# Crazy Excessive Thatch and Everything That Comes With It



## Goater90 (6 mo ago)

My lawn was sodded about 11 years ago and has never been aerated or dethatched properly. I've gotten it looking pretty good at a higher cut but am hoping to thicken it up and start cutting low, maybe even purchase a reel mower for next season.

I recently bought a soil probe and took some cores. They revealed what looks like a huge thatch problem. Looks like about an inch and a half to two inches throughout the entire lawn. I've watched some videos online with guys saying if your thatch gets too out of hand, you'll never be able to fully rectify the problem without a complete renovation. I've read some threads on here, however, with guys claiming to have busted up quite a bit of thatch successfully.

My plan was to get a liquid thatch buster down soon, as well as get a mechanical aeration in. Then start a blackstrap molasses program every two weeks. Get another aeration in before late fall, along with a power rake and maybe a verticut, and get an overseed in right before the snow flys.

I do have some quackgrass that has crept in from the neighbour's side of the lawn. I'm hoping to paint it with roundup and get rid of it before a power rake or verticut as not to split up the roots. Would a power rake or verticut reach deep enough to split the quack rhizomes?

There is very little turf roots in the spoil at all. They seem to be completely in the thatch layer. I would think that could explain why my turf is so heat sensitive. My moisture meter shows that thatch dries out a lot faster than the soil.

I was hoping to move to a spoon feeding liquid fert program, but have read that granular works better if you have excessive thatch. Is there any truth to that?

What do you think, do I have a chance of winning this thatch battle?


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## confused_boner (Apr 5, 2021)

'Effective Microrganisms' would be one way to break down the thatch.


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## g-man (Jun 15, 2017)

Normally folks say they have thatch and post a picture not showing thatch. You do have it.

I think you should see if you can find a fixed blade dethatcher. Set it really low to get to the soil. It will destroy your nice looking lawn, but it is the way. After that, I would then do core aeration with 4-6 passes. Let the core dry on top of the lawn and then break them for a rotatory mower. This will be like a top dressing using your own soil and will bury some of the thatch. Then the last step I would do is sand topdress.

Next year, try to do the molasses as a preventive and monitor how it develops. Ensure you are not watering too frequent to encourage shallow roots/thatch.


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## Goater90 (6 mo ago)

confused_boner said:


> 'Effective Microrganisms' would be one way to break down the thatch.
> 
> I will definitely try to promote the "effective microorganisms" with the molasses program.
> 
> ...


When you say a fixed blade dethatcher, do you mean like a verticutter, or something more heavy duty? I see there is a Sunjoe power rake with a verticutter attachment on Amazon for a fair price I was thinking about buying to tear into the thatch, but it says it is only adjustable down to -0.4 inches. Doesn't seem like much when the thatch is 2 inches thick. How deep do core aerators usually go? Would they penatrate down through the whole layer? Does the thatch need to be 100% gone before sand leveling? I thought I've heard before that you don't want to end up with organic soil layering. Thanks for the info.


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## Green (Dec 24, 2017)

@Goater90

Yikes. Any idea what kind of KBG you have? The more aggressive types are known for being more thatchy.

Don't expect to solve this in a single year. You're likely going to need to dethatch both this Fall (or very late Summer, technically), and then again in April or May most likely...and possibly again the following Fall, etc., until it gets under control. And then the micro organism boosting products mentioned above can be used to hopefully help keep it from getting this way as quickly again.

Also. Do you think too much moisture is possibly an issue?


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## Green (Dec 24, 2017)

@g-man, question for you: if goater does a sand topdress, does that require a future commitment to doing so every so often forever?


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## Green (Dec 24, 2017)

Goater90 said:


> I do have some quackgrass that has crept in from the neighbour's side of the lawn. I'm hoping to paint it with roundup and get rid of it before a power rake or verticut as not to split up the roots. Would a power rake or verticut reach deep enough to split the quack rhizomes?


Not having overwhelming experience with this specific weed, I can't say for certain. But logic says it's likely. I know Poa Triv was spread by aeration and dethatching for me.


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## Goater90 (6 mo ago)

Green said:


> @Goater90
> 
> Yikes. Any idea what kind of KBG you have? The more aggressive types are known for being more thatchy.
> 
> ...


Not sure what variety of KBG the sod was. I've been thinking about calling up the local sod farm.and seeing what their sod is made up of.

