# Yellow-green zoysiagrass blades



## Movingshrub (Jun 12, 2017)

This came up in a different thread and I didn't want to hijack that persons thread, and this was more than I wanted to PM.

@Greendoc

Below are photos of the highlighter green zoysia blades. This occurred last year and I'll put all the information I have below the photos in the event this happens to someone else. I am still unsure what caused the issue but my assumption is excess nitrogen. Due to the constant application of water for the sprigs, I kept the area from getting burned. Note, the sprigs were Bermuda and did fine.

Also, there is a granular pre-emergent with a strong mothball smell that was applied in this area, that I wouldn't *think* to cause phototoxicity since the label notes it's compatable with sprigging. However, I know that the sprayable versions can cause discoloration to established turf, so there's always that possibility as well.

I have no clue what type of zoysia it is.













For 2017 -
I have been applying one pound of nitrogen 
(ammonium sulfate & urea blend) per thousand square feet, to the whole yard, since June 15th and stopped on Sep 9th. For every three weeks of just nitrogen, the fourth week I applied an all purpose 15-15-15 fertilizer, also at the rate of 1lb of N per 1k sqft.

Regarding herbicides, I applied a split application of granular dithopyr in February and in May(excluding the areas to be sprigged), I used Celsius WG, I hand brushed glyphosate on crabgrass, and used a mixture of triclopyr and 2,4-D ester, like an amateur in early May, making the yard look like a spotted leopard.

On August 29th I applied a spray application of a product containing chelated iron and other micronutrients (Copper - 0.05% Iron - 3.25% Soluble Manganese - 0.15% Zinc - 0.16%), with no visible improvement since application.


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## Greendoc (Mar 24, 2018)

First of all, the type of Zoysia is Japonica. Matrella types have much finer leaves. The highlighter yellow could have multiple causes, but if it is patchy like that, I tend to blame nematodes. Normally, Zoysia japonica is extremely resistant to both herbicides and fertilizer overapplication. That is why it is used in Hawaii, "landscapers" cannot kill it. However it is very susceptible to nematodes. They damage the root system in such a way that fertilizers and micronutrients do not produce a positive response. The nematode damage to the roots also causes the grass to lose all resistance to diseases such as Pythium and Rhizoctonia Large Patch. I found this out over the last 10 years because as of 2000, just about every single lawn in Hawaii was replaced with Zoysia japonica billed as disease resistant when the TifDwarf and Tifgreen lawns all died from Take All Patch during the 1990s. Those supposedly disease resistant Zoysia lawns have been struck by nematodes followed by Pythium and Large Patch.

When Zoysia Japonica looks yellow and patchy in spite of being watered and generously fertilized, I apply this.










Officially, it is labeled for Dollar Spot, Snow Mold, and Large Patch. However, one of the fungicides contained is actually extremely active against nematodes. I have had lawns previously treated with the likes of Insignia, Prostar, Armada, 3336, and Eagle turn back to green in a matter of weeks.

This stuff is not cheap by any means. However the Fluopyram product officially labeled for nematodes is $100 per ounce.


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## TulsaFan (May 1, 2017)

I have been asking @Greendoc some questions about Exteris Stressgard in a private message.

Regarding application rate, he stated: "I apply Exteris at 4 oz per 1000 sq ft 3 times in a year. Spring, Summer, then one more time in Fall. No need to apply other fungicides for Large Patch if on this program because Exteris takes care of that problem as well."

Siteone sells it for $275 for 2.5 gallons. Seems expensive, but it will break down to $14.47/year for the amount of zoysia in my yard.


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## BenC (Mar 27, 2018)

That's great info. Love learning new stuff&#128077;


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## BenC (Mar 27, 2018)

Do you turf guys do tissue analysis ever?


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## Ware (Jan 28, 2017)

BenC said:


> Do you turf guys do tissue analysis ever?


Probably not often enough. I hear it's the best way to determine things like micronutrient deficiencies. What can you tell us about it? Who does it, what does it cost, etc?


