# Orange / Yellow / Brown Lawn Spots



## Lawndad (May 23, 2017)

Hey everyone - I have been looking for an answer to this question since last season and I still haven't figured out the cause. I have been experiencing this orange/yellow/brown grass in my lawn. I want to say it's spread pretty evenly in my lawn but not in too much in my front yard. The front receives the most sun and I don't have any trees near me but my entire lawn gets sun as it makes its way around the house.

I inquired with "the other forum" and really didn't get too much of a solution and I even went to the extreme of sending in a tissue sample to Rutgers Lab. I'll attach their findings as well as my soil sample, applications I made this season and some pics. The soil test was before any applications this season and the tissue sample was in April. I still have't gotten rid of this as the scientist thought it would "grow out". He said I was doing way too much and don't really need fungicide and much fertilizer. He was from the camp to just do a few fert. applications a season and let it go. He indicated it was old disease from last year but I'm noticing more this year. I am just looking for other opinions. Just to mention a few things, I sharpen the mower blades every few cuts this season and I try to water 1/2" twice a week but when I get stress spots I have to water more. In my applications, I sometimes use the # to note the setting on my spreader not pounds.

Thanks for any input. -LD


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## Virginiagal (Apr 24, 2017)

I agree with the Rutger's scientist. You are doing way too much fertilizer. Fescue is vulnerable to brown patch and it will happen every year when conditions are conducive for it to develop. The fungi come out from the soil and attack the leaves. It does not affect the crown or roots so the grass can grow back. It has been very stressed, though. Enough stress and it won't come back. It looks like you do not have a devastating brown patch attack. You have live grass! Be grateful it's not worse. Here are things you can do to lessen the severity of brown patch;
1. Do not fertilize in the spring unless necessary (chloritic grass, very slow growth) and then only 0.25- 0.5 lb/k nitrogen. Fertilize with 2-3 lb/k nitrogen in the fall. Do not fertilize in the summer. That includes Milorganite.
2. Water as infrequently as possible. Wait until the grass shows signs of needing water. Water very early in the morning, never in the afternoon or early evening. You need to keep the grass blades as dry as possible as long as possible.
3. Cut at 3 inches when it's warm/hot and humid. You want a long enough grass blade to have good photosynthesis. But grass cut too high (like 4 inches) trap a lot of humidity and that humidity is the thing the fungi like. If you are cutting higher, gradually lower the cut. Even lowering to 3.5 from 4 can make a difference.
4. Research cultivars that have good brown patch resistance. Use them when you overseed in the fall.


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## g-man (Jun 15, 2017)

"Sometimes less is more" - Rutger Scientist


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## Lawndad (May 23, 2017)

Thank you guys, I will start to follow those tips.

I do try to water that way when I can and I cut at 3.5". I recall hearing the Milorganite won't contribute to fungus based on the make up of the nitrogen but I don't know though. Here is the strange part that I am trying to figure out. I have a friend that fertilizes twice as much as me with twice as much fungicide. His grass (same grass) is greener with none of this. I said I'd like to see how your lawn does this summer with disease vs. mine. So far his is deeper green with no orange/yellow blades and it was similar last year.

The Rutgers scientist that I spoke with said that sometimes even if you follow the textbook on what and when it won't get you the results you need. :?


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## Virginiagal (Apr 24, 2017)

Organic nitrogen must be converted to inorganic forms (ammonium and nitrate) before it can be used by the plant. Microorganisms perform this task. The advantage is less chance of leaching and a slow release of nutrients. The nitrogen forms that the plant uses are the same as provided in synthetic fertilizer.

Here is some information from my notes of Robert Carrow's Turfgrass Soil Fertility and Chemical Problems about nitrogen. When N is very high, there can be a decline in number of tillers and density, partly due to shading, inadequate mowing frequency, and limited carbohydrates. Above medium N there is a rapid loss of carbohydrate reserves in cool season grass with addition of more N. Warm season grass is less suspectible but there is a possibility of depletion of reserves if N is consistently applied at high rates. Drought resistance is highest at medium to low N. Tolerance to stress drops at high N. Grass is more susceptible to wilting as N increases. From low to medium N the tendency is for no further thatch. At high N thatch levels increase. When turf density is lost to weed competition, pests, or traffic, additional N is needed to improve density. Adequate water needed too. If N is too low, weeds may predominate. Higher N tends to enhance poa annua at the expense of other cool season grasses, especially when applied in the spring. Under high N there are thinner cell walls, more succulent tissue, low carbohydrate levels, and grass is more susceptible to pythium and brown patch. Low N results in slow growth, senescence of leaves, thin weak plants which are more susceptible to dollar spot, rust, red thread, and pink patch.

Summing up: you need adequate nitrogen but too much is a problem.


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## Lawndad (May 23, 2017)

Virginiagal said:


> Organic nitrogen must be converted to inorganic forms (ammonium and nitrate) before it can be used by the plant. Microorganisms perform this task. The advantage is less chance of leaching and a slow release of nutrients. The nitrogen forms that the plant uses are the same as provided in synthetic fertilizer.
> 
> Here is some information from my notes of Robert Carrow's Turfgrass Soil Fertility and Chemical Problems about nitrogen. When N is very high, there can be a decline in number of tillers and density, partly due to shading, inadequate mowing frequency, and limited carbohydrates. Above medium N there is a rapid loss of carbohydrate reserves in cool season grass with addition of more N. Warm season grass is less suspectible but there is a possibility of depletion of reserves if N is consistently applied at high rates. Drought resistance is highest at medium to low N. Tolerance to stress drops at high N. Grass is more susceptible to wilting as N increases. From low to medium N the tendency is for no further thatch. At high N thatch levels increase. When turf density is lost to weed competition, pests, or traffic, additional N is needed to improve density. Adequate water needed too. If N is too low, weeds may predominate. Higher N tends to enhance poa annua at the expense of other cool season grasses, especially when applied in the spring. Under high N there are thinner cell walls, more succulent tissue, low carbohydrate levels, and grass is more susceptible to pythium and brown patch. Low N results in slow growth, senescence of leaves, thin weak plants which are more susceptible to dollar spot, rust, red thread, and pink patch.
> 
> Summing up: you need adequate nitrogen but too much is a problem.


Yes, you summed it up pretty much. You have to keep it at that happy medium spot.

I see the same grass that my HOA takes care of and you know their programs are the bare basic. I see the same yellow grass in there too.

Then you have mine with a higher nitrogen content with it.

Then I have another guy who does more than me without much of it.

So those things are what makes all of this odd and all of the grass is cut from the same sod farm.

Who knows what is that happy medium exactly is...


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## Virginiagal (Apr 24, 2017)

It may be luck of the draw as far as brown patch. The fungus that causes it, rhizoctonia solani, is in the soil. Some soil may have it, some may not. Your friend without brown patch seems to do a lot of fungicide. That is probably why he doesn't have it.


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## Lawndad (May 23, 2017)

Virginiagal said:


> It may be luck of the draw as far as brown patch. The fungus that causes it, rhizoctonia solani, is in the soil. Some soil may have it, some may not. Your friend without brown patch seems to do a lot of fungicide. That is probably why he doesn't have it.


Yeah I guess that makes sense. I'm going to drop more fungicide then! :thumbup:


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