# Excessive thatch



## MNReel (Jul 18, 2018)

Hey all,

My wife and I just bought a house last year in the MSP southern Metro area. This is in a new development and was previously owned by someone who hired their lawn service. This whole area was sod not seed. Last summer we didn't try really hard as I had no clue what I was doing. I've learned a lot from many of you (Connor ward, Ryan Knorr, Allyn Hayne, etc.). I knew I had a thatch issue but I didn't know how bad. I took the grass down to 1 1/2" and took a dethatching rake to a small section. I ended up ripping up my turf. It appears all the rhizomes were branching off in the thatch and non of the roots actually went into what appears to not even be black dirt but a mix of clay and black dirt. Please help me figure out what this is and if I can fix it.

Thanks in advance


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## Wlodyd (Aug 27, 2018)

I'd probably core aerate this spring... That's beat way to reduce thatch layer. Then just go through a good fert program this year an either core aerate again in the fall, or you may consider a power rake. I think the core aeration will help remove thatch and open the soil to let the roots and rhizomes drive down into the soil.


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## MNReel (Jul 18, 2018)

I have a verticutter/slit seeder. I don't know if that will go low enough though. Thoughts?


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## Jconnelly6b (Mar 4, 2018)

Try you verticutter if you have one. Do a small area and see what comes up. It might be all you need.

If you want to remove without mechanical action, find black strap molasses and dilute in warm water and spray on the lawn. It will feed the microbes that break down the thatch. There are quite a few resources on the internet for this technique.


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## Wlodyd (Aug 27, 2018)

I agree, use what you have to start.... I'd go on the lighter side anyway and break it up a little at a time in spring and fall. Use the verticutter this spring, treat with N-Ext D-Thatch (or molasses as menyioned, but just wanted to give you a product to look into) and then aerate in the fall. You don't need to completely rip it all out in one go and probably don't want to.


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## MNReel (Jul 18, 2018)

Thanks All,

I'll verticut at 1/4" into the thatch layer and then depending on how it recovers and what the weather looks like in 6-8 weeks i may do another round and then repeat in the fall. I measured 4 other areas last night and had ~1.15" of thatch on average throughout those 4 spots all were fairly similar. I spoke to a neighbor as he was watching me mow my lawn to prepare for verticutting last night (no one else in the neighborhood has touched theirs yet) and he was telling me the previous homeowner used TruGreen for their lawn care service. I have a hard time believing that from what i know about Trugreen. I will continue to update with pictures as i go through the season.

Thanks again for the solutions so far.


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## DiabeticKripple (Apr 14, 2019)

you could do a light power rake to get some of the thatch removed, then do a verticut to cut through it.


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## MNReel (Jul 18, 2018)

Quick update.

I rented a power rake and did a pass and pulled up enough thatch to fill 5-55 gallon drums from about a 90'x30'. I then took my slit seeder/verticutter and did a pass north to south. This pulled another 6-55 gallon this was more of that thick spongy thatch. I then went east to west with the vericutter. It pulled another 4 barrels out and I still am not seeing dirt in some areas. I am going to leave it at this point and top dress with black dirt and reseed. I'll put on some tenacity and starter fert.


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## Jconnelly6b (Mar 4, 2018)

Going to reiterate a biological solution. Any and all mechanical options are hard for turf to react to because they occur so quickly.

Now that you have removed most of the thatch later, molasses will break down (slowly) the final bit, while in the process creating food for your turf.

Seeding at this point in the year will be a risk - it's quite possible all the new grass won't make it through the heat of summer. Even profuse watering has shown little impact on spring seeded turf grass.

Throw some nitrogen on your existing lawn, watch it spread and fill in, and sow your seed in the fall.


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## MNReel (Jul 18, 2018)

Thanks @Jconnelly6b

I actually have some lawn microbe liquid coming and I did purchase some black strap molasses as you mentioned. I do have a few bags of milorganite and I have some 7-1-2 fert (I can't remember the brand) we have a good amount of rain coming this next week which is why I rushed to get this done before Monday. I still have the other 5,000 sq ft of my lawn to do hahaha. I plan on following the same process. But, I do want to compare molasses and microbes vs mechanical dethatch. I may just do that with my test area I plan on making into a raised garden bed next year.

This being my first post on the lawn forum I have to say everyone on here is awesome and extemely helpful! Thanks all.