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## Greendoc (Mar 24, 2018)

Most labs that do soil for golf and AG will do tissue tests as well. I do not chase numbers though. I use soil tests as a baseline and adjust my programs for green grass without excessive growth. Unless I am doing a grow in or fixing a starved and stripped lawn, my N levels are moderate, but the micronutrients are emphasized. I think agronomists talk out of both sides of their mouth when they state that grass is ok at a soil pH over 7. I will show you grass that needs a lot of micronutrients and utilizes N and P less efficiently than grass growing on soil pH 6.5.


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## BenC (Mar 27, 2018)

Soils can be complicated and sometimes issues aren't caught there. Like @Greendoc said, there are disputes about simple things like pH, there's just a lot of variables that compound the complexity. A high pH, calcareous soil might produce fine, while a high pH elluviated soil might be inadequate for prime production. At the end of the day the only thing that matters is what is getting into the plant. Soil testing is an indirect measurement of what we're trying to accomplish. Tissue testing is a direct measurement of plant health. Both are vital measurements.


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## Movingshrub (Jun 12, 2017)

What situations would call for tissue testing?


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## Greendoc (Mar 24, 2018)

Movingshrub said:


> What situations would call for tissue testing?


When soil pH is optimal, the fertilizer program is on point, irrigation is on point, and there are no nematodes or fungal diseases that could explain the off color turf. Tissue testing is utilized a lot when turf is being kept on the edge of starvation. For those of use not going down that rabbit hole, soil testing to get a base line and applying a balanced. complete fertilizer including micronutrients is what is needed for green grass. I know the difference between grass that is well fertilized and not. Then again, I am dealing with a variety of Zoysia that wants to grow 4" in one week fertilizer or not at this time of the year provided it has sufficient water. The Zoysia lawn that is not under attack by nematodes or Large Patch normally needs to be on the max rate of PGR to be maintainable on a 7-10 day mowing. If people are willing to accept less than Astroturf green grass, I can normally manage growth by restriction of water. Never over irrigate El Toro or Zeon when daytime temperatures are over 80 unless you are prepared to do a lot of mowing or you can apply growth regulators. I believe your type of Zoysia is probably a wild seeded variety of Zoysia japonica, which is similar to El Toro or Empire or Jamur.


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## jpbutler (Aug 19, 2020)

It looks like I am having the same issue with highlighter green grass in my zoysia this spring. Can anyone confirm if this is nematodes? And is the best way to get rid of them Exteris Stressgard Fungicide?

I am located in North Alabama.

@Greendoc


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## Tmank87 (Feb 13, 2019)

Would be interested in the best place to buy


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## jpbutler (Aug 19, 2020)

Tmank87 said:


> Would be interested in the best place to buy


It can be bought here: https://www.reinders.com/products/8405771/

I just want to make sure this is the problem I have and that this will fix the issue before I spend this kind of money.


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## Tmank87 (Feb 13, 2019)

jpbutler said:


> Tmank87 said:
> 
> 
> > Would be interested in the best place to buy
> ...


Thanks. I saw they offered it but didn't know if anyone knew the best pricing.

Completely understand wanting to diagnose. Im interested from a brown patch/fungicide perspective. Nematode control is just a bonus for me.


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## Rammy1546 (Jan 3, 2020)

@jpbutler I am having the same issue down here in Birmingham. Can't figure out what the issue is.


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## Rammy1546 (Jan 3, 2020)

Bringing this one back to the top:

Any other ideas why the zoysia is turning lime green? Grass looked great 10 days ago. Still coming out of dormancy a bit.

Do you guys recommend a soil test? I have only applied .25lb/1000 sq ft Scott's bonus s and sprayed Propicanozole 2oz/1000sq ft this spring.

You think just chill out until May and full green up and let it grow out? Trying to be proactive since I was hit with Brown Patch in fall and still recovering.


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## Vatintman1 (May 26, 2021)

You need to remove the excess material from last growing season if your not doing so. Scalp it early in the year and collect bag it.

Is yours growing in a lot of shade? If so Zzoysia wont perform as well, yes Zoysia is ok with shade but the more sunlight the better. Im having the same issue but mine is in full sun.


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## Vatintman1 (May 26, 2021)

I have redone the edging so I have sodded in some places where cool season grass was hanging on or the damn Bermuda was winning over the zoysia. I havent cut this piece because I noticed the yellow so I wanted to see what would happen.


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