# Cool Season Lawn - Question on brown grass blades



## bodean (Aug 21, 2020)

Live in zone 
My lawn is 3 years old, the front was sod (not sure on the grass type though) on top of a layer of topsoil which is on top of clay. I've noticed since I started maintaining the yard on my own (opposed to a service) that there are brown grass blades scattered throughout my front lawn. I noticed this during the summer last year, as well as now in early spring. Any explanations to this? I'm striving for the deep green lawn that everyone strives for, and wondering if this is just the type of grass, or sign of disease, or what the explanation is. If there is something I can do to correct this, would rather address it head on in the beginning of the growing season now then wait until summer.

I threw down a 12-12-12 fert about 2 weeks ago, and put down some milogranite yesterday thinking maybe the little extra Nitrogen would push the growth faster to get these blades out, but doesn't explain why I still see them in the summer months also. Soil temps around the Chicago area have been 48-55F over the last few weeks also. 
Maybe this is normal with the type of grass I have...... that's why I am asking the pros on here :thumbup:


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## Girls4green-beginner (Sep 21, 2020)

You need to thatch


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## bodean (Aug 21, 2020)

Girls4green-beginner said:


> You need to thatch


My neighbor has a power rake / dethatcher. Ill ask to borrow it. Is it too early in the season to do it? I've read that it should be done in the fall for cool season, and not to fertilize the lawn for at least 45 days prior to dethatching. Because I fertilized recently I am thinking detaching the lawn now would interfere with the fert applications and I will have to reapply? I just have noted that the lawn was Aerated in the Fall.


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## Girls4green-beginner (Sep 21, 2020)

No you need to get thatch up so fertilizer can contact soil and not rotting grass. I've thatched after fertilizer and it just drops down.


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## davegravy (Jul 25, 2019)

Girls4green-beginner said:


> You need to thatch


I've heard a few people have issues with running the power rake too early during spring greenup and really stunting their grass. Make sure things are growing very well before attempting this. Also be aware the difference between thatch and lawn debris which is often misunderstood. Make sure you know which problem you have.

Matted down dead grass is the latter and doesn't need as deep a power raking. Thatch is at root level, it's a rootball. Requires a deeper raking /scarifier. Warning: deep intrusions into your soil risks breaking your pre emergent barrier.


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## bodean (Aug 21, 2020)

davegravy said:


> Girls4green-beginner said:
> 
> 
> > You need to thatch
> ...


Forgot about the pre emergent barrier (put that down 2 weeks ago. So I guess I either do nothing, or use the green works 14" DETHATCHER I have on its lowest setting and dethatch and reapply everything again, or maybe not use the lowest setting and use it to take up the dead/matted grass? I did a gentle raking by hand a few weeks ago.


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## moedank (Sep 10, 2019)

Looks like fescue mixed in with some left over winter dormant/dead grass blades. Not technically thatch. I did a light "dethatching" on a couple of light brown areas in my fescue yard, which have greened up well over a two week period. Used a Sun Joe dethatcher on the highest from the ground setting, which still may have been overkill. Light or moderate raking should suffice. You could also cut the grass a little shorter than usual once or twice while it's still early in the spring to help remove it.

I wouldn't apply anymore fertilizer. How much did you put down lb/ksqft?


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## bodean (Aug 21, 2020)

moedank said:


> I wouldn't apply anymore fertilizer. How much did you put down lb/ksqft?


3lb/1000sqft


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## g-man (Jun 15, 2017)

Girls4green-beginner said:


> No you need to get thatch up so fertilizer can contact soil and not rotting grass. I've thatched after fertilizer and it just drops down.


Fertilizer will get to the soil once you water it in. This lawn just needs to be mowed and wait for warmer temps.


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## bodean (Aug 21, 2020)

g-man said:


> Fertilizer will get to the soil once you water it in. This lawn just needs to be mowed and wait for warmer temps.


