# Black Spots In Lawn



## Ohio Lawn (Mar 20, 2019)

I have some darker (almost black) spots in my TTTF front yard. I can see them clearly at a distance, but when I get right on top of them and look at the grass, I don't notice anything. 
The area gets full sun and is being irrigated about every 5 days. What is this?


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## CTJomh (May 24, 2018)

I am sure the experts will chime in but I would look at drought stresses. Either irrigation or something under the soil etc.


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## greencare (Sep 14, 2019)

I also think it is drought stress.


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## CarolinaCuttin (Sep 6, 2019)

Drought stress. First stage of wilt is leaf blade getting thinner and color going dark green/purple.


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## davegravy (Jul 25, 2019)

I had something similar looking in March and April, but it wasn't drought stress given the soil moisture I had. Dunno what it was but it went away after a month. It thinned out my grass a bit.


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## SNOWBOB11 (Aug 31, 2017)

Did you spray iron recently?


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## Ohio Lawn (Mar 20, 2019)

SNOWBOB11 said:


> Did you spray iron recently?


I sprayed 0-0-2 micro Greene about 2-3 weeks. But that's the only time.


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## g-man (Jun 15, 2017)

Did you perform an irrigation audit ? Of that area?


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> Did you perform an irrigation audit ? Of that area?


Not yet. I need to. You think it's draught related? Maybe that area is not getting hit with the irrigation as well.


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## g-man (Jun 15, 2017)

Possible, that's why you need to do an irrigation audit.


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## Ohio Lawn (Mar 20, 2019)

Ok I'll do that tomorrow and get back to this.


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> Possible, that's why you need to do an irrigation audit.


I did an irrigation audit this morning. I was surprised. I ran each zone for 20 minutes and it was consistent among the zones, but it was only 1/4" of water in each container. Right now I have my controller programmed to run each zone for 20 minutes every 5 days. Which was probably fine during the rainy month of May, but now that there is less rain, I am way under 1" per week. I'm guessing that's not good since my grass was just planted from seed this past September.

I also read that heat stress can cause darker spots. Any thoughts on syringing? (irrigating for about 5 minutes around 2:00pm to cool the sections that get full sun all day)

I am interested to hear thoughts after this info. 
Thanks everyone.


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## davegravy (Jul 25, 2019)

Ohio Lawn said:


> g-man said:
> 
> 
> > Possible, that's why you need to do an irrigation audit.
> ...


Good idea to up that runtime but it doesn't explain why this discolouration is happening in the spots you showed only.

Did you compare how much water the black parts got versus parts of the lawn that look normal?


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## g-man (Jun 15, 2017)

Set it to 40min every 3 days. Do another audit. Make sure you place a can in the dark spot and in the green area for that zone to check for even distribution.

You should run the 40min now to get the soil back to proper moisture.


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## Ohio Lawn (Mar 20, 2019)

davegravy said:


> Ohio Lawn said:
> 
> 
> > g-man said:
> ...


Yes, they all got about the same. 1/4" of water in 20 minutes of irrigation. I'm confused.


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> Set it to 40min every 3 days. Do another audit. Make sure you place a can in the dark spot and in the green area for that zone to check for even distribution.
> 
> You should run the 40min now to get the soil back to proper moisture.


Ok I can do that. I'd like to find a way to run half the zones one day and half on the other, since I have 8 zones. I gotta mess with my Hydrawise controller today. Side note, I was planning on applying Azoxy & Prop today as a preventative, along with some 0-0-2 micro green. My plan was to spray it with my backpack sprayer and let is sit. Should I spray now and just water it in? My purpose was for prevention of brown patch and/or grey leaf spot, since my lawn is new.


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## davegravy (Jul 25, 2019)

Before you water, if you have a soil sampler, pull some soil cores to see what your soil moisture is like. If it's damp then that adds further to the mystery.


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## bernstem (Jan 16, 2018)

@Ohio Lawn Both of those are systemics and can be watered in. If you want to prevent root diseases they need to be watered in as they only move upward in the grass.

