1 Week Impression of the Husqvarna Automower 450x on a Golf Course Fairway

Last week we (fellow superintendent) got the first automower in Western Canada to be used on a golf course (from what we can tell).

I've talked a lot about robot mowers recently and how they could potentially benefit golf with mower savings of up to 50% but more realistically 20-30%.

Micah Woods also recently wrote about how they are more energy efficient and can help reduce GHG emissions even when the electricity comes from coal.

So in theory these machines could be a game changer for golf and turfgrass management. They are also the best solution to transitioning off fossil fuels without having to spend a fortune on big electric mowers.

Even though these mowers have been used for quite some time in golf, there is little information other than a few youtube videos and my blog posts. So we decided to give one a go and see for ourselves how it would work and share the experience.



The superintendent who is testing out the mower set it up on one of his fairways. We set the HOC down as low as the machine would go to 2cm. Modifying the HOC lower would not be difficult with a few shims but as this is only a demo machine, we cannot modify it.

Setup was very easy with the wire being strung around the perimeter and fastened to the turf with plastic pegs. For a permanent installation I would install the wire under a narrow layer of sod to protect it from golf club swings. Make sure you lay it where you want it otherwise you will be doomed to ugly cleanup cuts for ever!

Cleanup cut is rough at first but once the machine follows wire back to charge it cleans up nice.

The first thing we did after opening the box was take it apart!

The blades are small razor blades that are double-sided. The machine can rotate either way to maximize blade life.

Modifying this to cut lower would not be difficult.

After that you just let the machine go and to be honest, it's not that impressive, but in a good way. To see this little machine bounce around the area is not very fantastic,  but after a week I returned to see that the grass looked exactly the same as when I last saw the machine. Whoa, it works!

Not bad for no human input after one week of good spring growth.

The cleanup cuts were impressive as the machine uses the perimeter wire to find its was back to the charging station.

When someone touches the machine it lets out a super annoying alarm and instantly notifies the owner via text message.

Turf quality is OK. I won't say it's GREAT because it isn't. At only 2cm the height just isn't low enough for premium fairway turfgrass in my opinion although it's surprising good for being so high. The logistics of how these machines work are very interesting. They aren't like conventional mowers where there is a certain capacity per hour. These mowers have a total capacity period, no time limit.

The way they work is they bounce around the area for about 20 hours a day. The rest of the time they are charging themselves on the docking station. So during that 20 hours, they mow almost all of the area at least once, and a lot of the area more that once. When you think of it, the area down the middle will have the machine pass over it multiple times each day as it zig zags down the fairway.

You see on your phone where your robot has been. 

We can do a little math here. It mows at about 3000 meters per hour. The blade disk is 0.24 m wide. That means it cuts about 720m^2 per hour. It mows 20 hours a day so it cuts about 14,400m^2 per day. The capacity of the mower is only 5000m^2 a day so how does that work? According to this math it could cut 3x the area.

Because the mower doesn't work like conventional mowers that only cut grass once, it covers a lot of the areas a few times a day.  I estimate it to mow a given area about 3-5x a day. There are few courses I know of that cut that often! There area  few reasons they do this. 

Simplicity: It is way easier to have a mower just "randomly" drive around than drive super specific paths with little overlap. This is why the conventional robot mowers you see are so expensive and have such a low capacity. They are super complicated machines. The automowers are super simple machines.

Efficiency: It takes a lot of power to cut long grass. This is why our big rotary rough mowers have such big engines and require so much fuel. The costs goes up further with tier 4 emission regulations for high horsepower engines. The robots need to be super energy efficient to be fully electric, small, and affordable. Therefore they cut the grass super frequently to only take a little grass off at a time. This allows them to maintain a relatively large area almost constantly with little power required. It also allows them to use cheaper and smaller batteries which are still quite expensive.

As we aren't paying a person to operate this mower, the time it takes is irrelevant. The machine is almost silent and we have had no comments from golfers over the past week. As I said earlier, these machines are not very impressive at first glance. They just trundle along.

