# Yellowing St Augustine



## Ktungsten (Aug 27, 2019)

Hey guys. For the last month, my SA has been yellowing in certain spots. The areas appear to be growing in size and popping up around the yard. I can't find any insect damage, the roots are strong, and the leaf blades don't have lesions on them. I put peat moss out last weekend and again yesterday in case it was a fungus. Thoughts on what might be causing this?


----------



## mjh648 (Sep 1, 2020)

Could be iron chlorosis. Have you gotten a soil test recently? Could try some ironite. I was considering starting my preventative fungicides around mid April with a dose of Azoxystrobin.


----------



## SCGrassMan (Dec 17, 2017)

Could be take all patch or grubs


----------



## Darth_V8r (Jul 18, 2019)

Google "lethal viral necrosis st augustine". It looks an awful lot like the pics you posted. I hope I'm wrong...


----------



## mjh648 (Sep 1, 2020)

Darth_V8r said:


> Google "lethal viral necrosis st augustine". It looks an awful lot like the pics you posted. I hope I'm wrong...


well that escalated. You think this Florida based disease has found it's way to rural Texas?


----------



## Redtwin (Feb 9, 2019)

Let's start simple first... Do you have any pets back there? If not, get down and dig around a little or do the coffee can test to see if you have any insect issues.


----------



## Symbiont01 (Nov 20, 2018)

The alternating green and yellow stripes on the blades have me thinking its chlorosis as well. Being in Boerne, this would be consistent with high pH soils of our area making iron less soluble and rendering it unavailable to the plant. Treatment would be a foliar chelated iron spray in the short term. Long term is trying to get your soil pH down using applications of granular sulfur and liquid citric acid so that any iron in the soil is plant available (this will take patience and time in Central Texas with all the calcium/ limestone in our soils).

Some people make their own chelated iron by mixing ferrous sulfate with citric acid (2 oz FS with 4 oz citric acid/ 1000 sq ft), but you can buy it already chelated


----------



## Spammage (Apr 30, 2017)

@Ktungsten voting chlorosis. I've get a few areas that sometimes break dormancy the same way.


----------



## SCGrassMan (Dec 17, 2017)

https://soilsalive.com/resources/organic-advice/is-take-all-root-rot-killing-your-lawn/


----------



## Ktungsten (Aug 27, 2019)

Going to put out some chelated iron. That's kinda the direction I was leaning. Just ordered some more Main Event iron since I used up all of mine last year. I've checked the grass and don't see any insect or fungal damage. Appreciate everyone's input.


----------



## Ktungsten (Aug 27, 2019)

SCGrassMan said:


> https://soilsalive.com/resources/organic-advice/is-take-all-root-rot-killing-your-lawn/


That's concerning since the article mentions that the leaf blades don't pull away from the stolons. That's what I'm seeing now. I'll spray some of the fungicides I've got as well.


----------



## mjh648 (Sep 1, 2020)

@Ktungsten is your soil compacted, have you been watering a lot and do you see any nutsedge? Found this in my newly sodded area tonight and put out some Azoxy @ 2#/K to see if it fixes it. I check all the boxes of those conditions above.

Could be something else but a preventative rate of Azoxy wouldn't hurt it.

Interesting article about take all patch if you want to read about it.

https://www.natureswayresources.com/DocsPdfs/brownpatch.pdf


----------



## cldrunner (May 14, 2019)

@Ktungsten Are the roots dark? Can you pull them easily? My guess is Take all Patch/ Take all Root Rot.

https://www.greencastonline.com/tools/pestoutlooks.aspx

https://agrilifeextension.tamu.edu/library/landscaping/take-all-root-rot/


----------



## CenlaLowell (Apr 21, 2017)

Man I get this every year and I have it right now as well. Have no idea what it is but it doesn't effect the grass. It's not an insect problem because I sprayed two insecticide last month one good for 90 days and the other 6 months. I think it's an iron deficiency and I'm not doing anything about it either.

I worry about GLS!!!!


----------



## mjh648 (Sep 1, 2020)

CenlaLowell said:


> I worry about GLS!!!!


That no fert program should help.


