Lawnmower man

May 25, 2021

A year with a robot mowing the lawn.

Robot lawnmower, boldly going where no robot has gone before Robot lawnmower, boldly going where no robot has gone before

When we were blessed with a garden, it was made clear that mowing the lawn was not a thing we collectively would be spending time on. Thus, a robot lawnmower was called for. While I happened to have a friend more than happy to try and answer any questions I had, and while there were some amount of reviews and stuff out there to look at, I did not really find anything about what it is like to own and maintain a robot lawnmower, especially not over time.

Hello, I am Fredrik, and I have had a Gardena sileno something-or-other mowing my lawn for a year now.


You need one cable which surrounds your entire lawn, and which forms loops around any large objects you do not wish the mower to bump into all the time. You also need a second cable which starts from the base station and attaches to the outer loop at some distant point in the garden. The mower uses this cable both to efficiently reach the far corners, and to find its way back home when it is time to charge.

Gardena provided quite detailed instructions and manuals, which as far as I recall actually managed to answer most of my questions. Still, I am always a little nervous doing something like this where you need quite a bit of work before you know if anything works at all. Would I connect the cables poorly? Would I have accidentally damaged the cable as I placed it?

When I connected everything and plugged in power, I was dismayed to see the base station blinking in the way which indicates cable problems. Frantic cable inspections followed, but fortunately it turned out to be a really easy mistake. The connectors you use to patch the cable work by simply inserting the cable ends into holes, then pushing down a nice button-looking section to close and seal the connection. For my very first one, I had not pressed hard and evenly enough, producing a loose end. That button needs to pushed down all the way, and you can push as hard as you like. Once I did that, the system lit up and was ready to go.

The cables themselves are thin, but it seems hard to damage them without noticing. Even pulling them out of the ground works - at least with our ground, your mileage may vary and so on. I did accidentally pull one out of one of those connectors once, but I think that is the only time I have unintentionally caused a break, despite numerous dig actions and re-arrangements.

The game

One thing nobody told me when we bought the mower was that it comes packed with the game Cable hero. One might have thought that initial setup meant the end of most cable business, but no. The game has one initial phase, after which three different modes are unlocked. Switches between modes can be both sudden and planned.

The initial phase

This phase starts as soon as you finish basic setup. You have placed all the guide cables, found a suitable position for the base station, and actually got the whole thing running.

In the initial phase, the mower is actively looking for trouble.

You probably got everything in place nicely. But perhaps there is a spot on the lawn with just a bit too much elevation change (I have heard professional garden people refer to this as a "hole"). Perhaps the cable was just a tad too high off the ground in some places, where you ran out of staples and had no energy to dig it down. Or possibly, the cable ran a little close to some troublesome vegetation under a bush or something. Do not worry, the lawnmower will find those places for you. You will find it standing still, and you will have a feeling almost but not completely unlike a child on Christmas Eve as you walk over to find out what you will need to fix this time. A spare cable repair kit comes in handy.

At some point, the mower will have found all the places you missed. The initial phase will be over, and the three modes of the main game will be unlocked.

Mode 1: smooth operation

Yes, it happens. Frequently to some, more rarely to others. The mower goes about its business, finds its way back to charge, all day, many days. You become used to the lawn being set at a single height, and to the small robot quietly bumbling about, spending surprising amounts of time in a single corner yet managing to cover the whole surface eventually.

Mode 2: forced changes

Look, we have some new lawn chairs! We are building a deck! Let us plant a bush over there! That shrubbery needs to go!

Whatever happens in your garden, it now includes a step zero where you evaluate if and how it affects the lawnmower. Will you be digging where you might hit the cable? Will a new area need to be closed off from the lawnmower, or will you create new areas which should be cut? Even after the initial phase of the lawnmower cutting poorly placed cables, I have found myself patching cables surprisingly often to rearrange as needs change.

Mode 3: optimization

It might sound similar to forced changes, but if your mind has the right bent, there is a surprising amount of fun to be had here. That place where the lawnmower bumps into the patio? You could move the cable a little bit further out. That little patch of weeds under the big bush? Perhaps it would look nicer if you cut all that down and then rerouted the cable so the lawnmower covers it? Just before writing this, I cleared some ground and managed to both extend the cutting area, and eliminate a couple of corners for the mower to get stuck on at the same time. It feels dangerously satisfying.

In all phases, it has turned out much more useful than I expected to have the mower’s associated app installed. Getting a push notification whenever a new surprise occurs feels much better than finding out about it two days later, in the rain, or watching the lawn like a hawk all day.

Digging in

The lawnmower (at least ours) came with a rather big bag of staples for attaching the guide cables to the ground. There were almost enough of them for our whole garden, but I did end up buying another bag to have some spares for the inevitable changes.

If you are low on staples, the alternative is to dig. Having the cable underground is nice in many ways, the main downsides are that it is harder to find and - of course - a lot more work both initially and whenever you need to make a change. A nicely stapled cable gets covered by grass quite quickly, so you are not creating an eyesore by not digging either. (But it can get pulled by people or animals if you are unlucky. That somehow happened to us in a corner with particularly soft and muddy ground.)

Despite the downsides, I think I have dug down a lot more than half the total cable length by now. I started with a few uneven places where it took a lot of staples to get the cable properly close to the ground. Then I dug more and more whenever I was making changes anyway, and now I almost seem to have more staples in stock than when I started.

Do I like it?

Well, yes. Yes I do.

Even if it adds extra work and thought to any garden-changing activity, it is really nice to not be thinking about mowing the lawn all summer. Another major benefit occured to me as this season was starting: sound. When the neighbours started their gas-guzzling Mad Max-type monstrosities the roar filled the air like that of some ancient beast. Our little robot can tumble around on the lawn all day, and it takes a lot longer to get the job done, but it is so quiet it can actually sneak up on you.

Plus, it looks pretty cute and confused when it tries to random walk itself out of tight spots.

What could improve? More smarts, definitely. I would love to be able to provide or have the robot create a map of the garden and enable it to cut quicker and more precisely. Also, with good enough mapping, perhaps they could build a model which did not need so many darn cables …

(I am fully aware such models may even exist already. For the sake of the bank account, I refuse to research any further until the current one has worn itself down.)