Does the thatch need to me mechanically removed before the liquid dethatchers and molasses can have an effect? I was under the impression that if you got some holes aerated for the molasses to penatrate the thatch layer it would help the microorganisms break it down faster.

Not sure if it would be from excessive watering. For the first 7 or so years we owned the house I put very little effort into the lawn. It's only in the last 4 years or so that I've been looking after it more. That being said, since then I have been watering lots in summer to keep it looking good. Like I said, in over a decade this lawn has never been aerated. I have a dethatching blade for my rotary I would use once in the spring, but I've recently learned I've never set it low enough or used it properly.


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## Goater90 (6 mo ago)

Green said:


> @Goater90
> 
> Yikes. Any idea what kind of KBG you have? The more aggressive types are known for being more thatchy.
> 
> ...


Also, I guess it would be safe to say I won't be able to be mowing with a reel mower any time soon. I'll have to try to keep it long and healthy and just rip it up and rip it up for a few years. Like you say, if this is a multi year endeavor to get rid of this thatch, maybe it would just be easier to pick up a sod ripper, take the thatch off the whole yard, and start fresh with a full reno.


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## JERSEY (Sep 9, 2018)

Ill give my opinion.

KBG is my fav turf. However, I find it does produce thatch and the roots dont go deep. This is my experience.

Several ways to try to address this. Add P,K to the soil, help drive roots. Molasses is known to eat up thatch, as Gman points out. Manual dethatching--raking does help this. not in the heat though.

What I did...last year I added tttf to my turf. I find it helps the overall turf health. The tttf has significantly deeper roots, and I think some of that helps the kbg and some intertwining of roots may be occuring. The lawn needs far less watering to remain green. I dont cut short like you, or many others. I prefer higher cut for the better color and ease of maintaining it.

I would NOT rip up that turf. It looks nice....just work on it.


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## Green (Dec 24, 2017)

JERSEY said:


> What I did...last year I added tttf to my turf. I find it helps the overall turf health. The tttf has significantly deeper roots, and I think some of that helps the kbg and some intertwining of roots may be occuring. The lawn needs far less watering to remain green. I dont cut short like you, or many others. I prefer higher cut for the better color and ease of maintaining it.
> 
> I would NOT rip up that turf. It looks nice....just work on it.


As another who started with primarily KBG (plus some PR) in the front originally and added TTTF to it the second year, I agree with you on all of the above. But this strategy might not be for everyone (especially those who want a uniform, single species lawn or want to reel mow below, say, 1-1.5").

I totally agree with you that there is NO need to remove/renovate this lawn. It will bounce back from dethatching/aerating, with proper NPK inputs, even if thinned considerably by dethatching. That's such a great thing about KBG.


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## robjak (Mar 31, 2020)

Have you ever done a soil test? https://extension.psu.edu/managing-thatch-in-lawns


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## Goater90 (6 mo ago)

JERSEY said:


> Ill give my opinion.
> 
> KBG is my fav turf. However, I find it does produce thatch and the roots dont go deep. This is my experience.
> 
> ...


I was going to wait to go to a liquid fertalizer program after I found how much thatch I have, but the liquid fert I've already purchased has higher PK, so maybe it would be good to transition to spoon feeding like I had planned. Did you find the tttf made your lawn look more patchy? I would worry about green clumps wherever the fescue bunches germinated. I'm not sure the tttf would work for me, as it is my ultimate goal to move to reel mowing under an inch. If it doesn't work out however, it's definitely something I could exore further.



Green said:


> JERSEY said:
> 
> 
> > What I did...last year I added tttf to my turf. I find it helps the overall turf health. The tttf has significantly deeper roots, and I think some of that helps the kbg and some intertwining of roots may be occuring. The lawn needs far less watering to remain green. I dont cut short like you, or many others. I prefer higher cut for the better color and ease of maintaining it.
> ...


It's good to know there's still ways to get rid of all this without having to do a full reno. Thanks for the input.



robjak said:


> Have you ever done a soil test? https://extension.psu.edu/managing-thatch-in-lawns


That's a great read. I had figured there was no point in doing a soil test yet it my turf roots were barley touching the soil. Haha. That's good info. Perhaps my pH has something to do with it.


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## g-man (Jun 15, 2017)

Most people don't have this amount of thatch, so I'm not sure if the advice we give will resolve it.

Another great option is to fraze mow it.


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## Goater90 (6 mo ago)

g-man said:


> Most people don't have this amount of thatch, so I'm not sure if the advice we give will resolve it.
> 
> Another great option is to fraze mow it.


