# Why is my grass disappearing?



## Canuck Mike (Jul 23, 2018)

It's happening again, I had this issue last fall. I've over seeded with PRG September 2018 and a month ago, had new growth and things were looking great. Then within a week it started thining out. It's very disheartening. Any ideas whats going on here?





I don't see any browning or wilting, it's like spots of grass has just disappeared.


----------



## Canuck Mike (Jul 23, 2018)

Can anyone help me rule out what is not causing this? 
Could it be a disease?
Could a bug do this?
It is a no mix with prg and kbg overseed and I cut reel low, perhaps some grass type is not liking the hoc.
Could it be that I cut it daily and it's been very wet this year, too much ware?


----------



## Pawel (Feb 1, 2019)

i'm no expert but that doesn't look like disease/bugs to me because the space is just "empty" (no dead/yellow grass) and surrounding grass looks healthy. PRG won't fill in those spots on its own. if this was kbg it would fill in those spots nicely (as long as it's something i'm not familiar with causing these) if this was my yard, besides posting here asking for advice - i would stick a probe in few spots to see what comes up and would pick a small section of these spots and try dropping some seed and see what comes up.

did you put down any compost during overseed? i did once and didn't spread it out enough in some places so it clumped up and next spring i had similar spots (definitely not that many/uniform)


----------



## Canuck Mike (Jul 23, 2018)

Pawel said:


> i'm no expert but that doesn't look like disease/bugs to me because the space is just "empty" (no dead/yellow grass) and surrounding grass looks healthy. PRG won't fill in those spots on its own. if this was kbg it would fill in those spots nicely (as long as it's something i'm not familiar with causing these) if this was my yard, besides posting here asking for advice - i would stick a probe in few spots to see what comes up and would pick a small section of these spots and try dropping some seed and see what comes up.
> 
> did you put down any compost during overseed? i did once and didn't spread it out enough in some places so it clumped up and next spring i had similar spots (definitely not that many/uniform)


Thanx for the response, no compost with the overseed, just Scotts starter. I did the overseed 4 weeks ago and this is my lawn 10 days ago.



Then I got showered with seeds from the maple tree.



I don't have a probe but i have a home soil test kit. My pH in march was 7.5 but I'll check it again and see what I get. Thnx again.


----------



## g-man (Jun 15, 2017)

How much shade do you have? What type of tree is that one? Black walnut? Is the lawn thinning everywhere or only under the tree?


----------



## Canuck Mike (Jul 23, 2018)

It's a maple tree, lots of blossoms have already fallen and now the seeds are raining down.
It seems to be all over unified. But it is a big tree.


----------



## LIgrass (May 26, 2017)

Canuck Mike said:


> It's a maple tree, lots of blossoms have already fallen and now the seeds are raining down.
> It seems to be all over unified. But it is a big tree.


How much direct sun would you say it gets? That to me looks like sun-starved PRG. It won't tiller much so it will never look full if there's too much shade. PRG needs full sun to shine. KBG won't spread much in deep shade either (maybe Bewitched would do ok) but I suspect there's probably very little KBG in there .


----------



## tgreen (Oct 20, 2018)

Doesn't make sense the lawn would develop those spots over 10 days with no signs of dead grass or disease. Did you start mowing shorter? It looks like my lawn early in the year when it's just breaking dormancy. Squirrels can cause those spots but hard to believe they could do that much damage that quick.


----------



## social port (Jun 19, 2017)

@Canuck Mike Do you have a video recorder that can capture at night? A lawn-cam that you could use at night?


----------



## Canuck Mike (Jul 23, 2018)

LIgrass said:


> Canuck Mike said:
> 
> 
> > It's a maple tree, lots of blossoms have already fallen and now the seeds are raining down.
> ...


It only gets early morning and evening sun. That could be the answer to why it was doing well till the leaves on the maple were large enough to block out the sun.


----------



## Canuck Mike (Jul 23, 2018)

social port said:


> @Canuck Mike Do you have a video recorder that can capture at night? A lawn-cam that you could use at night?


No I don't but I'm intrigued, what were you thinking of, night crawlers? I do get a lot of worm dropping mounds in late fall.


----------



## krusej23 (May 8, 2018)

I would say it's either worm castings or did you just rake up the newly seeded grass that had maybe grown an inch or so. When you raked up the blooms, you could have raked too hard.


----------



## critterdude311 (Apr 21, 2018)

LIgrass said:


> Canuck Mike said:
> 
> 
> > It's a maple tree, lots of blossoms have already fallen and now the seeds are raining down.
> ...


