Probably not form excess N. To me it does look like a different grass type. Maybe triv. Are they in sunny areas or areas that may get more shade?

Describe how you took the soil sample. I have never seen such high values of P and K. Do you have a previous soli test?

 

Probably not form excess N. To me it does look like a different grass type. Maybe triv. Are they in sunny areas or areas that may get more shade?

Describe how you took the soil sample. I have never seen such high values of P and K. Do you have a previous soli test?

Really hope it’s not triv. I have a hard time telling what triv is in person, I’m not sure if I have it or not. I’ve seen a patch in the past that had the reddish/purple stem and pulled it and never saw it again. I don’t see the ligule that identification photos online show.

A reason why I’d lean against triv is I saw spots exactly like this last year all over my smaller side yard when bombing nitrogen in the fall and don’t notice it in that location anymore.

The spots I do see it are typically full sun, some spots possibly a mix with some shade but the driveway edge for example where I see a decent amount is full sun all day.

I agree about the soil test I always thought that was strange. I took samples throughout the yard last year before seeding. I may have taken some samples from areas that had high quality top soil mixed in. I think I may retest and avoid the areas where I know that soil went down.

 

I believe it's too much nitrogen for the summer. My first year with *** as well. I over fertilized it and the whole lawn was yellow. I thought it was dead. I added no more nitrogen or supplements, just water for a month, now in August, the lawn looks amazing. I learned that *** is very resilient, just let it run its course, it will be fine.

 

Here was his summer fert

• On May 1st, I applied 0.93 lbs of nitrogen per 1,000 square feet with Lesco 25-0-6 slow release.
• On June 13th, I applied an additional 0.25 lbs of nitrogen with 46-0-0 Urea.
• On June 30th, I applied ~0.25-0.35lbs of nitrogen with a mix of 46-0-0 Urea and Lesco 25-0-6 slow release.

Not excessive,


here was his fall fert:

I was applying 0.5 lbs of nitrogen per 1,000 square feet each week using Urea 46-0-0.

Also not excessive for a Fall N Blitz. High yes but not excessive,

 

Add sulfur. The AMS bag from Lowe’s that you linked is a good start. Also, is the mowing consistent without cutting more than a third of the leaf blades? Cutting too much cause cause this appearance too.

 

@akri Can you describe how you took the samples?

 

Could it be too much N but only in certain places? I think the two doses of N in June was a bit aggressive, and if the coverage wasn't "perfect" maybe that's the issue?

OP - how are you applying your fert? The popular Scotts brand fert spreaders (with wheels) are not known to do the best job for even coverage. The lightweight construction and plastic wheels can skip in places and stop driving the rotating fert fllnger wheel, and the flinger wheel throws fert into the top of the wheels because the design is just bad... The flinger should be a few inches above the top of the wheels.

If you don't have any other issues, and you need to mow a couple of times a week to follow the 1/3 rule, I would just keep mowing and watering and re-evaluate in 4 to 6 weeks.

You may want to consider a different sort of fert for summer time application. Milorganite or similar is a good "can't lose" kind of fert for summer time use. I use the 48-0-0 in the fall and early spring... I use use a scotts' hand held/hand crank spreader on my 2000 sq ft lawn and it seems to work OK. Wouldn't want to use that spreader on anything more than 2000 sq ft tho.

 

@akri Can you describe how you took the samples?

I had bare dirt right before seeding last Spring so I took a shovel and grabbed dirt from the top few inches of soil from probably 5-6 locations from my front and back yards.

Could it be too much N but only in certain places? I think the two doses of N in June was a bit aggressive, and if the coverage wasn't "perfect" maybe that's the issue?

OP - how are you applying your fert? The popular Scotts brand fert spreaders (with wheels) are not known to do the best job for even coverage. The lightweight construction and plastic wheels can skip in places and stop driving the rotating fert fllnger wheel, and the flinger wheel throws fert into the top of the wheels because the design is just bad... The flinger should be a few inches above the top of the wheels.