That is pretty crazy the turf can recover after that fraze mowing. I've looked around online and it doesn't look like there are any fraze mowers available near me. Could you accomplish the same thing by renting a sod cutter and setting it shallow to just take the top inch or so off, leaving an inch of thatch and roots behind?

Also, like Green asked earlier, if I were to try the aerate and verticut followed by the sand top dressing, would I have to continue with a yearly sand top dress after the thatch is gone? It makes sense to me that if I aerated aggressively, multiple passes, spring and fall for a few years and topdressed after each, eventually the whole thatch layer should almost be replaced by the sand.

For how much work that would be, perhaps a full reno would be easier/less expensive. My area is only about 750sqft, so maybe it wouldn't even be that bad price wise just to re-sod with a high quality sod.


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## g-man (Jun 15, 2017)

I dont have a lot of experience with fraze mowing or thatch in general. I could give ideas, but nothing with any experience.

The thatch layer I saw in your images looks like a live root system. I think most of ideas others posted wont help because the thatch layer has moisture and it is not just going to disappear. Hence why I think verticut/aerate will help "kill" some of it. The dead stuff will eventually decompose into organic matter.

For such a small area: gly, let it die/dry, sod cutter to remove the thatch/dead stuff and then just seed with sod quality seeds. You likely wont even need the sod cutter, just rotary mower set really really low.

I've used sand in my yard multiple times. The earthworms do mix it up and if I dig, I can't find a layer of sand.

By the way, yesterday I did a "verticut" using the 220E groomer in 4 passes. It looked horrible but after some rain last night, it looks fine now.


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## Goater90 (6 mo ago)

g-man said:


> I dont have a lot of experience with fraze mowing or thatch in general. I could give ideas, but nothing with any experience.
> 
> The thatch layer I saw in your images looks like a live root system. I think most of ideas others posted wont help because the thatch layer has moisture and it is not just going to disappear. Hence why I think verticut/aerate will help "kill" some of it. The dead stuff will eventually decompose into organic matter.
> 
> ...


Thanks a lot for all the info. If I were to try and turn the thatch around without a complete reno, would a PGR like T-nex hurt or help the situation? Would the root growth it promotes drive the roots deeper into the soil layer, or would it just promote the roots to thicken the thatch layer further?


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## Easyluck (Feb 5, 2019)

Take a plug and gently wash all the dirt away to expose the roots. You'll have a better understanding of what your dealing with.


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## Goater90 (6 mo ago)

Easyluck said:


> Take a plug and gently wash all the dirt away to expose the roots. You'll have a better understanding of what your dealing with.


That's a good idea. I'll give that a try.


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## Goater90 (6 mo ago)

After doing some more research I have come to find that the sod used to sod my yard had 15% creeping red fescue. Due to years of neglect I believe the fescue has somewhat taken over the lawn and now comprises a pretty high percentage of the turf. It sounds like the creeping red fescue is one of the most thatch prone turf grasses the is, and with over a decade of no core aeration I am guessing this is why I'm seeing the thatch that I am. The thatch buildup is so thick, that the surface of the lawn is now built up and sticks up an inch or inch and a half above the adjacent concrete. Would multiple core aerations and passes with the scarifier, but skipping the top dressing and instead raking up and disposing of the plugs for a season or two be able to collapse or sink the level of the lawn closer to the concrete level? I guess it would be trying to physically remove the thatch instead of have it decompose. Also, if reel mowing low is my end goal, is this even possible if most of the lawn is now fescue?


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## Green (Dec 24, 2017)

@Goater90, yes. With normal fertilizer (3-4 lbs of N per year) and a good amount of water, CRF, especially in shade where it does best, can get pretty thatchy, especially if the dead grass from the Winter is not lightly to moderately raked out (with a metal leaf rake) each Spring.

But normally, CRF only takes over in a low to moderate fertility environment (less than or equal to 3 lbs of N per year and possibly insufficient K). It also takes a very long time (e.g. decades) for fine fescues to take over a lawn, but I've seen it happen here, as fine fescue was traditionally extremely common here in the Northeast US, and often a predominating grass type for home lawns. FF does not normally like moderate to high fertility and water.

I would dethatch for sure. And aerate if needed. But I wouldn't bother top dressing or raking up and removing cores, because you're not doing a sand leveling. Leave the cores and let the microbes repopulate the surface. They'll break down more dead grass that way. You could also try a natural dethatch product at the same time, like the molasses.

