type of lawn a Sileno Free model is designed for, it’ll be built on this new platform. As is the case with previous mowers, an electric motor transmits power to two large wheels. However, there are now two small wheels at the front instead of one, making the mower more manoeuvrable.
Since the extra cutting disc and GPS module need additional space, the Sileno Free is 63 cm long, 43 cm wide and 26 cm high. This means it has 40 per cent more volume than my old Sileno City.
Connection and set-up
The new Gardena mower doesn’t fit into my old charging station. The charging connection has been redesigned, with the contact points now better protected against moisture and less susceptible to corrosion as a result. Mind you, I’ve never had these issues with the old model.
Cracking on, I connect the low-voltage cable to the Sileno Free charging station. This is basically a big chunk of plastic you can anchor to the ground with five plastic screws. There are cables attached to the bottom to help the lawnmower dock. A garage isn’t included, but you can buy one separately as an accessory.
The hardware installation is completed by a black box known as the smart Gateway. You need a power supply and either a LAN or Wi-Fi connection to use the device. The Gateway isn’t waterproof, so you should keep it in a dry garage or indoors. Its transmission is strong enough to get a signal through an outside wall, towards the garden.
First venture onto the grass pushes me to the limit
I ended up spending a good hour guiding the Sileno Free around its future mowing ground via remote control. Another issue contributing to this drawn-out process was the fact that I couldn’t complete and save the perimeter run after just one lap, as I couldn’t get a GPS signal. My only option was to cancel the run and start from scratch. It was a maddening experience that pushed me to the limit. As it turns out, it wouldn’t be the last.
Maiden voyage in the Jungfer garden
Once it’s latched onto the satellite signal, the robot lawnmower cruises through my L-shaped garden. My lawn’s bordered by walls, edging stones, a hedge and the panes of a windowed seating area. A tree and a parasol serve as additional obstacles.
There’s only about 100 square metres of lawn. It takes the mower about an hour to give it a once-over. My old Sileno City mower doesn’t finish the job quite as quickly as the Sileno Free. However, the little bit of time you gain back doesn’t have any impact on your day-to-day life.
Problems with software and satellite
Even moving the charging station doesn’t help matters. At one point, the robot mower thinks the charging station is positioned two metres away from where it actually is. It keeps heading for a spot at the edge of the lawn before eventually giving up and sending me an app notification informing me that it can’t reach the charging station due to a «blockage». Cursing to myself, I think, Bro, the «blockage» is you!
Generally speaking, Gardena’s reliance on satellite reception is a downer. Cameras or radio antennas would maybe help the mower in situations when the satellite signal’s too weak. Since it doesn’t have those, I’d have to set up no-go zones for the Sileno Free if it kept getting lost in the same place. On the flip side, this lawn-based Bermuda Triangle would never be mowed.
Either way, it turns out after a few weeks of testing that there are some spots in the garden that the Sileno Free won’t touch. Despite these areas being within the perimeter and the defined mowing zones. Is the Sileno Free so smart that it simply avoids the perimeter wall out of fear of losing its GPS signal?
The app’s sense of direction leaves a lot to be desired
Although the app maps show the outside wall of our house, you can’t see the garden wall, flower bed or terrace. How am I supposed to know how far outwards I can set a boundary point within the mowing area, for example?
It’s also pretty unhelpful that the robot lawnmower symbol on the map isn’t exact. Sometimes, the Sileno Free has already moved on to a different part of the garden than the one indicated by the app. This is down to delays in information transmission.
Robot mowers fitted with a camera or lidar have the edge in this respect, as they can capture and identify their surroundings themselves, making them capable of recognising lawn areas.
If you ask me, Gardena’s decision not to use an RTK antenna to optimise the mostly inaccurate GPS signal was dire. The manufacturer mentions its LONA technology, which involves numerous sensors in the mower collecting data. Algorithms and, of course, AI, then help improve the map. However, I don’t really notice the impact of this during my review. The Sileno Free hits the wall so often that its housing is already pretty scuffed and scratched after just two weeks.
How do I get the Sileno Free to trim edges?
Our lawn is surrounded by flower bed retaining walls. Thinking ahead, our clever landscaper placed a row of paving stones at the base of the walls to prevent grass from growing right at the base. This left a 10-centimetre gap between the wall and the lawn.
Or that’s the theory. It’s not clear to me from looking at the app or the device itself whether you’re supposed to activate this fancy feature specifically. There’s no menu item for it, and the instructions don’t elaborate any further on the information I’ve already mentioned. I assume that the crash with the boundary wall has let the control chip know that there’s an edge here.
Et voilà, the Sileno Free moves forwards towards the wall, makes a half turn, activates the smaller blade disc and cuts the grass in an elegant semicircular motion without leaving any edges.
The robot does an excellent job on the areas it mows. It cuts grass neatly, leaving the lawn at an even height. The Sileno Free is also pleasantly quiet – even more so than its predecessor.
What Gardena says about the problems I faced
Gardena says the GPS data isn’t precise enough for the Sileno Free to move around a defined working area to within a few centimetres. Only so-called correction data, transmitted from the Gateway to the mower, would make this possible.
After eight weeks of putting the Sileno Free through its paces, I finish my review feeling frustrated. Maybe the Sileno Free just doesn’t feel at home in our garden. It seems like raised flower beds, small walls or even a large, folded-up parasol are enough to stop it from maintaining a reliable satellite connection. The garage wall, house wall or wooden deck might present additional obstacles.
Who knows? Maybe a garden surrounding a hilltop mansion would be a better testing ground for the Sileno Free. I’m certainly not going to find out. Instead, we’ve put our old Sileno City back to work. I might be mistaken, but I feel like it stuck its tongue out at the Sileno Free as it made its way past.
In a nutshell
The Sileno Free still has a lot to learn
Only one aspect of Gardena’s robotic lawnmower meets my expectations: the results of the mowing process. The Sileno Free mows neatly and effectively, working until very close to the edges of your lawn. If it performed its fancy mowing moves in every part of our garden, I’d be able to retire my grass trimmer. The thing is, it doesn’t. Adjusting areas to be mowed, perimeter and zones in the app is fiddly, annoying and imprecise. However, its main problem – and the killer argument against buying the Sileno Free – is its very unreliable satellite connection. That was the case with my device, anyway. Once it’s been properly set up, a robotic lawnmower’s supposed to do its job automatically. The Sileno Free, by contrast, needs my help far too often. When it loses its bearings, I end up having to carry it back to the charging station. In my view, this is disappointing – especially when you consider the mower’s hefty price tag.
If your main priority is making sure the edges of your lawn are mowed better, the Smart Sileno Pro might be a better option. Although it needs a perimeter wire, it also has two cutting discs.
Pro
- Quiet
- Cuts well
- Mows very close to the edges of your lawn
Contra
- No obstacle detection
- Defining areas to be mowed in the app is cumbersome
- Stops randomly, and doesn’t make it back to the charging station
- Unstable satellite signal
Martin Jungfer
Head of Content
Martin.Jungfer@digitecgalaxus.chJournalist since 1997. Stopovers in Franconia (or the Franken region), Lake Constance, Obwalden, Nidwalden and Zurich. Father since 2014. Expert in editorial organisation and motivation. Focus on sustainability, home office tools, beautiful things for the home, creative toys and sports equipment.