It just happens that for a lot of courses the capacity of this mower will be the size of the average fairway.

These mowers have a very small wheel base similar to that of a reel type mower except the blade disk is on an angle so the only part that cuts is directly between the front wheels. Our test site is a fairway that is very bumpy and this machine scalped long turf in the BOTTOM of a few dips that the conventional mowers couldn't reach. No scalping on the tops so far.

scalped turf on the BOTTOM of a dip that reel mowers couldn't cut.

The way height of cut works with these mowers is also different than conventional mowers. 

You might set your HOC at 12 mm with a conventional mower and go cut the grass. Immediately after mowing that is about the height of cut you get, but as time goes on, it gets higher and higher. How high is the grass when you mow it again? If you figure this out you can calculate what your average HOC is with a conventional mower because that's all it is. An average over time.

With the automower the HOC is the HOC. As discussed above, most of the area gets cut multiple times a day so the HOC stays the same. This allows you to maintain a similar average HOC as conventional mowers with a higher bench height setting. It's weird to think about but that's how it works. Also, no clippings!

Automower on the left, unmown middle, conventional reel mower on right.

As I mentioned, the turf quality wasn't what I would expect on premium turfgrass. Obviously the height needs to go down.

There is also no striping so the grass grain really shows up and looks a bit mottled. This could be fixed with a weekly roll which would give you many more benefits to just mowing such as reduced disease, more consistent appearance, and a quick and cheap process.

We are going to test this machine out for a few more weeks on the fairway and will then move it to some high profile rough.

This now has me thinking of how to optimize the area that each of these mowers can cover. Below is an image I put together with theoretical areas each mower would maintain. When doing this you want to have as many different areas to intersect at one given location to minimize the amount of power wire you need to install for the charging stations. If you have satellite irrigation controllers you already have the power wire installed so what are you waiting for?

These machines are ready for golf out of the box. While not for premium turf, they would be more than adequate for most courses and with a few modifications would be even better. They offer huge advantages to an industry facing labor shortages, rising mower costs and rising fuel costs. With these mowers we can allocate our staff to do the important jobs we used to do before the golf industry entered the recent decline.

Turfgrass Speedo

How fast should we grow our grass? It's a question I have been asking on this blog for almost 7 years now and every year I think I get a bit better. I explained this evolution last year in a blog post called "The Evolution of Precision Fertilizer Application."

No, not that type of speedo Source: https://www.youtube.com/watch?v=rFmcO1aDUnE

Even as I progress I still admit I have absolutely no clue what I'm doing when it comes to driving turfgrass growth. There are many clues as to the ideal growth rate. I wrote about that in a post called "
Using indicator species to fine tune fertilizer applications."

Could a tool like this help me grow grass at the right speed?

Basically, I have this feeling that achieving the optimum growth rate will make a lot of our issues less severe but figuring out what that speed is has been a challenge. Every year is different so what worked this year certainly won't work next especially if you are looking to really fine tune things to an extreme degree like I have been playing around with.

Tools like the growth potential have been a big help but again, they don't tell me how fast I should grow my grass.

Clipping volume has been a tremendously useful tool to understand the health and vigor and differences in how my grass grows. It has given me clues that growth rates matter. But again, I still don't know how fast I should grow my grass.

At times I require a lot of fertilizer to get the grass to grow and at other times it grows much faster than I would like despite applying hardly any fertilizer. 

Here's the thing. Growth doesn't just rely on how much fertilizer you apply. Adding nitrogen fertilizer can do one thing, make grass grow faster.

Sure we can use growth regulators to grow the turf slower but I also wonder that if we are acutely aware of how fast our grass is growing then why can't we grow it at an appropriate speed without having to spend more money putting the brakes on?

The can of worms opens wider. What is an appropriate growth rate? It depends! How much traffic do you have. Do you want to manage for playability first or plant health first? Every course is different so no one can make a generalization on how much nitrogen to apply.