Thanks. Mowed last week at 2 3/4" and bagged. Then mowed at 3 1/4" and mulched yesterday. Will wait for warmer temps


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## davegravy (Jul 25, 2019)

bodean said:


> davegravy said:
> 
> 
> > Girls4green-beginner said:
> ...


Really depends if you actually have a thatch problem. Does the turf feel very spongy when you walk on it? I would dig up a few plugs of turf and try to measure the thatch layer. IIRC up to about 3/4" deep is fine. Beyond that you might consider dethatching.


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## bodean (Aug 21, 2020)

So I am back with a dilemma. Overall my lawn is fairly green, but when you get close to it, there is some browning. I managed to buy a soil probe, and pull a plug out to see what was going on. As some in this thread mentioned, thatch. Should have been more proactive a month ago.....live and learn right? The odd thing is, my lawn is 3 years old, and each fall, I aerate the yard (which I thought would prevent this thatch).

So my dilemma is this. We are now mid may. Yesterday I put down my 2nd application of Prodiamine at 3lb/1000sqft (6000 sq ft lawn). I also applied RGS, GrubEX and Yard Mastery Flagship 24-0-6 this past Tuesday. 
I guess I have 3 options moving forward. 1) Do nothing with the thatch, 2) Spray some N-ext D-Thatch down (temps will be in the high 60's to mid 70's the next 7 days) or 3) Go rent a Power Rake at HD and take care of it.

If I go route 3, what will happen to my prior applications in the soil? I assume the Prodiamine that I put down yesterday will be ruined, but other than that, will the rest of the fertilizers and sprays be safe in the soil to do their jobs? Anyone have any experience with N-ext D-Thatch? Might not tear up the lawn as much going that route.


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## g-man (Jun 15, 2017)

How often are you watering?


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## bodean (Aug 21, 2020)

g-man said:


> How often are you watering?


Seeing how we got some rain the last few weeks, my Rachio 3 ran maybe 7 times since April 1st. It's set on a flex daily / deep watering schedule


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## g-man (Jun 15, 2017)

Check the settings. The shallow roots in the image could be from too frequent irrigation. Check the root depth and nozzle precipitation rate.


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## bodean (Aug 21, 2020)

g-man said:


> Check the settings. The shallow roots in the image could be from too frequent irrigation. Check the root depth and nozzle precipitation rate.


According to Rachio app, root depth for that zone is 5.9in (which I believe is default for clay soil setting) and nozzle inches per hour is 1 in (did the tuna can test last year to calibrate all the heads). I don't think its getting close to "too frequent" irrigation as I haven't run the sprinklers much at all. I have put down RGS / Air8 twice this spring to aid in root depth.

Is the best course of action to cut to a 2inch height, run a power rake out there, put down another application of 24-0-6 fert and let it recover? Or wait it out until June when it's hot and put down some liquid D-Thatch down to burn it off?


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## bernstem (Jan 16, 2018)

I would mechanically dethatch that lawn. It will cause some damage/thinning, but the lawn should bounce back healthier. If you don't want to mechanically dethatch, you can try the N-Ext D-thatcher, but it may take more time than you want to make a difference. A mechanical power raking will remove the thatch immediately and a bit of Nitrogen will help it recover.


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## bodean (Aug 21, 2020)

bernstem said:


> I would mechanically dethatch that lawn. It will cause some damage/thinning, but the lawn should bounce back healthier. If you don't want to mechanically dethatch, you can try the N-Ext D-thatcher, but it may take more time than you want to make a difference. A mechanical power raking will remove the thatch immediately and a bit of Nitrogen will help it recover.


Thanks
I'll run a sun joe over lawn. As for nitrogen, what do I recommend? Would I be wasting my flagship fert if I put it down again (put it down last week)


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## bernstem (Jan 16, 2018)

bodean said:


> bernstem said:
> 
> 
> > I would mechanically dethatch that lawn. It will cause some damage/thinning, but the lawn should bounce back healthier. If you don't want to mechanically dethatch, you can try the N-Ext D-thatcher, but it may take more time than you want to make a difference. A mechanical power raking will remove the thatch immediately and a bit of Nitrogen will help it recover.
> ...


