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

 

I also think it is drought stress.

 

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

 

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.

 

Did you spray iron recently?

 

Did you spray iron recently?

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

 

Did you perform an irrigation audit ? Of that area?

 

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.

 

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

 

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

 

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.

 

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.

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?

 

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.

 

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.

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?

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

 

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.

 

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.

 

@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.

 

@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?

 

@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

 

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.

 

+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.

 

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).

 

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.

 

No 60min/zone today? Why not?

 

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.