You start to see why I am so confused with this. There is simply so much we don't know about things as simple as how fast we should grow our grass because it is such a difficult question. I do think, however, that it's a question worth looking into and trying to solve. The benefits of getting it right all the time could be huge.

While working on a presentation about precision fertilizer use for the greenkeepers in Denmark last month I thought of a new way of using the clipping volume and growth potential tools to potentially give me better insight into how fast I should grow my grass.

What if we combine growth potential with #ClipVol ?

Just like I have used growth potential to estimate how much nitrogen I should apply in the past we can use it to estimate how much grass we should grow and it's actually pretty easy especially if you use my turfgrass weather modeller. 

We simply multiply the growth potential by the maximum growth rate we would ever want to see on our course.

Say the maximum amount of grass you would ever want to harvest in a month is 500ml/m^2. If the monthly growth potential was 50% we would expect to harvest about 250ml of grass/m^2 that month.

That's all fine and dandy but that still doesn't help us know how much fertilizer to apply.

What if we compare the ideal amount to the actual amount. So if we wanted to grow 250ml of grass but we harvested 400ml that would be 400/250 = 1.6. Basically we are growing the grass 1.6 times too fast and we need to back off on the nitrogen fertilizer.

We can compare this number over any time period and it's a feature I added to my Turfgrass Maintenance HUD recently.

Below you can see that addition. On the upper chart you can see the monthly clipping yield compared to the ideal yield. The absolute value doesn't matter. What matters is how close to the ideal amount you are. Generally I've noticed that the further I am from the 1 or yellow line, the more conditions suffer. This chart can also show you when what you are doing to push growth is working even though it might not seem that way. In March 2017 we were recovering from winter damage and even though growth was slow, you can see it was WELL above normal. The extra fertilizer and tarping worked!

The lower gauges compare the actual vs ideal growth rates over varying time frames and could possibly help me make better decisions on how much I need to push or slow growth. We haven't mowed this month yet so obviously there is no recent data. Last month I grew that grass too fast and had some issues with microdochium. But over the last year I grew that grass almost perfectly overall. There were peaks and bumps in the road that certainly caused some issues but overall it was a good year.

The new superintendent here also noted that the greens were really nice and green. They might look nice but there's a cost to that colour in December!

Lush greens in December can be a problem

To determine the weekly ideal harvest we would divide the monthly maximum by 4. Daily by 30.5 etc and compare it to the actual yield.

If we are going too slow we can add more fertilizer, if we are going too fast we can apply less. I think there might be value in having an awareness like this.

The monthly maximum will vary from course to course. I came up with a monthly max of 625ml based of my historical data.

Anything more than that is excessive and actually achieving that level should be impossible because no 30 days in a row are exactly at 100% growth potential. Of course we could go higher if growth rates explode like they did last summer.

You can use monthly yield data to determine how much is too much. Last August was way too much but July was just about right for my course's specific needs.

This gives you a hypothetical turfgrass growth speed limit and shows how fast you are going compared to the limit you have set for yourself adjusted to the actual weather conditions. Nothing is based on the date on the calendar but more on actual growing conditions. Then if you feel growth rates are too high you simply adjust the monthly maximum number and this will adjust across all your data.

The amount of nitrogen we apply doesn't really matter. What matters is results. What matters is growing the grass at the appropriate speed and I have a hunch that this might be the best method yet of figuring it all out and achieving better results more consistently but I don't know, it's winter and I have 4 more months to go before the grass starts growing again. As usual I am already excited for next season's grass growing.

Addressing Climate Change in Golf

One of my favorite things to do is a SWOT analysis. It's where you look inward and outward to address the Strengths, Weaknesses, Opportunities and Threats that you or your organization face. I do this almost continuously although I do a more formalize version every winter.