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## Jconnelly6b (Mar 4, 2018)

@MooreGreen55020 we are happy to have you here!! :beer:

Hopefully you feel as welcome and find the forum as helpful as I have.

Your milo will help break down that thatch layer as well - if you put that down and then spray the molasses you should see improvement in a month or so. The biological solutions are not quick fixes, but much better for the health of your turf in the long run.

It would be very interesting if you could do a test zone with only bio action vs. the areas with mechanical and bio action.


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## MNReel (Jul 18, 2018)

I included a map. 
I'm a scientist at heart. Being that i studied molecular and cell biology for my bachelors I figured i will set up an experiment. My lawn is 100% the same across all 7000 sq ft. I'm laying out a double blind study. 
Q1 - Mechanical Dethatch and Milo.
Q2 - Biological Dethatch and Milo. 
Q3 - Mechanical Dethatch and 7-1-2 fertilizer I have if I can find another bag of it ( if i can't what else would any of you recommend?).
Q4 - Biological Dethatch and Same fert as Q3.

I will continue to use Humic and Fulvic. We are expected to get rain 9 of the next 15 days so i'm not sure how much watering i'll be doing.

I am testing out a product I found online called Hydretain. I got a free 10,000 sq.ft ready to spray bottle of it so i figured what the heck.

I will record whats going on and what I do. i'm not one to make a youtube video but, I'm going to take @wardconnor's advice and just do it! Hope to see which one works best and hopefully it helps someone in the future not have have to expiriment and let me make the mistakes. My wife will probably kill me if i kill the lawn but it's grass it will grow back or they always sell more seed.


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## g-man (Jun 15, 2017)

Awesome. Not really a blind study since you know the inputs. 

I think every study should have a control. What about a section of just fertilizer?


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## MNReel (Jul 18, 2018)

True @g-man ! more of just a cross study. I would probably need to split 2 sections as a control but I did just fertilizer (Milo) last year. I knew I had a thatch problem last year but didn't know how much was on the turf. This year I'm getting into the "I want to have the best lawn in town" mentality. I didn't see any difference from spring last year to this year if anything the latch was worse. Huge brown dead spots after the grass woke up. Now you have my brain really cranking.


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## Wlodyd (Aug 27, 2018)

Officially subscribed to this thread and looking forward to your results (and video!). Post updates here.

I hit my yard hard with he power rake last year and filled 20 refuse bags of that material. I overseeded and threw down Milo with it. My lawn looked rough for 3-4 weeks, but now my grass is greener than it's ever been and growing in well. Wondering what else works with that strategy!


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## MNReel (Jul 18, 2018)

We had an excellent weekend for getting in the lawn. Attached is a picture of the thatch pulled out of zone 1. This was the 4th pass I don't know how I had any grass left but it's still green and I'm seeing dirt finally. I purchased some biological dethatching mix off amazon which has molasses in it. It also has 5% humid acid and 3% fulvic so that's a bonus. I threw down my milo. Best part was all the neighbors that stopped by to talk about lawn care. They saw me working on it at 10am and went got out their mowers after. So far the mechanical did take out quite a bit of the green grass but not even close to half. I filled over 20 drums of thatch but now it's time to water and spray down some of this bio dethatch liquid.


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## DiabeticKripple (Apr 14, 2019)

Your lawn will thank you in the long term!

I did one pass with my sun joe a couple weeks ago, I took some soil samples today and was looking at the turf at the soil surface and I still have a bunch of thatch there.

Tomorrow I will do another pass or two. I already got 6 black garbage bags of grass off a 3000sqft lawn with the one pass.


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## MNReel (Jul 18, 2018)

@DiabeticKripple what do you think of the sun joe. I thought about getting that instead of the slit seeder so that I can do a light power rake instead of doing it by hand. Electric equipment just scares me for some reason. I have someone who wants my slit seeder in trade for a 2001 toro greensmaster 1800 (needs some work) but am hesitant as the slit seeder is the only means i have of getting the thatch out.


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## lobitz68 (Mar 21, 2019)

MooreGreen55020 said:


> I am testing out a product I found online called Hydretain. I got a free 10,000 sq.ft ready to spray bottle of it so i figured what the heck.


More info on the FREE part please? I want free Hydretain...


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## DiabeticKripple (Apr 14, 2019)

MooreGreen55020 said:


> @DiabeticKripple what do you think of the sun joe. I thought about getting that instead of the slit seeder so that I can do a light power rake instead of doing it by hand. Electric equipment just scares me for some reason. I have someone who wants my slit seeder in trade for a 2001 toro greensmaster 1800 (needs some work) but am hesitant as the slit seeder is the only means i have of getting the thatch out.


