15 things i wish i knew before i bought a robot lawn mower

15 Things I Wish I Knew Before I Bought A Robot Lawn Mower

There are a number of things that I wish I knew before I bought my robot lawn mower. Over the last few years, I’ve gained a lot of experience with these machines, and I’ve discovered a lot of things, both positive and negative which would be useful to anybody considering getting one.

This article discusses 15 things, both positive and negative, that might help you benefit from my experience with robotic mowers.

Flymo 1200R Robot Lawn Mower

1. Robotic Mower Installation Takes A Bit Of Time

Prior to purchasing my first robot lawnmower, I really didn’t have a lot of knowledge or experience of these machines.  I assumed that there would be very little setup involved in getting a robot lawnmower up and running. I thought that it would just be a matter of charging it up, programming a few settings and letting it begin to work.

The reality is, because robot lawn mowers use a perimeter wire  to detect the edge of your lawn, you must spend some time installing this prior to using your machine. The setup process will take a few hours, but it is quite simple and can be done by anyone, regardless of expertise. Once the setup is complete, there is very little input involved in running a robot lawn mower. Check out my experience of installing and using the Flymo 1200R Robotic Mower here.

2. Your Lawn Will Look Better

Due to the way robot lawn mowers are designed to work, your lawn will be much greener and healthier, with fewer weeds, and will look  neatly cut all the time.

I really like my lawn to look well. I used to spend quite a lot of time applying fertiliser and weed killers, manually removing weeds, aerating and dethatching my lawn. Unfortunately, my actions were contributing to the poor condition of my lawn and to the establishment of weeds.

I didn’t have time to cut my lawn frequently enough to keep weeds at bay. I removed the cuttings every time the grass was cut, which removed essential nutrients from the soil.

After applying fertilizer, my grass would be weed free and vibrantly green for a few weeks, but then it would slowly become less vibrant and weeds would re-establish themselves.

Robot lawn mowers have three main mechanisms to make your grass look better.

  1. They mulch the clippings. Instead of removing the clipping and therefore the nutrients from the grass, the clippings are mulched into very fine pieces and are returned to the lawn. As the clippings are so fine, they drop down to soil level, where they are able to return their nutrients to the soil for the growing grass to use.
  2. They cut the grass very frequently. Due to the frequent cutting of the grass, weeds simply cannot establish themselves and you will notice after a few short weeks of using a robot lawn mower that you have fewer weeds in your lawn.
  3. As robot lawn mowers cut your lawn so frequently, the lawn will always look freshly cut. There will be no uneven growth. Your lawn will look perfectly flat and immaculate all the time.

Considering the effort I put in with my lawn prior to getting a robot lawn mower, it was bittersweet that a robot lawn mower so effortlessly kept my lawn looking vibrantly green and healthy. Below is a before and after photo of my lawn.

my flymo 1200r working away in the rain

my lawn before robot lawn mower

3. You’ll Spend All Your Time Talking About Robotic Mowers

People who come to my house usually notice my robot lawn mower out the window and want to ask about it. They always find it quite amusing and interesting, as they are still quite uncommon. I’m more than happy to talk about my experience of having a robot lawn mower, both the positives and negatives.

My children are also fascinated by the robot lawn mower marching around the garden, so they like to give me a running commentary on what it is up to. Whether you see this new conversation topic as a positive or a negative will depend on you.

4. Lawn Obstacles Are No Problem For Robot Mowers

Prior to purchasing a robot lawn mower, I was concerned that it would not be able to navigate around temporary obstacles on the lawn and that this would create hassle by having to ensure that the grass was clear at all times. Thankfully my research before purchasing reassured me, and I have had no problems with lawn obstacles at all.

Robot lawn mowers have been developed to navigate around obstacles on your lawn extremely efficiently. Permanent obstacles can be marked out with the perimeter wire, ensuring that the robot lawn mower will not come into contact with them. However if there are obstacles on your lawn that are not marked out by perimeter wire or are only temporary, this will be no problem.  

All robot lawn mowers have collision sensors and operate at very low speeds. There is no prospect of damaging an obstacle on your lawn. The robot lawnmower will simply come into contact with it, turn around and go in a different direction.