----------



## CenlaLowell (Apr 21, 2017)

mjh648 said:


> CenlaLowell said:
> 
> 
> > I worry about GLS!!!!
> ...


I hope so


----------



## Ktungsten (Aug 27, 2019)

mjh648 said:


> @Ktungsten is your soil compacted, have you been watering a lot and do you see any nutsedge? Found this in my newly sodded area tonight and put out some Azoxy @ 2#/K to see if it fixes it. I check all the boxes of those conditions above.
> 
> Could be something else but a preventative rate of Azoxy wouldn't hurt it.
> 
> ...


I did have compacted soil but it's gotten a lot better as of now. Haven't watered that much at all and don't have very many nutsedge since I sprayed a few times 3Q-4Q last year. I'll spray iron tomorrow and likely wait on the fungicide until Sunday.


----------



## Ktungsten (Aug 27, 2019)

CenlaLowell said:


> Man I get this every year and I have it right now as well. Have no idea what it is but it doesn't effect the grass. It's not an insect problem because I sprayed two insecticide last month one good for 90 days and the other 6 months. I think it's an iron deficiency and I'm not doing anything about it either.
> 
> I worry about GLS!!!!


It's strange because the grass otherwise appears healthy. Doesn't pull up easily, doesn't have lesions, and no insects I can find.


----------



## ionicatoms (Mar 8, 2020)

I observed yellowing in my St. Augustine grass over the second half of last year. I treated with micronutrients available in the palm nutritional product. The yellowing has disappeared since the grass came out of dormancy.

I'm not sure if the nutrients resolved the problem or if the grass needed time to recover from some other stress, such as herbicide or insecticide or fungicide.

All "Before" shots are from September.

Top: After (the yellow spots are actually just where the light shines through my tree, Maybe I can get a better photo later). 
Bottom: actual yellow discoloration



Left: After
Right: Before



Close ups:





cc:@UltimateLawn


----------



## CenlaLowell (Apr 21, 2017)

ionicatoms said:


> I observed yellowing in my St. Augustine grass over the second half of last year. I treated with micronutrients available in the palm nutritional product. The yellowing has disappeared since the grass came out of dormancy.
> 
> I'm not sure if the nutrients resolved the problem or if the grass needed time to recover from some other stress, such as herbicide or insecticide or fungicide.
> 
> ...


Iron deficiency more than likely I get it every year though and even when I spray it would even turn back to the line color over time.


----------



## Ktungsten (Aug 27, 2019)

Wanted to close the loop on this post in case others have the same issue. Grass seems to be recovering. I added peat moss, alfalfa, then iron a week later.


----------



## UltimateLawn (Sep 25, 2020)

I decided to drop some Azoxystrobin and Clearys this evening to shock any fungus there may be. I'll keep an eye on things, but my growth is definitely stunted and the yellow patches are pretty much randomly everywhere. I think it is a mild case of take all root rot.

If things improve, I'm going to do a nitrogen drop after the yellowing comes to a close.

I really need to start a monthly fungus prevention program. If these fix the issue, then I will know what it likely is.


----------



## ionicatoms (Mar 8, 2020)

I've got some yellowing in the backyard that I can try out fungicide on too. I'll let you know.


----------



## CenlaLowell (Apr 21, 2017)

UltimateLawn said:


> I decided to drop some Azoxystrobin and Clearys this evening to shock any fungus there may be. I'll keep an eye on things, but my growth is definitely stunted and the yellow patches are pretty much randomly everywhere. I think it is a mild case of take all root rot.
> 
> If things improve, I'm going to do a nitrogen drop after the yellowing comes to a close.
> 
> I really need to start a monthly fungus prevention program. If these fix the issue, then I will know what it likely is.


What makes you think it's take all root rot?? I realize that yellowing is a part of take all but here it says root turn black


I'll go pull and look at my roots to make sure though.


----------



## UltimateLawn (Sep 25, 2020)

I have roots that appear to be that in several spots losing turf and the yellowing is increasing thus far. I do need to check the roots, but it is time for a regular fungicide app here given the constant high to cool temperatures. My lawn has struggled with a number of fungus species in the last year when I said goodbye to my previous lawn service.