Back in 2011 one of the biggest threats to golf course operations was a cosmetic pesticide ban. From that time on I took the approach of trying to figure out how I could address this threat by figuring out ways to reduce my reliance on pesticides. While the threat has lessened slightly, I am also less worried that I was back then because I took a proactive approach and learned a few things along the way. I still think there is value in taking this threat seriously though.

Another threat the golf industry faced over the past decade was the recession and financial difficulties. Again, I took the approach of finding solutions to this problem while sharing what I learned here.

In the coming decade I think the biggest threat to golf course operations will be climate change. You might think that it will be the warmer temperatures or the wildly variable weather your course might experience and these are very valid concerns. To me, though, the biggest threat surrounding climate change will be increased costs of fuel and equipment as stricter carbon taxes and regulation come into play.

It seems that in the last 6 months or so the urgency of climate change has intensified although it varies depending on who your government is. This adds another level to the threat. Things could drastically change depending on who is in power. One day you might be fine with your diesel burning mower and one day it might be illegal to use. That's an extreme example but the threat we face is also extreme.

Just like they tried to ban non-essential pesticides back in 2011, what if they try and ban non-essential fossil fuel uses in the near future?

If the price of fuel doubles in the next 5 years will your course be able to adapt?

If the cost and complexity of fossil fuel burning mowers increases even more will your course be able to adapt?

How big of an increase can your course manage without going out of business? If you are looking towards the future and take any possible threats seriously you need to know this figure. How much can you afford? At what point will you be forced to change or close the doors? Maybe you are already there as the cost of mowers is bordering on insane these days!

When we plan out our equipment plans we often look 5 to 10 years into the future. What does that future look like? With the recent pace of change your current plans might look a lot different than they did even a year ago.

Just as I always have, I plan to take a proactive approach to this threat to my business. The first step is to investigate alternative ways to do our jobs without fossil fuels. I have already used battery powered string trimmers and 3 years later the machine and battery still work great for all but the thickest and heaviest of weed whacking jobs.

The second step is to try out and adapt the current technology to our needs. In my opinion there isn't yet a perfect solution but that will change as innovative superintendents get their hands on these new autonomous mowers.

I am extremely excited about the potential that small autonomous mowers will bring. They can mow relatively large areas with the current battery technology and don't require a huge investment to implement.

Video van all wheel drive Husqvarna robotmower pic.twitter.com/9cTexsw0Ln

— Hein van Iersel (@HeinvanIersel1) October 9, 2018

They promise to solve a lot of the issues we face but the biggest threat they will help us manage is the threat of using fossil fuels to do our job because they are 100% electric. After learning how these mowers are successfully used in Europe already, I am no longer worried. I am excited for the future and challenge of golf course maintenance without fossil fuels.

If someone came to us tomorrow and said you can no longer use diesel or gasoline to maintain your golf course we would have a solution. It would take some creativity to implement but it would be possible and for relatively low costs.

This blog has beat the threats of pesticide bans and tough economic circumstances almost to death. While I will continue to focus on these threats I think that it would be irresponsible to ignore the threat of climate change and how we can make the transition away from fossil fuels as painless as possible.

Implementing this at my new course probably won't happen as quickly as I would like but a neighbouring course ( and hopefully my old course) will be trialing this technology in the new year and I will share everything we learn so that others can also get in early and do something about climate change in golf.

More Crazy Robot Mower Ideas

Recent discussions on twitter have drummed up a lot of interesting ideas about robots and a lot of hate too!

I love it!

For the haters or skeptics think about robot mowers like this.

Do you have an irrigation system with valve-in-head rotors? Do you have a central control? If yes, your biggest piece of equipment on your course is already a robot.

Afraid robot mowers will take away jobs? How did our current irrigation system technology affect jobs of people who used to manually plug in quick coupler heads all night long? Are you willing to go back to the way it used to be with irrigation? Didn't having actual people manually plugging heads in give it that personal touch that is lost with today's "automatic" sprinkler systems? Don't you think that the precision that modern irrigation systems bring makes golf better? Don't you think that trained and skilled people are still required to operate these highly efficient marvels of irrigation technology?