Certain obstacles must be marked out by perimeter wire. These include flower beds and ponds as the robot lawn mower will simply drive into these if they are not marked out unless there is a raised boundary.

5. They Can Handle Lawns Split Into Sections

Robot lawn mowers are all very well if you have a regular shaped lawn in one section, but what if your lawn is quite a complicated shape or if it is split into two or even more sections of grass? There’s not much point in having a robot lawn mower that will only cut one area of your grass but leave you having to cut the other areas with a conventional lawn mower.

Thankfully, complicated lawns are normally no problem for robot lawn mowers. Lawns split into several sections can be managed by almost all robot lawn mowers, but it may take some planning to get the best setup.

One of the easiest strategies is simply to extend the perimeter wire around the second or third area of grass in a continuous loop. The manual will explain how to do this very well. Usually this involves lifting the robot lawn mower between the two sections of grass as required. However, you’ll need to lift it back to the charging station manually. This isn’t the best option, as one of the key benefits of having a robot mower is that you’re not meant to have any input with cutting your grass.

Another option is to purchase a second charging station so that the lawnmower can be lifted from one section to the other as needed, perhaps once or twice per week. This will let it work and charge autonomously, and the only input from the user is to lift it between sections of grass as required.

A third strategy is to purchase a second robot lawn mower. This sounds crazy, but can actually be a cheaper option for some. There are some very good value robot lawn mowers that can manage lawns of up to 600 sqm. These are often less than half the price of models that can manage 1000sqm. If your lawn is split into two fairly equal sections, this would work well. You may forego some of the smart features of more expensive robot lawn mowers, but I would strongly advise that having your grass cut completely autonomously is a much better option.

This Is a strategy that my father has employed in his garden which has a section of lawn at the front and the back. He has one robot lawn mower which cuts the front lawn, one which cuts the back lawn. He uses two Flymo 1200R models and it has worked flawlessly and is actually cheaper than a model which would be sufficient to cut both areas.

6. Burying The Perimeter Wire Is The Best Option

installing robot lawn mower perimeter wire

There are two options for the installation of the perimeter wire around the edge of your lawn.

One option is to peg the perimeter wire to the grass. The second option is to cut a small slit in the ground and bury it between 5 and 10 centimeters deep.

Whilst pegging the perimeter wire down is a quicker option, I would argue that it is a significantly worse option. When you peg the wire down, it should sit flush with the grass. Over the first few weeks, there is a risk that the growing grass will push the wire up into the blades of the robot lawnmower causing a perimeter wire break or damage.

For this reason, you must run the blades of your robot lawn mower at the highest setting and slowly lower them until you achieve the desired cutting height over the space of a couple of weeks.

Eventually, the perimeter wire will disappear from view, as the grass grows over the top of it. This will take approximately four to eight weeks. Pegging the perimeter wire to the ground limits your ability to do grass maintenance activities such as aerating and dethatching your lawn, due to the risk of damaging the perimeter wire.

If you bury the perimeter wire you will be able to carry out routine lawn maintenance without fear of hitting or damaging the perimeter wire.

The downside of burying the perimeter wire is that adjustments are sometimes needed in the first few weeks of operation of a robot lawn mower.

In my experience I put the perimeter wire to close to some flower beds, which led to the robot lawn mower falling into them. I had to move the perimeter wire a few centimeters further from the flower beds to ensure that the robot lawn mower did not get stuck.

I think the best thing to do with the perimeter wire is actually to peg it down initially, ensure that the robot lawn mower is running flawlessly over the space of a few days or perhaps a week, and then bury the perimeter wire. This is done by going round the edge of your lawn and creating a thin channel with an edging tool and putting the perimeter wire into it. It really doesn’t take too long.

I would advise that you bury your perimeter wire when the ground is wet, after a period of rainfall. This will make sure that the ground is soft and it is easy to cut into with an edging tool or straight spade. I would not want to be doing this job after a long drought with rock hard ground. If these are the weather conditions when you are installing a robot lawn mower, just forget about burying the perimeter wire until a later date, or soak the ground with water and leave it for a few hours to soften up.