Those areas may have differences in soil texture, drainage, or overall grass health leading them to develop drought stress earlier with the same amount of water applied. Most lawns will have areas that show stress before others. Consider them your Canary for when to water.

@davegravy has a good idea to pull a core and see if the soil is moist. It will also let you look at the grass roots and soil in the area. Pull a core from the good area and you may have an answer in the comparison.


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## Ohio Lawn (Mar 20, 2019)

@bernstem @davegravy i pulled plugs in the dark area and the normal area. The plug on the left is from the dark area. The plug on the right is from the normal area.

The plug from the black area is noticeably drier and more crumbly. The black area plug was also harder to get through to get the plug.

Thoughts?


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## davegravy (Jul 25, 2019)

Ohio Lawn said:


> @bernstem @davegravy i pulled plugs in the dark area and the normal area. The plug on the left is from the dark area. The plug on the right is from the normal area.
> 
> The plug from the black area is noticeably drier and more crumbly. The black area plug was also harder to get through to get the plug.
> 
> Thoughts?


Looks like you have double the depth of water penetration on the normal area compared to the black area, so if the irrigation system is distributing water evenly it suggests compaction.

I'd give it a really good soak and confirm with the probe you get moisture down to a 6" depth. Then adjust your run time and watering frequency to make sure the deeper soil isn't drying out like that.

If you have clay soil you might need to put breaks in your watering to allow absorption /prevent runoff. E.g water 30mins, rest 30mins, water 30 mins. While watering check for standing water. Adjust your break lengths so they're long enough to minimize standing water. Zero point in putting down water on top of standing water, you're watering something somewhere downhill

Plan to address compaction. I have sandy soil so don't know much about this but I think aeration and soil softeners are options. Aeration is typically spring /fall but soil amendments may be applied now


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## g-man (Jun 15, 2017)

Based on that image, run the system for 60min, now. I would avoid propi and green effect. Do azoxy if you want while the system is running. Setup cans in the dark area and green area.


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## bernstem (Jan 16, 2018)

+3 you need to water. Check the dark area after watering to see if you are getting penetration. I would also do a more detailed irrigation audit while you are watering. It can be hard to see differences in precipitation with just 1/4 inch of water. I would plan on getting 1 inch down in the dry areas.

Compaction can be addressed with soil conditioners (liquid aeration products) and/or core aeration. If you want a quick soil conditioner, you can use cheap shampoo with SLS (Sodium Laureth/Lauryl Sulfate) in it at 2-4 Oz/1000.


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## g-man (Jun 15, 2017)

I was in a rush typing earlier. Propi is a dmi that has pgr effects to it. The area looks water stressed. I don't think you should stress it more with stuff right now. Water it. Get the soil moisture back on track. In Indy, I'm at 0.20in of water per day, per the ET calculation. If you were doing 0.25in every 5 days, you likely depleted all the moisture. The ideal is to keep the moisture level above 50% (don't empty the bank account).


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> I was in a rush typing earlier. Propi is a dmi that has pgr effects to it. The area looks water stressed. I don't think you should stress it more with stuff right now. Water it. Get the soil moisture back on track. In Indy, I'm at 0.20in of water per day, per the ET calculation. If you were doing 0.25in every 5 days, you likely depleted all the moisture. The ideal is to keep the moisture level above 50% (don't empty the bank account).


Well I was about an hour late in reading this post. I already applied Azoxy & Prop (at the minimum rate) before I read this. I did give it a thorough watering afterward though. It started to get late in the day, so I plan on running the irrigation in that area again tomorrow morning, then rechecking the good and bad areas with the soil probe afterward to check the moisture depth.

@davegravy I changed my irrigation schedule on my Hydrawise controller. I set each zone for 40 minutes every 4 days. I have the "cycle & soak" set up so it will water each zone for 20 minutes, then come back and water them all again for another 20 minutes after all the other zones have run. This should help me some. I also ordered more small cups so I can do a more thorough irrigation audit.

I might hit the darker areas (or maybe the whole lawn) with some Air-8 to start working on any compaction. I also plan on aerating in the later summer/early fall prior to overseeing.