Just as it is seen today to be better to spend time fine tuning the irrigation system run times instead of spending time just simply turning them on and off again, the same will be true for robot mowers.

Did anyone imaging that we would one day be able to control thousands of sprinkler heads with extreme precision with a computer we hold in our hand?

I think the same big shakeup is coming to mowers sooner than everyone thinks.

Just like with our current irrigation systems, maximum efficiency is found with many heads that distribute water over a smaller area. The same will be true for robotic mowers. Instead of having 1 or two fairway mowers like we have today, we will have hundreds of small battery powered machines.

If one of them breaks down the rest of the "swarm" will be able to pick up the slack. Today, if your only current fairway mower breaks down, nothing gets cut until it is fixed., robotic or human powered.

One big mower is expensive. Many smaller mowers will be easier to start small with and expand their usefulness in small increments. There will be no need to go all in right away. As people are hesitant to adopt the new robotic technology. This will allow them to take baby steps

We won't have mowers that are dedicated to a specific area of the course. Instead, they will have variable heights of cut and will adjust as they enter different areas of the course. Think of the robots of being like a CNC machine today. They will roam the property at times that you specify and will adjust the HOC as needed depending on their current location.

Just like irrigation systems that are designed with a specific water window in mind. We will design these mowing systems with a mowing window. The number of robots that you require will be based off of the time you wish to spend mowing each day or night.

These mowers will change golf course architecture as well. How much of our current golf course design is based off of the needs of irrigation, drainage and mower capabilities? As mower capabilities change we can only expect the course designs to change as well.

Our current mowers have rigid heights of cut. Sure we can adjust them from day to day but they cannot generally be adjusted as we mow. This leaves course areas defined by the height at which the grass is cut. Greens are the shortest, Tees and approaches are a little higher, fairways are higher yet and finally there is the rough. Some courses even have intermediate rough and naturalized areas which aren't mowed at all.

Are rigid height of cut transitions because it's what's best for the game or because it's only what is possible with our current mower technology?

With robot mowers we won't need to define areas like this. We will be able to have soft transitions from one area to another. Focusing on technology that allows robots to mow super precise borders is nice but probably not needed except for maybe the edge of greens although Chambers Bay had no defined border on their greens for years. This feature is needlessly complicated and slows the progress of these mowers. It's probably not needed.

Course architects will be able to design holes with variable heights of cut depending on the weather or how difficult you want the course to play. Greenkeepers will be able to adjust the mowing patterns with the push of a button.

You will be able to upload any pattern of mowing that you want with ease.

After a while, just as we always seem to do. Nostalgia for the ways of old will come back into style and they will have to go through great effort to make mowers that create hard edges except it won't be hard. You will just push a button to present the course as it was back when they still used hickory shafts and mowers that could only cut one height of cut at a time.

We will be able to mount sensors and tools to these mowers as well.

They will drop seed and fertilizer on bare spots. They will spray weeds or kill them with lazers and target disease with UV light. This will drastically improve the environmental impact that golf courses have. No fossil fuels and highly targeted pest control using light.

Maybe this isn't realistic but the more I think of it the more excited I get about the possibilities that lie ahead.

While I really want to try out the current robot mower tech I don't think the leap from what they do today to what I have described above is that big. It would be neat to try out today's technology but we won't have to wait long for something vastly better.

This is what the mower of the future will look like. Image: husqvarna.com

More Crazy Robot Mower Ideas

Recent discussions on twitter have drummed up a lot of interesting ideas about robots and a lot of hate too!

I love it!

For the haters or skeptics think about robot mowers like this.

Do you have an irrigation system with valve-in-head rotors? Do you have a central control? If yes, your biggest piece of equipment on your course is already a robot.