7. Most Robomowers Wont Cut The Edges Of Your Grass Perfectly

Unfortunately there are a few drawbacks of robot lawn mowers due to the current technology used to detect the edge of the lawn.

Whilst robot lawn mowers will cut right up to the edge of your lawn where it meets paved areas, they will not usually able to do this next to flower beds or ponds. The robot lawn mower will leave a narrow strip of uncut grass. You will then have to manually trim the edges with an edge trimmer. This doesn’t have to be done very often, and I usually do it about once every four weeks.

This is a significant negative aspect of the current generation of robot lawn mowers and one you should be aware of before making a purchase. It should be noted that certain models are better at doing edges than others. Typically the cutting technology from Robomow robot lawn mowers is better suited to getting closer to the edge of your grass. However I still don’t think it negates the need to trim your edges.

8. Robot Mowers Are The Future

One concern I had about robot lawn mowers was whether they would work as well as conventional lawnmowers. Thankfully, I need not have been concerned as my robot lawnmower does an excellent job, and the feedback from most users is generally good. Personally, I could never go back to a conventional lawn mower having used a robotic mower.

Generally robot lawn mowers live up to their promise of being able to delegate your lawn care to a robot. They still have a few minor issues which do not significantly detract from the generally positive experience. The two main things to be aware of are that the set-up is a bit time consuming and robot lawn mowers generally won’t do a perfect job on your edges. As long as you keep these two things in mind when you buy robot lawnmower you are generally going to be pleased with your purchase.

The technology behind robot lawn mowers has been in development for over 50 years, with mainstream domestic machines widely available for over 20 years. During this time the technology has gradually developed and come down in price, meaning that a lot of the problems that were present in the first robot lawn mowers have largely been solved.

9. Robot Mowers Are Safer Than Conventional Lawn Mowers

The safety aspects of robot lawn mowers cannot be overstated. Conventional lawn mowers are consistently the most hazardous piece of garden machinery in use today.

Over 80 thousand people attend the emergency department each year in the United States with a lawn mower related injury. Certainly, when I used to use a conventional lawn mower, the poor safety record of these machines was never far from my mind and probably played a role in the decision making process causing me to make the switch.

According to one of the leading manufacturers of robot lawn mowers, a robot lawn mower has never caused an injury resulting in attendance at an emergency department. I think this is a staggering statistic if it is true. From my research I have not been able to disprove this. Certainly there are multiple reasons why robot lawn mowers barely comparable in terms of safety compared to conventional lawnmowers.

Robot lawn mowers use much smaller, lower powered blades. The blades are tucked well under the machine and the user does not have to go anywhere near them while the robot lawnmower is an operation. Robot lawn mowers have lift and tilt sensors and will initiate an emergency stop of their blades in a fraction of a second if there is any interference with the machine which could result in an injury. Read more about the safety aspects of robot lawn mowers here. 

10. They Can Work Out Cheaper

Robot lawn mowers generally have a reputation for being very expensive. The cheapest models retail for approximately £400 in the UK and the top of the range domestic models cost about £3,100 in the UK. Prices in other territories are broadly similar. This puts the ticket price of robot lawn mowers higher than conventional rotary lawnmowers, but broadly in line with the more sophisticated cylinder lawn mowers. 

However, robot lawn mowers are cheaper to run and have lower maintenance costs. Over the lifetime of the robot lawn mower, it is likely to cost a very similar amount to a conventional lawnmower, and in some instances may work out cheaper. For those people who pay a gardener to cut their lawn, the payback time for purchasing a robot lawnmower can be as little as one year. I’ve written an article about how robot mowers can be cheaper than conventional mowers.

The high initial cost of robot lawn mowers may deter some people until the costs decrease further, but in many cases they are already comparable with conventional mowers. The price of robot mowers has been falling slowly and steadily over the last 10 years and is likely to continue to do so, but at a slower pace.