I have never used one, but I think a sun joe may take a few passes to get up a thick layer of thatch.

If you just applied nitrogen last week, you don't need any more right now. Dethatch and wait. If it is not bouncing back by 2 weeks from the dethatching, consider a small dose of Nitrogen (0.25-0.5 lbs N/1000).


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## Nikegolf1224 (Apr 21, 2021)

What are the ingredients to Next de thatch? What things could help aid the breakdown of thatch? Molasses?


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## g-man (Jun 15, 2017)

I think it is more important to figure out how the lawn ended up like this. That way you can prevent it. It looks like most of the roots are in the first 1in.


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## bodean (Aug 21, 2020)

g-man said:


> I think it is more important to figure out how the lawn ended up like this. That way you can prevent it. It looks like most of the roots are in the first 1in.


The lawn is 3 years old. I'll keep an eye the next few weeks on root depth to see if it improves now that I did 2 passes with the Sun joe. I don't think water is an issue as again my Rachio is connected to my OWS and does a good job monitoring rain and when it needs water. I could bump the 5.9 inch root depth on Rachio down to maybe 3 or 4" and see what happens

@bernstem Bought a sun joe. Cut my lawn down to 2". Put the scarifying attachment on, position 4 (-5 mm) and made 2 passes in opposite direction. Filled up 10 bags. Hopefully this helps…. Did not use the detach rake attachment as it doesn't go deep.


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## g-man (Jun 15, 2017)

If you bump it down (3in), it will water more frequently. Keep it at 6in. You used the Rachel in the last 3 yrs?


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## bodean (Aug 21, 2020)

g-man said:


> If you bump it down (3in), it will water more frequently. Keep it at 6in. You used the Rachel in the last 3 yrs?


Been using the Rachio 3 years, yes


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## g-man (Jun 15, 2017)

Also, take a core sample now after running the sunjoe to see the change.


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## bodean (Aug 21, 2020)

g-man said:


> Also, take a core sample now after running the sunjoe to see the change.


3 separate locations on the front lawn, post dethatch. Like I mentioned it picked up a lot of dead grass / thatch (10 bags, 5800sqft yard)


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## g-man (Jun 15, 2017)

Hmm, i think it might need more.


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## bodean (Aug 21, 2020)

g-man said:


> Hmm, i think it might need more.


Ya, I don't know. Suppose to rain most of the week. Could run another pass on the -5mm setting, or go deeper on the -10mm setting, or just wait until next month and put down the N-ext D-Thatch.


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## creediddy2021 (Mar 27, 2021)

Great recommendations G-man. I was thinking of the same thing in terms of his water schedule/intervals. Based on the pics the grass looks like it could benefit from additinal watering. I live in Chicagoland area as well, but our rainfall over the last 5-7 days have been less than .5". So additional watering is necessary.


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## bodean (Aug 21, 2020)

g-man said:


> Hmm, i think it might need more.


I set the Sun Joe to the deepest setting ( -10mm) Filled up another 3 bags. I also changed the Rachio from flex daily to a flex monthly schedule, and sprayed some Hydratain on my lawn. Hopefully this fixes the issues I was having.


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## g-man (Jun 15, 2017)

I use the flex on mine and don't have that problem. It waters around 0.5in every 3 days in the peak of summer


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## bodean (Aug 21, 2020)

g-man said:


> I use the flex on mine and don't have that problem. It waters around 0.5in every 3 days in the peak of summer


Flex daily or flex monthly? 2 different ways to use the unit. I assume you went out and measured the roots? Or did you leave the advanced stuff default based on your soil type? (I have clay soil).


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## g-man (Jun 15, 2017)

Flex daily. I did measure the roots and did multiple catch cups. I designed my irrigation system to be fairly even.

You likely have silty clay instead of pure clay. It is just a minor difference.


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