No need for a PGR. You want normal/fast growth after stressing the lawn with a dethatching, to help it recover.

No need to renovate, unless the existing grass is not working for you once the thatch is reduced.


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## Wile (Sep 17, 2020)

I'm curious how your thatch levels are. Mine are bad as well. Did the molasses help? There's a study that tested various products, but Molasses didn't seem to reduce thatch levels significantly.


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## Goater90 (6 mo ago)

Green said:


> @Goater90, yes. With normal fertilizer (3-4 lbs of N per year) and a good amount of water, CRF, especially in shade where it does best, can get pretty thatchy, especially if the dead grass from the Winter is not lightly to moderately raked out (with a metal leaf rake) each Spring.
> 
> But normally, CRF only takes over in a low to moderate fertility environment (less than or equal to 3 lbs of N per year and possibly insufficient K). It also takes a very long time (e.g. decades) for fine fescues to take over a lawn, but I've seen it happen here, as fine fescue was traditionally extremely common here in the Northeast US, and often a predominating grass type for home lawns. FF does not normally like moderate to high fertility and water.
> 
> ...


Thanks for the advice. I've purchased a Sun Joe dethatcher/scarifier that I plan to go aggressively on the lawn with, and then will either hire or rent a core aerator and go over it multiple times like @g-man suggested. I will leave the cores and bust them up with the rotary and then I have purchased some Thatch Buster I will spray to try and promote the microbes, and repeat every 2 weeks as recommended.

I think I need to forego overseeding so I can repeat the whole process again in the spring, and then overseed an elite *** mix at that time. Correct me if I'm wrong, I would assume any new grass from overseeding would just get destroyed in the spring if I tried a heavy dethatch again?

I also think maybe it is too late to overseed. Even with pre germinating my seed, avg first frost in our area is September 10th. However, it has been an exceptionally hot August and our 14 day forecast is still showing 54f nightly lows. Maybe there is still time? Would take a week for my seed order just to get here though.



Wile said:


> I'm curious how your thatch levels are. Mine are bad as well. Did the molasses help? There's a study that tested various products, but Molasses didn't seem to reduce thatch levels significantly.


I haven't tried anything to remedy the problem yet, but am going to try an aggressive physical dethatch as mentioned above, and then follow up with Thatch Buster and possibly molasses as well. Will update with results.


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## MacLawn (Oct 26, 2021)

Goater90 said:


> My lawn was sodded about 11 years ago and has never been aerated or dethatched properly. I've gotten it looking pretty good at a higher cut but am hoping to thicken it up and start cutting low, maybe even purchase a reel mower for next season.
> 
> I recently bought a soil probe and took some cores. They revealed what looks like a huge thatch problem. Looks like about an inch and a half to two inches throughout the entire lawn. I've watched some videos online with guys saying if your thatch gets too out of hand, you'll never be able to fully rectify the problem without a complete renovation. I've read some threads on here, however, with guys claiming to have busted up quite a bit of thatch successfully.
> 
> ...


I had a similar problem on my front yard several years ago. About 1" thick and hard. When doing the "probe test" it was like sticking a pencil through cardboard box . The soil below was not compacted. So 2019 I did a extra heavy aerate 3 passes 2 @ 90 degrees and a 45' pass fall of 2021 I did a power rake and 2 pass with core aeration again.
It seems to have really helped. I can used to get standing water in front with heavy rains. It puddles now but is gone shortly after rain stops.


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## Green (Dec 24, 2017)

The biggest issue with most aerators is the maximum core depth being maybe 2 or 3 inches. Often, pulling a longer core can be helpful, and repeated shallow aeration may make a hard layer issue below worse because the roots have to stay in the loose soil later above.


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## Thick n Dense (May 7, 2019)

ii


Green said:


> The biggest issue with most aerators is the maximum core depth being maybe 2 or 3 inches. Often, pulling a longer core can be helpful, and repeated shallow aeration may make a hard layer issue below worse because the roots have to stay in the loose soil later above.


I agree the design is poor

I think in this case it shouod be ok based on the photos posted

Somone design a better aerator thats nor thousnads of dollars

You could try aerating with water pressure 
Basically blast down into the soil with high psi water 
Make a rig of high pressure nozzles that span width of mower 
The water helps bring the disturbed soil to surface

Also compost tea would be a good expermient and should supply the microbes to break that stuff down


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