11. They’re Not As Smart As You Think (But This Isn’t A Bad Thing)

Maybe it’s just me, but when I think of robots, I think of sophisticated machines that use artificial intelligence to automate jobs that humans do not want to do. The reality is that robot lawn mowers are really very basic. It is entirely possible with today’s technology to build a robot lawn mower that will automatically sense the edge of your garden without need for a perimeter wire, and will use visual systems to detect when your grass needs cut.

However, to build such a robot would be very expensive and would contain a lot of complicated technology. This would put the price out of the range of most consumers and would increase the risk of component failure, causing them to be less reliable. The reality is that the designers of robot lawn mowers have opted to aim for a machine that will do an acceptable job, while keeping the complexity and cost down to an acceptable level. 

If you have ever watched a robot lawn mower, you will notice that they usually work in a random pattern. The controller chip on a robot lawn mower uses an algorithm to determine what way to turn and react to obstacles. This ensures that the probability of the robot lawn mower covering each area of grass at least once, reaches 100% within a reasonable amount of time. You will also notice that this leads to some areas of grass being covered many times, before other areas are even cut once. This is very inefficient, but is computationally undemanding, reducing the complexity and cost of the computing power required for the robot lawn mower.

It would be so much better if the robot lawn mower mapped your lawn and then simply followed a pattern to ensure that the entire area of grass was cut once per cycle. This could either be in stripes or in another efficient pattern. Unfortunately, the current range of robot lawn mowers do not have this level of complexity for the reasons outlined above.

No doubt, the capabilities of robot lawn mowers will increase over time as costs fall and technology is able to be implemented in a competitive consumer product. If you want to read more, I’ve written an article about how robot lawn mowers work.

12. Damaged Perimeter Wire Is An Easy Fix

The perimeter wire is used by the robot lawn mower to detect the edge of the lawn. This can be at risk of damage for a number of reasons. Burrowing animals, the robot lawn mower itself, gardening activities, and even freeze-thaw conditions can lead to damage or breakage of your perimeter wire.

Even if you only pegged the perimeter wire down, the breakage may not be visible at first sight, as the grass will have grown over the top of it. One of my major concerns was that if a breakage were to occur, how on earth would I find where the breakage was. Sometimes the break in the wire is very obvious to see If damage has exposed part of the wire above the surface of the grass. However, in other circumstances, even after inspecting the entire perimeter of your grass, there will be no clue as to where the damage is.

I thought the only option to find the break would be to pull up the perimeter wire until the break was found. After repair, this would then involve re-laying the perimeter wire, which is quite a time consuming process.

Thankfully, there are a number of techniques which can be used to locate the perimeter wire which negate the need to pull up a significant proportion of your perimeter wire. There is one technique in particular, which is not outlined in the manual of robot lawn mowers, but which works extremely well and will avoid you having to dig up more than perhaps 6 inches either side of the breakage.  I’ve written an article which outlines all the techniques to locate and fix a break in your perimeter wire.

Repairing a broken perimeter wire only requires a few minutes and a single wire connector. It is normal for several spares to be provided in the contents of the box of your robot lawn mower. These connectors allow you to very easily connect two or three wires together in a matter of seconds. The connector can then be buried a few centimeters under the grass, so there will be no visual sign that the break occurred.

13. You Don’t Need Expensive Manufacturer Branded Spares

Spare blades, wire connectors, perimeter wire and batteries are widely available through robot lawn mower retailers and online. Typically, branded spares can be quite expensive. I have found that there are a wide variety of compatible spares which are considerably more cost-effective.

My own robot lawn mower is made by a brand that is owned by Husqvarna. The spares are largely the same as the spares for other Husqvarna robot lawn mowers.

I have had good experiences buying compatible spares on Amazon, which generally work out at less than half the price of the branded spares. Having used the spares on numerous occasions now, I do not see any difference in the quality compared to official branded spares. You may feel uncomfortable using compatible spares due to the potential impact that this can have on a manufacturer warranty. You may wish to transition to compatible spares once the robot lawn mower is out of warranty. 