If you don't have any other issues, and you need to mow a couple of times a week to follow the 1/3 rule, I would just keep mowing and watering and re-evaluate in 4 to 6 weeks.

You may want to consider a different sort of fert for summer time application. Milorganite or similar is a good "can't lose" kind of fert for summer time use. I use the 48-0-0 in the fall and early spring... I use use a scotts' hand held/hand crank spreader on my 2000 sq ft lawn and it seems to work OK. Wouldn't want to use that spreader on anything more than 2000 sq ft tho.

Using the Echo RB60. Typically I mow every 3-4 days and abide by the 1/3 rule. A few points this summer I'd get a bit unlucky with rain and had to push an extra day or two out. I have a zero turn and a lot of hill so I don't like to mow until the ground is pretty dry.

I'll continue to back off for the next few weeks and when things cool down start the fall nitrogen blitz.

------

I've been looking for information on this issue over the past few days and haven't found anything solid. I did find a few interesting videos/discussions. I don't think by any means this is what I have going on but the lighter grass blade issue is fairly similar.

Turfgrass Diseases Flourish as Rain and High Humidity Persist Throughout Pennsylvania | Penn State Turfgrass

A Summer Only a Turf Pathologist Could Love - Genesis Distribution

This summer has been hot (numerous days ≥ 90oF and most nights > 70oF) and humid; marked by periods of drought; then broken intermittently by a few rainy days and […]

www.genesisturfgrass.com

Etiolated tiller syndrome, the blades in the photos appear more isolated than what I have in the first link. The second mentions chlorosis but my soil test had adequate iron levels. The slow release fertilizer I put down earlier this Spring/Summer had Iron.

I came across this video and it mentioned a few possible causes but one in particular was high salinity levels and needing gypsum. My sodium levels in my soil test didn't seem too high (are these the same thing?).

I'll likely take another soil test to see if there's anything I'm missing.

The reason I'm still leaning against triv is this spot here:

2023 Fall Nitrogen Blitz, showing the same issue I see this year in 2024

2024 same spot, don't notice lime green, if this was triv I'd imagine it wouldn't look great by now?

It's not in this particular spot anymore but across the lawn in other areas.

Thanks for all the input to everyone so far

 

Full sun spots are most likely not triv.

I came across this video and it mentioned a few possible causes but one in particular was high salinity levels and needing gypsum. My sodium levels in my soil test didn't seem too high (are these the same thing?).

I do doubt you have a salt (salinity) issue. Gypsum is calcium sulfate, which would add sulfur as @secured2k recommended.

I would want to know how the P and K got so high and will super high value of P affect anything. if you do decide to do another soil test please buy a soil probe.

Amazon.com : soil probe

 

Waypoint Analytical would be my choice. Do the soil test in March.

 

When mine is growing like gangbusters in the spring, I get this effect too. Lime green patches mixed in with dark green patches. Lasts two to three weeks or so. I believe it's related to the grasses in the mix - possibly one getting real dark while the other is looking for more nutrients.

When my lawn gets stressed and long, particularly at the edges of my driveway, I also have a tendency to get the lime green color, but more single blades than patches.

I do have problems with triv, and I don't think this is the same (sunny areas) - unless the triv is much more prevalent in the lawn than I realize and quickly fades in favor of other grasses when this starts to appear.

Either way I don't know the cause, but following here as well.

 

Been wondering this myself. I have a mix of Midnight/Mazama. Some of my bluegrass is super low, dark green in a few spots. Wondering if that's the difference in cultivars or maybe the soil profile in that spot. I had a blend when I seeded my lawn initially but need to seed another spot this spring and I have 2 individual bags. I'm going to plant both in pots and see if I can tell the difference lol.

Idk about your soil profile or what you typically use but this fall for the blitz I'll be trying ammonium sulfate with sulfur for a few weeks straight and see if that helps with the lime green. The spots by my driveway get really intense, very lime. It's almost like it looks bleached.

 

Low sulfer at 11ppm will cause this.