Afraid robot mowers will take away jobs? How did our current irrigation system technology affect jobs of people who used to manually plug in quick coupler heads all night long? Are you willing to go back to the way it used to be with irrigation? Didn't having actual people manually plugging heads in give it that personal touch that is lost with today's "automatic" sprinkler systems? Don't you think that the precision that modern irrigation systems bring makes golf better? Don't you think that trained and skilled people are still required to operate these highly efficient marvels of irrigation technology?

Just as it is seen today to be better to spend time fine tuning the irrigation system run times instead of spending time just simply turning them on and off again, the same will be true for robot mowers.

Did anyone imaging that we would one day be able to control thousands of sprinkler heads with extreme precision with a computer we hold in our hand?

I think the same big shakeup is coming to mowers sooner than everyone thinks.

Just like with our current irrigation systems, maximum efficiency is found with many heads that distribute water over a smaller area. The same will be true for robotic mowers. Instead of having 1 or two fairway mowers like we have today, we will have hundreds of small battery powered machines.

If one of them breaks down the rest of the "swarm" will be able to pick up the slack. Today, if your only current fairway mower breaks down, nothing gets cut until it is fixed., robotic or human powered.

One big mower is expensive. Many smaller mowers will be easier to start small with and expand their usefulness in small increments. There will be no need to go all in right away. As people are hesitant to adopt the new robotic technology. This will allow them to take baby steps

We won't have mowers that are dedicated to a specific area of the course. Instead, they will have variable heights of cut and will adjust as they enter different areas of the course. Think of the robots of being like a CNC machine today. They will roam the property at times that you specify and will adjust the HOC as needed depending on their current location.

Just like irrigation systems that are designed with a specific water window in mind. We will design these mowing systems with a mowing window. The number of robots that you require will be based off of the time you wish to spend mowing each day or night.

These mowers will change golf course architecture as well. How much of our current golf course design is based off of the needs of irrigation, drainage and mower capabilities? As mower capabilities change we can only expect the course designs to change as well.

Our current mowers have rigid heights of cut. Sure we can adjust them from day to day but they cannot generally be adjusted as we mow. This leaves course areas defined by the height at which the grass is cut. Greens are the shortest, Tees and approaches are a little higher, fairways are higher yet and finally there is the rough. Some courses even have intermediate rough and naturalized areas which aren't mowed at all.

Are rigid height of cut transitions because it's what's best for the game or because it's only what is possible with our current mower technology?

With robot mowers we won't need to define areas like this. We will be able to have soft transitions from one area to another. Focusing on technology that allows robots to mow super precise borders is nice but probably not needed except for maybe the edge of greens although Chambers Bay had no defined border on their greens for years. This feature is needlessly complicated and slows the progress of these mowers. It's probably not needed.

Course architects will be able to design holes with variable heights of cut depending on the weather or how difficult you want the course to play. Greenkeepers will be able to adjust the mowing patterns with the push of a button.

You will be able to upload any pattern of mowing that you want with ease.

After a while, just as we always seem to do. Nostalgia for the ways of old will come back into style and they will have to go through great effort to make mowers that create hard edges except it won't be hard. You will just push a button to present the course as it was back when they still used hickory shafts and mowers that could only cut one height of cut at a time.

We will be able to mount sensors and tools to these mowers as well.

They will drop seed and fertilizer on bare spots. They will spray weeds or kill them with lazers and target disease with UV light. This will drastically improve the environmental impact that golf courses have. No fossil fuels and highly targeted pest control using light.

Maybe this isn't realistic but the more I think of it the more excited I get about the possibilities that lie ahead.

While I really want to try out the current robot mower tech I don't think the leap from what they do today to what I have described above is that big. It would be neat to try out today's technology but we won't have to wait long for something vastly better.

This is what the mower of the future will look like. Image: husqvarna.com

The Future of Robot Mowers Today

In my travels I am very fortunate to be able to sit in on other people's presentations. While in Denmark last month I was able to sit in on a presentation by William Boogaarts who works for de Enk Groen & Golf in the Netherlands. They have been using robot mowers for years and in my opinion are way ahead of us in North America.