14. Mulching Clippings Is A Good And Bad Thing

Robot lawn mowers do not collect your grass clippings. Instead, they mulch the clippings and return them to the lawn. As robot lawn mowers are designed to cut your lawn very frequently, the clippings are very fine and fall into the lawn and onto the ground, rather than clumping together and sitting on top of it. This means that the clippings will generally not be seen and your lawn will look tidy. If you were mulching your clippings with a conventional lawn mower, you would find big clumps of clippings would sit on your grass and the lawn would look quite unsightly.

Mulching your clippings is a positive thing for a number of reasons.

  1. You do not have to collect the clippings. Previously, all my grass clippings would have gone in my garden waste bin, or have been taken to the recycling centre directly. I would frequently run out of room in my garden waste bin, and the only option would be to take the excess clippings and garden waste to the recycling centre. This used to eat into my free time, so I am glad I no longer have to do this.
  2. Mulching means that the nutrients that are in the clippings are returned to the soil. Once the clippings start to break down, the nutrients then become available for the growing grass to use. This means that you will have to fertilise your grass much less frequently. When I used to use a conventional lawn mower, I would have spread fertiliser on my grass approximately 4 times per year, to try to keep it looking green. The grass would look great for approximately 4 weeks, after which time it would get less and less green and vibrant, which was very noticeable after each cut. Since getting my robot lawn mower, I normally fertilise my lawn twice per year, once in the spring and once in the autumn. Not only does this make caring for my lawn easier, but it saves me a fair bit of money that I used to spend on fertiliser.
  3. Your lawn will look better. Mulching your clippings makes your lawn look better for a number of reasons. Following on from the last point, as you are not removing any nutrients from the soil with a robot lawn mower, the growing grass has more available nutrients, so will be greener and more vibrant. As robot lawn mowers work more frequently, ensuring that the clippings do not clump up on top of the lawn, your grass will always look freshly cut, My lawn is much healthier and greener than it ever was with a conventional lawn mower and requires minimal effort to keep it this way.

There is one negative point to mention about a robot lawn mower that mulches your clippings. Although the clippings won’t generally be visible, they have not disappeared into thin air. I find that when my kids play on the grass, they get far more grass clippings stuck to their shoes than they would have done when I had a conventional lawn mower.

They then have a tendency to bring these clippings into the house on their shoes. Whilst we previously had a loose, “shoes off at the door policy”, we now have to enforce this strictly, to ensure that grass clippings are not brought into the house.

15. Robot Lawn Mowers Are Durable And Easy To Maintain

Robot lawn mowers are mechanically much simpler than conventional lawn mowers. Conventional lawn mowers which use internal combustion engines and heavy duty cutting mechanisms have far more moving parts that are at risk of breakdown or failure. These need regular maintenance to ensure that they remain in working order. Robot lawn mowers use electric motors, lithium ion batteries, and very simple cutting mechanisms.

For this reason, the maintenance requirements of a robot lawn mower are considerably less than a conventional lawnmower. Typically, you will have to clean the underside of your robot lawnmower every few weeks to ensure there is no excessive build up of grass clippings. You will have to change the blades of your robot lawnmower according to the manufacturer’s recommendations.

A point to note is that most manufacturers recommend changing their blades a bit more frequently than I feel is actually required. The manual for my robot lawn mower recommends changing the blades every 8 weeks. I change the blades of my machine approximately twice per cutting season,  as I don’t notice a major deterioration in cutting performance or the appearance of the lawn when the blades are dull.

I have never had my robot lawnmower professionally serviced, and I have never had any problems with it. I simply keep it reasonably clean during the cutting season and do a more thorough clean prior to winter storage. I use a little bit of WD-40 around the wheels and moving parts. The battery will need replaced every 3-5 years depending on usage and your individual battery. You can usually tell when your battery needs replaced as the cutting time will decrease significantly. This is the time to go ahead and order a replacement battery, rather than waiting for the battery to fail completely.

This is one of the most expensive spares you will need, but again, I would recommend not opting for the official spare. The official branded spare battery for my robot lawn mower is approximately £90, but compatible alternatives are available for as little as £40.

Many thanks for taking the time to read this article. If you have any questions, please let me know in the comments section below. I would be delighted to try to help. If you want to learn more about robot lawn mowers, the features to look out for and some suggestions for the best ones to go for, check out my guide here.