I have spots that have no StAug with exposed roots and yellowing borders. Some pics...

That being said, I will check the roots again. Last time I checked the yellowing blades were 'freshly affected' and they seemed to have roots (still), but they were neighboring some already damaged sections. Just hoping for the best.


----------



## mjh648 (Sep 1, 2020)

I wouldn't think it's a fungus if it's localized by the concrete. Have you ruled out cinch bugs and/or water coverage by the hot concrete?


----------



## UltimateLawn (Sep 25, 2020)

Water coverage has been good. Bermuda has been going crazy there!

I have not done any Cinch bug testing yet. Will do so later today.

Also yellowing spots are not just by the curb.


----------



## Awebster54 (Jun 15, 2019)

I was dealing with what I am pretty sure was Take all root rot. I put some peat moss down and it seems to have responded nicely. Not sure if it ultimately fixed yours but it seemed to help both of us.


----------



## UltimateLawn (Sep 25, 2020)

Yellowing had not improved, so I dropped down some peat moss today on the areas most yellow. We will see how things go from here.


----------



## TJ_FortWorth (Apr 23, 2021)

UltimateLawn said:


> Yellowing had not improved, so I dropped down some peat moss today on the areas most yellow. We will see how things go from here.


Keep us updated! I am in the same boat.


----------



## UltimateLawn (Sep 25, 2020)

Two weeks later...grass patches are still yellow - in some cases worse. Things have cooled down and we have had some overcast days. I'm probably going to drop some Azoxy soon to see if things are helped.

I still think this is related to some pre-emergent drops. Part of this is that there is a general stunting of growth compared to the neighbors. Roots appear to be strong still, even in the yellowing areas. Yellow areas as still only about 5-10% of the total lawn surface area. They don't seem to be growing out from the original locations.


----------



## Darth_V8r (Jul 18, 2019)

Might want to test for nematodes. The early stages mirror some fungus symptoms, and the lack of response to fungus remedies could mean it's nematodes.


----------



## UltimateLawn (Sep 25, 2020)

@Darth_V8r , interesting. I hear so much about beneficial nematodes but haven't yet tried any. There are damaging nematodes?


----------



## Ktungsten (Aug 27, 2019)

I've still got a few small yellow spots as well. Didn't use Pre-emergent this year bc of the uncertainty I had related to recovery from the snow that we had. Grass appears to be healthy otherwise so I've stopped paying attention to it.


----------



## UltimateLawn (Sep 25, 2020)

@Ktungsten , yep...no issues outside of the yellowing area other than a bit of growth rate suppression.

Million dollar question....fungus...chlorosis/iron...fertilization...pre-emergent...or just a darned result of the snow-pocalypse?


----------



## Darth_V8r (Jul 18, 2019)

UltimateLawn said:


> @Darth_V8r , interesting. I hear so much about beneficial nematodes but haven't yet tried any. There are damaging nematodes?


Oh yes there are VERY damaging nematodes. In fact, nematodes go un-noticed and open up the turf for invasion of weeds, etc, in the first place.

The beneficial nematodes I've seen are mostly grub-hunters. And they're good at it, from what I understand.

https://edis.ifas.ufl.edu/publication/ng039


----------



## ionicatoms (Mar 8, 2020)

UltimateLawn said:


> Million dollar question....fungus...chlorosis/iron...fertilization...pre-emergent...or just a darned result of the snow-pocalypse?


I fear it could also be from too much insecticide or fungicide! I couldn't figure out what was causing the yellowing in the front yard for the life of me. Million dollar question indeed. The yellowing finally faded away after trying all kinds of stuff, but honestly never got a clear indication as to the cause. Million dollar question indeed!


----------



## UltimateLawn (Sep 25, 2020)

Latest yellowing pics on this topic...


----------



## Redeyeback (May 7, 2021)

@UltimateLawn
I see we are in the same boat. I'm also in Dallas, DNT & 635. My yard is completely gone thanks to, what appears to be, the same issue.

Noticed my yard was slower to green up than my neighbors, and put down some Ironite to kick start it. Might have been a bad idea and only masked the issue as it appears to be fungal. Complete dieback in large patches. This non stop rain is not helping either.