Yes, I know there are a few golf courses that use robot mowers already but they are very few and far between.

In his presentation he showed the impressive self driving mower tech that has been adapted to our current mowing equipment. While impressive, this wasn't what really caught my attention. Thinking that adapting our current mowers to be self driving is completely missing the boat when it comes to robotic mowers.

He showed us how they were using the small robotic mowers from Husqvarna to mow fairways. While not 100% ideal for golf courses currently, they are relatively cheap technology that can do the job TODAY!



The more I think about using these mowers on golf courses the more they make sense and the more I think how our current equipment manufacturers might completely miss the boat and end up like Kodak. Obsolete in only a few short years.

Currently these robotic mowers can mow up to 5000m^2 on a charge which is about 1 fairway. Their HOC only goes down to 20mm which isn't quite short enough for most courses. I think this could probably be modified to cut lower.

On fairways that were mowed with this mower, experienced greenkeepers couldn't tell the difference as far as quality of cut is concerned. These mowers are relentless and will mow as often as is required during the times of day or night that you specify. They can sense where the grass is longer and will return to these areas more often and will skip areas where growth isn't as much. In the near future this data could easily be used to adjust fertilizer rates based off of growth on your course. You could also add sensors to measure moisture and even a small seeder to drop seed on bare areas.

The best part and the thing that the current greens mowing robots can't do is, they require no human interaction to do their job. You just program them and let them go. They charge themselves and mow when needed. Set it and forget it.

Because we aren't paying a person to sit on these mowers we don't need to be concerned about the speed of mowing. They can mow all the time so we can get away with much smaller machines to do the work. This small size brings a lot of benefits to the job.

They don't wear the grass out as much as big mowers. Less wear and tear is a good thing. They can travel over softer areas without sinking and leaving deep ruts. They can also mow slopes up to 45 degrees! This is a big deal for us a Pender Harbour and if the grass is wet here on our 4th hole, we can only mow downhill even with all wheel drive mowers.

This increased turf quality isn't just anecdotal. This study showed that an autonomous mower modified to mow at 1.2cm had better quality grass http://horttech.ashspublications.org/content/28/4/509

Steep slopes are a challenge for conventional mowers.

The best part I think about their small size is how they remove a lot of the mechanical complexity that the larger mowers require. No hydraulics, only 1 spinning blade. No fuel needs.

That brings up the point of transitioning to a sustainable energy use model on our courses. With large mowers their cost will only go up as the batteries are currently way too expensive for such large machines. If there's anything we don't need, is for our mowers to become more expensive. These small mowers can already be powered by battery today so the transition away from fossil fuels is easy and painless with small mowers.

There are downsides though. Because they are so small they can't mulch like our conventional mowers can. Leaves, branches pine cones and probably divots will need to be blown clear. For most of the year this isn't an issue but during the fall and winter storms this might cause issues.

Their docking stations need a power supply. If you have satellite irrigation controllers you could tie into their power supplies. If not it might be expensive to run power to each fairway.

The mowers today are only commercial or home owner specific. The leap to a golf course model is not that big. Maybe a bigger battery and a lower hoc and some sensors for moisture.

Drones will be obsolete as quickly as they became popular. There will be no need for them with these future mowers. I would not invest in drones today after seeing this. They are simply too difficult and costly to fly in some areas. Adding the sensor tech to the mowers bypasses all the issues with drone mounted tech.

Let's do some quick and dirty math to see how the return on investment might be for these mowers.

Cost of 1 current fairway mower. $60-90,000. every 5 years.

Cost to mow 10 ha of grass each season 3 times a week. $15-20,000.

Cost of fuel and mower maintenance each year. $5000+

So the cost of mowing fairways with this quick and dirty math is about $32,000 per year at best.

The robot mower with the highest capacity costs about $4500. You need 20 of these mowers to cut 10ha for a total cost of $90,000. Of course you need to supply power to your fairways but that's a one time cost and will vary a lot course to course.