My experience with PRG was similar. I have had an area of primarily PRG under a large tree. It pops out and looks great in the early spring. As the tree leafs out later in the spring and the shade becomes heavier the PRG thins out and or becomes patchy. My conclusion after a few years has been the area doesn't get enough direct light for the PRG to thrive. TTTF May be a better alternative for areas like this.


----------



## social port (Jun 19, 2017)

Canuck Mike said:


> social port said:
> 
> 
> > @Canuck Mike Do you have a video recorder that can capture at night? A lawn-cam that you could use at night?
> ...


I was thinking that a camera would be a way to determine if some kind of pest is causing that damage.

Edited to add: But it sounds like you are getting some good feedback for the shade theory.


----------



## Kmartel (Feb 12, 2019)

I don't know what's causing your sudden bare spots but I can tell you need to adjust the reel to bed knife on your mower OR get it sharpened. The cut looks terrible, leaving jagged edges and you can see it causing dieback of your shoots.

How long have you been mowing low? And what is low (actual bench hoc)? If you went from 2-3" to under and inch an a week or 2 that could explain the bare spots, they were always there just not visible at higher hoc.


----------



## Canuck Mike (Jul 23, 2018)

Kmartel said:


> I don't know what's causing your sudden bare spots but I can tell you need to adjust the reel to bed knife on your mower OR get it sharpened. The cut looks terrible, leaving jagged edges and you can see it causing dieback of your shoots.
> 
> How long have you been mowing low? And what is low (actual bench hoc)? If you went from 2-3" to under and inch an a week or 2 that could explain the bare spots, they were always there just not visible at higher hoc.


Yes I need to send the reel to be stone sharpened, I've back lapped it and it will cut paper but not the full length of the reel. No matter how much time I spend adjusting it.


----------



## tgreen (Oct 20, 2018)

Canuck Mike said:


> Kmartel said:
> 
> 
> > I don't know what's causing your sudden bare spots but I can tell you need to adjust the reel to bed knife on your mower OR get it sharpened. The cut looks terrible, leaving jagged edges and you can see it causing dieback of your shoots.
> ...


Did you start mowing lower though? I agree with kmartel this would be the explanation. Are the pics you showed with no spots mowed high and then you went low that revealed the spots. That seems the only plausible explanation to me.


----------



## Canuck Mike (Jul 23, 2018)

Did you start mowing lower though? I agree with kmartel this would be the explanation. Are the pics you showed with no spots mowed high and then you went low that revealed the spots. That seems the only plausible explanation to me.
[/quote]
No the hoc was actually lower in the pics with no spots. I was mowing at that hight for a few weeks and I've raised the hoc by 1/8th 2x since the spots showed up and they have grown in numbers.


----------



## Canuck Mike (Jul 23, 2018)

@tgreen I agree it's very strange to see spots of missing grass, I actually thought my toro gm 500 was dripping oil because of how uniform the spots appeared.


----------



## Kmartel (Feb 12, 2019)

What is your HOC? 
I am not totally convinced it is a shade issue but if it is then raising you HOC should help. This will provide more leaf surface for photosynthesis. I am not talking going up to 4" where it flops over and stays wet all day.


----------



## Canuck Mike (Jul 23, 2018)

Kmartel said:


> What is your HOC?
> I am not totally convinced it is a shade issue but if it is then raising you HOC should help. This will provide more leaf surface for photosynthesis. I am not talking going up to 4" where it flops over and stays wet all day.


My bench hoc was 3/4 and is now 1 1/8. These conversations are very helpful. After obsessively thinking about this for days now I believe it is a combination of prg not thriving in the shade and worm dropings from last fall that have been flattened by the roller. It didn't make sense that It looked good at 3/4 if they have always been there unless........
When the maple blossoms/seeds started falling I began using my grass catcher to help in the clean up, therefore it is possible that the clippings that I normally let fall were hiding the bare/worm spots.
The clipping have stayed green and not browned in the garbage bin for days. 
Im not 100% convinced they could mask so many bare spots though. 
I'll be overseeding with a more shade tolerant grass and ill be keeping my hoc above 1" and see how it goes. 
Thanx to TLF for all the info.


----------



## Canuck Mike (Jul 23, 2018)

Update
I now believe the reason for the spots is earthworms/nightcrawlers droppings.
I read somewhere that the worms are drawn to organic matter like compost. In fall 2018 I mulched the leaves from 3 large maples with my rotary mower into the lawn. There were a LOT of leaves.
The issue with the droppings is when I mow low with the gm500 the rollers squish down the droppings.

Fall of 2019 I bagged all my clippings and raked all leaves before mowing.
This spring I have very few worm droppings and my lawn is much thicker.


----------