I've had one round of Caravan G and let's call it a dusting of peat moss as a spot treatment.

The Caravan G seemed to stop the spread and was greening back up, but the weather has completely undone any progress made and sent this nasty stuff into hyperdrive. About ready to dump LCNs 4pc kit all over the place and bury it all under 2 inches of peat moss. Willing to resod as long it kills the fungi too.


----------



## UltimateLawn (Sep 25, 2020)

I'm going to do another Azoxy drop to see how things go. I've already dropped propiconazole and Clearys, so starting to mix things up. Yes...the weather this spring has been very unpredictable between hot and cold, dry and wet making this much harder to resolve itself.


----------



## CenlaLowell (Apr 21, 2017)

UltimateLawn said:


> I'm going to do another Azoxy drop to see how things go. I've already dropped propiconazole and Clearys, so starting to mix things up. Yes...the weather this spring has been very unpredictable between hot and cold, dry and wet making this much harder to resolve itself.


Yeah this weather sucks for sure. I've got GLS but it's about gone now. I see your running fungicides but make sure your on a insecticide rotation as well. As much as I hate to say it the whole growing season st Augustine turf needs to be on both program. Every year I start later than I should trying to save money on fungicides and end up biting the bullet. Same thing for @Redeyeback as well. I don't use granular at all so I have no idea of the efficacy of those products or the correct way to apply and make sure you get good coverage.

Good luck


----------



## cldrunner (May 14, 2019)

"Why is my lawn so yellow? What can I do to correct it?"

https://neilsperry.com/2021/05/question-of-the-week-may-13-2021/


----------



## Buffalolawny (Nov 24, 2018)

my 2cents

Fungus - too wet.
Iron Chelate only on affected areas. 
Soil Drench at Mix 5mL(min) to 10mL(max)in 2L of water. Apply with watering can.
or
Foliar Spray at Mix 20mL in 1L water


----------



## UncleFoolio (May 14, 2021)

Was gonna post what @cldrunner posted. Saw that yesterday, and thought of this thread.

Had the same issue the past several years, and then last year- the 1/2 that had the issue just never greened up in the spring. Was doing great going into winter. Ended up with just dirt and weeds. I'm pretty sure take all did just that- took it all out.

Just resodded that area a month ago, and plan to be much more pro-active from this point. Someone else said last week I think, but- I'm in the camp where I think I'm just gonna put down preventative rates of Azoxy every year (apr-may, oct). Also had an issue with chinch bugs last year (first year ever for that), to which...they took out an entire "right of way" strip which I also had to resod. Planning on Caravan G, which- will cover me for chinch and take all.


----------



## Redeyeback (May 7, 2021)

@UncleFoolio
Please keep in mind, using just Caravan G is not a sound strategy. Refer to FRAC recommendations and rotate your applications. Always bounce between two different MOA Groups or tank mix two different MOAs at a time.

The last thing you want is for your fungal colonies to become resistant to the Azoxy.


----------



## CenlaLowell (Apr 21, 2017)

UncleFoolio said:


> Was gonna post what @cldrunner posted. Saw that yesterday, and thought of this thread.
> 
> Had the same issue the past several years, and then last year- the 1/2 that had the issue just never greened up in the spring. Was doing great going into winter. Ended up with just dirt and weeds. I'm pretty sure take all did just that- took it all out.
> 
> Just resodded that area a month ago, and plan to be much more pro-active from this point. Someone else said last week I think, but- I'm in the camp where I think I'm just gonna put down preventative rates of Azoxy every year (apr-may, oct). Also had an issue with chinch bugs last year (first year ever for that), to which...they took out an entire "right of way" strip which I also had to resod. Planning on Caravan G, which- will cover me for chinch and take all.


Most will have

Azoxystrobin
Propiconazle
3336

and rotate like @Redeyeback said

Same with

Imiaclorpiad
Bifen

For insecticides


----------



## UltimateLawn (Sep 25, 2020)

I dropped Azoxy two days ago. Yellowing persists. Crazy rain cycles here in DFW.


----------



## Redeyeback (May 7, 2021)

@UltimateLawn 
You know what they say, "Misery loves company", and I have to admit I'm relieved to know I'm not the only one here in Dallas suffering from this mess.