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## g-man (Jun 15, 2017)

No 60min/zone today? Why not?


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## davegravy (Jul 25, 2019)

Yeah I would do a deep soak asap, don't wait for your next scheduled watering. That'll give you a starting point you know is good, then monitor things with your new schedule.


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> No 60min/zone today? Why not?


I got home late and thought I'd water it tomorrow morning instead of at 6pm today. Maybe I should have. I'm going to water tomorrow for 60 min per zone.


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## Ohio Lawn (Mar 20, 2019)

davegravy said:


> Yeah I would do a deep soak asap, don't wait for your next scheduled watering. That'll give you a starting point you know is good, then monitor things with your new schedule.


I'll do 60 minutes per zone tomorrow morning.


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## Ohio Lawn (Mar 20, 2019)

I fully agree that the dark spots are drought stress related. The only thing that's confusing to me still is I thought drought = brown areas. I've never seen almost black areas like this before.


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## g-man (Jun 15, 2017)

How many inches in the two cans after the 60min?


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> How many inches in the two cans after the 60min?


After doing a full sprinkler audit, I found that in most zones I am getting 0.6 inches in 60 minutes.


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## Ohio Lawn (Mar 20, 2019)

Fellas, its getting bad again. Temps have been around 80 but with the full sun the Accuweather "Real Feel" says 87 degrees. And we've gotten no rain lately. The dark spots are going crazy and in those areas the grass blades are noticeably much more thin than in the nice looking areas. 
Thoughts?


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## ABC123 (Jul 14, 2017)

That's drought stress.


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## Ohio Lawn (Mar 20, 2019)

Should I water immediately or wait until morning?


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## davegravy (Jul 25, 2019)

Ohio Lawn said:


> Should I water immediately or wait until morning?


I'd wait but dig some plugs asap and check what the moisture levels are like in those areas versus others.


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## ABC123 (Jul 14, 2017)

Ohio Lawn said:


> Should I water immediately or wait until morning?


If you have a in ground system run each zone for 60min each and time the watering to end just before sun up. 3 days later do 40 min each.

Lots of places are wicking 1.5in+ of rain this week, it's very dry out there.


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## g-man (Jun 15, 2017)

g-man said:


> Based on that image, run the system for 60min, now. I would avoid propi and green effect. Do azoxy if you want while the system is running. Setup cans in the dark area and green area.


Did you setup cans in the dark area and light area? What are the measurements for each?

Are you doing each zone every 3 days at +45min each?


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## Ohio Lawn (Mar 20, 2019)

@davegravy


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> g-man said:
> 
> 
> > Based on that image, run the system for 60min, now. I would avoid propi and green effect. Do azoxy if you want while the system is running. Setup cans in the dark area and green area.
> ...


I did put cans in the good and bad areas. I got mixed results. Some cans had 0.4" and some had 0.6". I have been running each zone for 40 minutes every 4 days. I set those run times before I knew my output. So I think I'm not running them long enough. I have to reprogram my controller.


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## g-man (Jun 15, 2017)

0.4 in 60min? You have to set the system up to get the lowest amount to be 0.5in.


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> 0.4 in 60min? You have to set the system up to get the lowest amount to be 0.5in.


Ok I'll reprogram to get 0.5. Should I do every 4 days or go to every 3 days?


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## g-man (Jun 15, 2017)

3 days. And as things get worst, every 2.5 and then every 2 days.


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## davegravy (Jul 25, 2019)

Hard to tell from photos sometimes. How deep is the soil moist?

Are the bad area cores short because you couldn't push your probe any deeper? Or they broke because the roots are shorter here?

The next watering don't set a time limit for it, just keep it running and dig cores every 30 mins until its soaked a good 6" down. Consider this an emergency measure to stop your grass going into dormancy.

After that you can get back to figuring out what's wrong with your soil and /or tweaking your watering schedule.