So for the price of 1 fairway mower you can cut 18 holes of fairways but essentially will have no fuel cost or labor cost. You will have to spend some time cleaning debris off the fairways but that won't be significant. New blades every month or so also won't be a significant expense.

As you can see, the return on investment is about 3 years with these mowers today but you will potentially also get a better product with smaller machines. Many courses have more than 1 fairway mower so the ROI will be even quicker for them. With improvement in the tech it will be even less in short order.

It's crazy how quickly this technology is progressing. Just like other facets of the tech industry a lot of people will be caught off guard. This tech is ready today but with some tweaks it will be the best option for golf courses in every way. If you recently bought a new fairway mower, I expect it could be the last big mower you will buy. If you have an old unit that you are wanting to replace, look into this tech, the return on investment is very quick.

If this intrigues you, you can act today. These mowers are available everywhere, all they need are some forward thinking and innovative superintendents to try them out and make them work for golf.

I think I may have just purchased my last big expensive mower.

Out of Control Growth

We don’t have as much control as we think we do.

— Sean Reehoorn (@spartangrass) October 17, 2018

It's totally true. This year I had big plans to control growth on my greens and boy did I fail. Despite having an intimate understanding of how fast each and every one of my greens was growing as well as how much fertilizer I had applied and how much growth I could expect from those applications, the growth rate this past May and August went completely off the rails. You'll also notice that the previous two years I was able to achieve relatively consistent growth, then it all fell apart. WTF!

As you can see, the growth this past May and August was significantly higher than in previous years.

This despite never applying less fertilizer to the greens. The total cost this year for those that are wondering came out to $275 for 1 acre of greens or about $0.07 per square meter.

Dude!

Like Sean says, "we don't have as much control as we think we do."  Although growth this summer got away from me I have some suspicions why it might have been this way despite reintroducing growth regulators in July. The growth rates were so high that we struggled to cut enough grass each day and we were stuck with puffy conditions prone to scalping! Green speed was a challenge to maintain and we were forced to mow more than we would normally like.

Even with the elevated growth dollar spot was still a concern on a few greens. I think this is most likely due to the older bentgrass cultivars that remain on our greens. For the most part, dollar spot on the course was managed very successfully without pesticide interventions. Fairways and tees were in excellent shape all summer and didn't seem to experience the same growth explosion that the greens did.

We still have elevated organic matter from the winterkill episode of 2016. During the crazy heat we experienced this summer I bet the excess organic matter was mineralized and this led to extreme growth rates.

We started using Civitas again. Some of the product claims suggest reduced fertilizer requirements and increased growth. The first application was on the 16th of August, well into the big growth surge we were experiencing.

We started using primo again this year on July 9th and followed a strict 200 growing degree day reapplication interval helped out by my weather modeller.

As you can see, we had higher GDD this year than last so that certainly played a roll.

What else could it be?

The only other thing I can think of is grass type.

Last spring we were able to significantly increase the amount of bentgrass on our greens due to losing half of our poa thanks to winterkill.

The first green here is still mostly poa and you can see that despite it receiving higher amounts of fertilizer, it struggled to grow compared to our other bentgrass dominated greens.

It was very apparent to me this year that bentgrass grows much more with less fertilizer. Of course it could be less fertilizer or maybe the deeper rooted plant simply has access to more nutrients? There hasn't been roots deeper than 10cm for the past 20 years here so there is likely a treasure trove of nutrients in the depths below. Most plugs I sample have roots well below 20cm these days which essentially doubles the amount of nutrients available to the plant assuming it works that way.

Either way, I think the increase in clipping yield this year is partly due to having more bentgrass on the course and will allow me to potentially go even lower with fertilizer next season. Of course I will continue to monitor the growth rates and will adjust where possible despite having less control that I would like. I now also know what too much growth looks like and can really back off as we approach growth rates that can cause concern.

For more about these bitching graphs check out this post https://www.turfhacker.com/2018/03/turfgrass-maintenance-hud.html