If it helps, I dropped Azoxy, then 2nd app with 3336F/Prop mix. Also put down 3 cubic yards of Peat Moss and a 40lb bag of CarbonizPN. Not sure if any of it helped but the grass is greening back up and chlorosis has slowed. New growth pushing in over the bare spots. Although, this could just be from the higher temps forcing the fungi to recede and the increased microbial activity below the surface feeding the grass. Either way, its working. Hope your mess clears up soon as well. Just dont forget about it come August.

I did want to ask if you had a soil test done, and if so, what was your pH? Mine is over 7 I believe and bringing it down with ammonium sulfate could really help drive the fungi down and grass growth up.


----------



## UltimateLawn (Sep 25, 2020)

@Redeyeback , my pH measured 6.63 last December. I haven't yet tried ammonium sulfate, but a little more acid could certainly help things out a bit. Rain still coming probably won't help with yellowing.


----------



## Redeyeback (May 7, 2021)

@UltimateLawn 
I believe 6.3 is perfect for SA from what I've been reading. I would think your soil is providing plenty of exchange to provide the iron your grass needs. Lowering your pH slightly could increase your exchange but if the roots are damaged, they will not be taking up any of the nutrients.

I believe the best strategy we have is to hit it with a multi-pronged attack.

1. Alleviate compaction
2. Encourage Root Growth
3. Improve flocculation
4. Achieve and maintain pH between 6 and 6.5

Good news is this should be our last set of serious rainfall and then we start steamrolling to 110F+ days.


----------



## UltimateLawn (Sep 25, 2020)

@Redeyeback ....

1. Core Aeration...done
2. RGS - one drop, need to do another
3. Flocculation...unknown
4. pH...I went ahead and dropped some peat and mason's sand to help get a bit more water into the grass roots and eventually add a little acidity.

My lawn has been ravaged by moles and there are a lot of depressions in the surface. As part of my yearly maintenance, I'm planning to top dress with the peat and sand mix to hopefully build these areas back up.


----------



## Redeyeback (May 7, 2021)

@UltimateLawn 
Man I'm honestly nervous about sand. I see articles that its fine to amend red clay with it but not the black stuff we have here. I havent really found anything definitive yet on whether it will improve drainage or make it worse.

But boy would I love to level. Sadly I'm pretty sure all the Live Oaks in my neighborhood got bit by Oak Wilt and will need to be removed. So not much point in leveling until they are gone.


----------



## mjh648 (Sep 1, 2020)

@Redeyeback could try a sample area with sand and see how it turns out.


----------



## UltimateLawn (Sep 25, 2020)

So far my lawn has not complained at all about the sand - maybe even preferring it. My soil cores have pretty much shown that directly below the soil level is straight clay. So any sand to help the water get closer to penetrating the root zone is welcome. While not totally scientific, I can see that where I dropped the sand the water is not standing at all. I'm eager to see how the effect is working this summer with normal irrigation.


----------



## Redeyeback (May 7, 2021)

I tried to pull cores yesterday. In some areas, I was able to drive the core puller 8-10 inches. In others I couldnt get more than 2-4 inches. Even bent the tip of it and got all mangled.

Some of my cores showed good saturation in the top 3 inches but very little saturation beneath that. I believe the fastest method to amend that lower layer is with with deep core integration but will look more into sand application as well.


----------



## mjh648 (Sep 1, 2020)

Deep core integration?


----------



## UltimateLawn (Sep 25, 2020)

I hired a core service and was disappointed that the cores they pulled were no greater than 2 inches. Next time I'll rent the aerator.


----------



## kb02gt (Aug 23, 2019)

Yep used to have this a long time ago. Here is what helped.