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## Ohio Lawn (Mar 20, 2019)

davegravy said:


> Hard to tell from photos sometimes. How deep is the soil moist?
> 
> Are the bad area cores short because you couldn't push your probe any deeper? Or they broke because the roots are shorter here?
> 
> ...


The bad area cores are 2" long and moist about 1". The good area cores are about 4" long and moist all the way.

The bad area cores are so short because that is the deepest I could get the soil probe. It was hard just to get that deep. The area was very hard.


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## davegravy (Jul 25, 2019)

Sounds like your soil is compacted and water just can't penetrate. I'll leave it to others here to recommend things for compaction (I have sand and no experience with compaction)

In the short term though you gotta find a way to force water down further... That might mean longer run times with lots of breaks to allow water to soak in so it doesn't run off.


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## JERSEY (Sep 9, 2018)

Mr Ohio.
it needs water. run the irrigation. pound it. this will help until mother nature chimes in.

been hot and dry

blast it with water


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## g-man (Jun 15, 2017)

^ +1

@JERSEY is right. It just needs water. Last week it needed water and so this week.


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## Ohio Lawn (Mar 20, 2019)

Thanks everyone. I pounded it with water and its looking much better. It still a tad brown, but nowhere near the purple/black that it was. I did a more thorough sprinkler audit also. I had to adjust some sprinkler heads to get better coverage. I had a bunch of I20 rotors that I decreased the radius on when I turned on my system in the spring, using the radius screw, and I wasn't getting head to head coverage anymore. For some reason I thought one sprinkler head should only go half way to the adjacent head. I didn't understand head to head coverage. I am now getting head to head coverage with more consistent precipitation in each area.

I am now running they system for 60 minutes per zone which gives me 0.5" of water. I have my controller set to water every 3 days and I will keep a close eye on it. It's amazing how quick it responds to water.
Thanks again.


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## Blazethetrails (Jun 19, 2020)

Ohio Lawn said:


> I have some darker (almost black) spots in my TTTF front yard. I can see them clearly at a distance, but when I get right on top of them and look at the grass, I don't notice anything.
> The area gets full sun and is being irrigated about every 5 days. What is this?


Beautiful lawn


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## davegravy (Jul 25, 2019)

Ohio Lawn said:


> Thanks everyone. I pounded it with water and its looking much better. It still a tad brown, but nowhere near the purple/black that it was. I did a more thorough sprinkler audit also. I had to adjust some sprinkler heads to get better coverage. I had a bunch of I20 rotors that I decreased the radius on when I turned on my system in the spring, using the radius screw, and I wasn't getting head to head coverage anymore. For some reason I thought one sprinkler head should only go half way to the adjacent head. I didn't understand head to head coverage. I am now getting head to head coverage with more consistent precipitation in each area.
> 
> I am now running they system for 60 minutes per zone which gives me 0.5" of water. I have my controller set to water every 3 days and I will keep a close eye on it. It's amazing how quick it responds to water.
> Thanks again.


Great!


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## g-man (Jun 15, 2017)

i-20 should give 0.4in/hr so you are close. I'm glad it is improving.


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## Ohio Lawn (Mar 20, 2019)

Quick side question;
Now that it's not suffering from drought stress as bad, should I apply a bit of nitrogen? Say 1/4#/m?
The only reason I ask is because my lawn is less than one year old. Planted it last fall. 
(I've applied about 1.25# so far this season. Last app was 0.75#/m of CarbonX on May 20th.)


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## g-man (Jun 15, 2017)

Forget about a calendar. Is it healthy? Then do nothing.


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## Ohio Lawn (Mar 20, 2019)

g-man said:


> Forget about a calendar. Is it healthy? Then do nothing.


I don't mean to sound dumb here, but how do I determine if it's healthy? Visual appearance? 
There yellowing in a couple small areas but I just attributed that to my soil ph/iron relationship. Other than that it looks decent.


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## g-man (Jun 15, 2017)

Yes. Good color, it has some growth, it looks good.


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## JERSEY (Sep 9, 2018)

I agree with G-man.

leave alone.....keep watering.....

been brutally dry here in NJ. Water is most important to me right now.


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