# Cool Season Grasses best mowing height...June before summer



## KM1 (May 23, 2019)

Ok....my next noob question. What have you guys found to be the healthiest/best height to mow your cool season grass lawns. As I've mentioned, I am in a southwest suburb of Chicago....Naperville...and typically have my Honda mower set to the 2.5 setting. I assume that is 2.5 inches.

However, it does seem to be a little lighter in green color at that 2.5 setting....definitely more so than before I cut it. That is when it is at its darkest. So yesterday I set the mower to 3 and did my cut. It does look darker green at this setting. However, the next day, when I went out with an actual ruler and measure it from the top soil up...it was 3.5 inches in length. Can grass literally grow 1/2" in 24 hours???

Anyway....I am thinking of leaving it at the 3 setting but not sure if that is best. At the 2.5 setting...I need to be careful when getting to the sidewalk or curb by the street as the drop in angle of the mower can cut the edge too short. This is not as much of an issue with the setting at 3.


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## PostageStampLawnGuy (Apr 3, 2019)

I keep mine on the HRR at 3.5" here in PA


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## KM1 (May 23, 2019)

Thanks for the response.

Anyone else???

What about that growth...is it possible for grass to grow almost a 1/2 inch in a 24 hour period?


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## Jelvis (Mar 31, 2019)

I am in Palos Park, IL. At the end of the season I normally cut low (2.5 inches)before the snow comes. In the spring I normally start at 2.5 for the first month or so then gradually move up to mow at 3.5 with my Honda starting about mid May. This year with all the rain I am still mowing at 2.5 in case I have to miss a mow on account of the rain.


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## Mtsdream (May 2, 2019)

I would say if you didn't measure with a ruler right after you mowed then it may be cutting at over 3".


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## social port (Jun 19, 2017)

I like a higher cut at 4.5, but I have a stand of TTTF, and I am pretty deep in the south. My grass is typically at least somewhat greener than others in my neighborhood who cut their fescue at 4 or below. Still, I'm not totally convinced that a higher HOC leads to substantially better color.
With the mix that you have, I'd say that you are in the right ballpark between 2 and 4.

My advice is to try to strike a balance between color and disease. You may have better color with higher HOC, but you are creating better conditions for disease to take hold.

Also, I have no idea whether grass can grow 1/2 inch in 24 hours, but springtime is a time of fast growth. This spring I was cutting my fescue every 3-4 days or so, and it seemed like I still couldn't keep up with its growth.


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## Green (Dec 24, 2017)

Trying my best to maintain at 3.25 in, but not totally succeeding.


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## turfwars (Jul 4, 2018)

Hey neighbor, I'm in Naperville as well. I tried mowing tall last year (~4") and didn't care for the look as some of my turf was flopping over and I felt like I was constantly battling fungus problems. Social Port summed it up well - it's a balance between color and disease pressure. The higher cut will give you a darker color (think of a green vs fringe vs first cut of rough) but if the weather heats up soon it will be perfect conditions for disease given the abundance of rain we've had through May. I've been attempting to maintain a 2.75" HOC this year and am curious to see if the disease problems from last year come back. As for the growth rate, not sure, seems like a lot for 24hrs but could happen with favorable growing conditions and a heavy dose of N. Good luck!


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## KM1 (May 23, 2019)

turfwars said:


> Hey neighbor, I'm in Naperville as well. I tried mowing tall last year (~4") and didn't care for the look as some of my turf was flopping over and I felt like I was constantly battling fungus problems. Social Port summed it up well - it's a balance between color and disease pressure. The higher cut will give you a darker color (think of a green vs fringe vs first cut of rough) but if the weather heats up soon it will be perfect conditions for disease given the abundance of rain we've had through May. I've been attempting to maintain a 2.75" HOC this year and am curious to see if the disease problems from last year come back. As for the growth rate, not sure, seems like a lot for 24hrs but could happen with favorable growing conditions and a heavy dose of N. Good luck!


I'm not sure how to do a 2.75" as my mower doesn't have 1/4" settings. Goes from 2.5 to 3.....nothing in-between. However, I do think that the grass, when set at 3, is higher than 3" as the wheels of the mower sit on top of the thatch where the ruler, when measuring, is easily pushed through that, thus, showing a measurement longer than 3" when the mower is set at 3.

I do like the color better after I mow when set at 3, a little darker than the 2.5 setting. Not sure what will be best with all this rain. Should dry out this week a little....but then possible rain starting again Tuesday through the weekend. So where I'm at in Naperville, have had 4 straight days of NO RAIN...which has been unusual for this Spring.

If I do leave it at 3, I will have to cut it more to keep it from getting to long.....like every 3 days or so.

Not sure which I will go with....yet....hmmm.....


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## turfwars (Jul 4, 2018)

Maybe keep it at 2.5 until the weather warms a bit more and then put it up to 3 for the summer? I've been mowing a lot, every three days, but feel I could go more often with the weather. It's been a weird spring - snow in mid-April followed by the wettest May on record.


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## ken-n-nancy (Jul 25, 2017)

KM1 said:


> What about that growth...is it possible for grass to grow almost a 1/2 inch in a 24 hour period?


Yes, definitely. That's about the rate of growth I get from a northern mix during the spring growth flush -- about 3-4 inches of growth in a week is what a well-fertilized cool season grass will do with good growing conditions.


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## Chris LI (Oct 26, 2018)

KM1 said:


> Thanks for the response.
> 
> Anyone else???


It depends on your goals and what you consider "best". In the past, I've started at 2.5" and raised the HOC to 4" for peak summer, in the past.

This year, I'm holding tight at 2", as much as possible, because I love the density. Some folks are going "reel low" and staying under 1", using pgr.


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## KM1 (May 23, 2019)

turfwars said:


> Hey neighbor, I'm in Naperville as well. I tried mowing tall last year (~4") and didn't care for the look as some of my turf was flopping over and I felt like I was constantly battling fungus problems. Social Port summed it up well - it's a balance between color and disease pressure. The higher cut will give you a darker color (think of a green vs fringe vs first cut of rough) but if the weather heats up soon it will be perfect conditions for disease given the abundance of rain we've had through May. I've been attempting to maintain a 2.75" HOC this year and am curious to see if the disease problems from last year come back. As for the growth rate, not sure, seems like a lot for 24hrs but could happen with favorable growing conditions and a heavy dose of N. Good luck!


Hey Turfwars,

We have had no rain now for like, what, 4 or 5 days....are you planning on watering this week at all....or wait to see if it does rain this week before?

I know it is SUPPOSED to rain again Tuesday....but you know how that goes around here. In fact, they are predicting up to 70% rain possible Tuesday night, and then no rain again until Friday and Saturday. Just wondering with all the rain we have had.....how long to let it dry out until the grass needs more water.

Just thought I'd ask!!!


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## turfwars (Jul 4, 2018)

No, nothing planned just yet. I'm sure my roots are really lazy right now and could use a little stress to help drive them down. I'll monitor to see if it really starts to struggle but I'm hoping the rain will naturally water in my grub preventer to avoid using the sprinklers this week.


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## KM1 (May 23, 2019)

Yea....I put on my grub preventer like 2 days before that TORENTIAL downpour we had. I mean I had a river running down my sidewalk there was so much rain. AND 1 day after I put my fungicide on.

I'm hoping it didn't wash it all away and I'm left with NO PREVENTION!!!


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