1) this forum
2) peat moss (a lot) - drops pH, fights fungus, holds moisture
3) Seaweed - Gebberelins + Auxins are very beneficial hormones. They will keep the grass live while you make corrections.
4) Azoxy @ curative rates (4lbs/1000)
5) Cleary @ curative rates (4oz/1000) - I reserve this only for tough situations. So my grass sees something it's never seen before.
6) Aeration to get oxygen to the roots. Do not mechanical aerate near the summer, especially on a turf that's already stressed. Yes I know there are some that do not like liquid aeration, and I can understand various points to that, but in this case something that can drive bubbles deep into the soil would be fine. Sodium laurel sulphate would work well for this. 
7) remove as many fungus looking stolons as possible. Do a super light thatch raking. 
8) I'd say add 1/3lb 15-0-15. Too much N will boost the need for water. Keep using the seaweed as well.
9) make sure potash levels are up (super important) - see above
10) Make sure your irrigation stops at sunrise
11) water only when grass shows signs of dehydration, or if you need to water in a product
12)grass near the side walk will be stressed first as the concrete is usually very hot


----------



## kb02gt (Aug 23, 2019)

13) also even if you need to water in a product, try to hold off until the morning hours. Very important to not water at night. The longer the grass says wet the more difficult this becomes to treat. Also try to make sure that the 15-0-15 feet you use does contain micronutrients. No phosphorus is also important as high levels of this can also lock up nutritients.
14) A soil test is a must.
15) Try not to walk on the very stressed areas of the lawn as well.
16) An application of GrubEx + Imidacloprid + Zeta-Cypermethrin is very important. Indeed this will stress the turf a bit, but you really can't afford to skip it. The fert/micros/seaweed should help you through this stressful time.
17) Figure on $300 (very rough estimate) or so for all these products. Plus you will need some plugs. Important to get some st augustine in there that already has a good root system and wont require as much water as sod. But the plugs should come a lot later, mainly after you feel you have everything under control.


----------



## Darth_V8r (Jul 18, 2019)

Great list! How long after you apply your curatives (#4 & #5) should you expect before you see results of disease improvement?


----------



## kb02gt (Aug 23, 2019)

Darth_V8r said:


> Great list! How long after you apply your curatives (#4 & #5) should you expect before you see results of disease improvement?


Thanks. I've notice results as soon as 3 days with Azoxy and 5-7 with Clearys. But it's a bit harder to tell with Clearys cause it does make the grass a bit white. I always use Clearys with 1/2 recommended rate of blue dye.

If I see a fungus and it looks really bad I'm coming out with the Clearlys first, then again 2 weeks later. Then I will use the Azoxy. After that there really should be any problems. That first dose of Clearys really knocks stuff out for me. I had a bad case of Take All Root rot with sindged roots and after 1 dose of Clearys it was taken care of. Love that stuff, so I try to only use it in severe cases. But when I kept my watering practices the same. The TARR would come back like a month later. My pH at the time was 6.9. Also manganese deficiency can lead to TARR as well. Keep in mind I've also used Azoxy as a 1st line of attack on TARR and even though it did work, it would seem like I needed another dose. Had TARR in many areas so I guess it was a good opportunity to experiment, lol.


----------



## UltimateLawn (Sep 25, 2020)

@kb02gt , this is a great breakdown of a treatment program. Is there any full removal of TARR once you've got it?

It sounds to some degree that it will remain around even if there is a sod replacement and the best we can hope for is to knock it back and hopefully it reduces over time to a small annoyance.


----------



## kb02gt (Aug 23, 2019)

UltimateLawn said:


> @kb02gt , this is a great breakdown of a treatment program. Is there any full removal of TARR once you've got it?
> 
> It sounds to some degree that it will remain around even if there is a sod replacement and the best we can hope for is to knock it back and hopefully it reduces over time to a small annoyance.


Thanks, that's a good point. There really does not seems to be a full removal of it. However I cannot say this for sure until I've tried everything, lol. I know one of the lawn guys I spoke to said himself once you have it you always have it. I know deficient manganese can really contribute to this from what I've read. Have come close to having a good level of Mn in my lawn but I'm still deficient especially now. A
part of my current strategy here is really earliest detection possible. I used to just look at the leaves, but now, I will pull up stolons and inspect them if I notice anything off regarding the leaf blades. It's not very apparent at least to me what is happening. I look at the grass and think it needs some water, or I'll notice it's not keeping up with other areas and not pulling nutrients, if its yellowing or drying out the same day I watered it, etc. When all along the roots were rotted and could not see them. Hope this helps.


----------