I've only used it once. It was my girlfriends grandfathers and I got it when he passed away.

But it works really good. It's light and powerful. It's got all the different height settings too.

The only thing is if you get it the thick stuff, it overheats and trips itself out. Then you have to wait 20 mins for it to cool off before it will turn on again


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## MNReel (Jul 18, 2018)

@lobitz68 I found it online doing some research and I was discussing it with a neighbor who had the granular version and the liquid version who claimed it was junk and just gave what he had left to me. I was looking at his lawn last year and he has a lot of thatch (worse than my lawn I'd say around 1 1/4") which I am questioning if that caused it not to get into the ground or if he didn't water it in???? i have no idea what he did but he bought it because he was spending $100+ a month on just keeping his lawn green in the summer so he went all in and probably didn't use it correctly. I've heard great things from everyone else i know who has used it just not this guy. it's fairly cheap if it works. last year my lawn went dormant in late July and bounced back at the end of August if I remember correctly. This guy also had like 10 bags of Scott's turf builder last year and was putting it down once a month. This year he purchased nothing but Milo via myself and my other neighbor. I don't think Hydretain is overly expensive unless you have a large lot.


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## Jconnelly6b (Mar 4, 2018)

@MooreGreen55020 I have the Greenworks and it's great. Used for 2 seasons before overseeding with good results.


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## MNReel (Jul 18, 2018)

Well, some weeks have gone by and here's what I have so far.

I added my rgs last week which as usual kept the areas that were green growing and flourishing. The dead brown areas .... crickets.

The mechanical dethatched areas are a mix some areas I'm seeing great progress others I think I killed my lawn. The biologically dethatched areas are still patchy and I'm not noticing any progress on the thatch going away. I've applied the blackstrap molasses 2x now. I added some lawn microbes to the mix. Could just need some heat to get going. Minnesota is struggling to get above 60 consistently. I will oversees this fall as the back yard is embarrassing. This may be a master plan to rip it all up and start new! Hahaha my wife isn't too happy.


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## DiabeticKripple (Apr 14, 2019)

Patience grasshopper.

Thatching is hard on the lawn, so it will look beat for a bit. In another month or two it will look amazing!


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## Jconnelly6b (Mar 4, 2018)

If it's not above 60° then those microbes are barely waking up. Another couple weeks for sure.


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## MNReel (Jul 18, 2018)

@Jconnelly6b & @DiabeticKripple haha I know I'm waiting. It's just sad seeing the yard all beat up. We have to do some major leveling in some areas so I always joke with my wife that I'm going to kill it all and start over but the areas that need fixing isn't worth it. We have a few days in the 70s with the lows in the 50s so we should see some better results. This is a year round project to get my lawn ready to mow under an inch. I did go and trade for the greens mower and bought a sunjoe!


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## MNReel (Jul 18, 2018)

Update:

We are on day 2 of pretty consistent rain. The grass seed is coming up pretty good and am noticing my kbg spreading. After my 3rd app of molasses the biodethatched areas are starting to reduce in thatch but very slow. The rest of the mechanical dethatched areas except 1 are coming back strong and lush. The one area that is struggling is the area where my thatch was over an inch and a half and the root structure was in the thatch. Last night we got over an inch of rain and I noticed that we have a major low spot right there. Right now there is a quarter inch of water sitting on top and the soil under it is completely saturated. Could this be what was hindering the thatch from being digested in this area?


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## MNReel (Jul 18, 2018)

7 Week Update. (I will add pictures after my mow tonight).

Attached is the data I've been collecting from my weather system. 


So I have been applying 2 oz of molasses per K. The thatch has kind of stopped breaking down in the biodethatched areas or just slowed down even more (I believe this is due to the rain we have been getting. I have decided I am going forward with installing a french drainage system from my roof gutter down spouts to a large catch basin (250 gallons if my city approves it which they should because it's far from any structures) as well as 2 lines of french drains along the low spots about 16-18" deep. In the low spots the color of my lawn is mixed between dark green and light green I'm assuming it's from the water pulling the micros down deeper and diluting everything. the rest of my yard where I did mechanical dethatch and have good drainage the lawn is thicker and a dark green. I'm cutting at about .9-1" high at my lawn has a darker green than my neighbor who is cutting at 3". parts of my front lawn are so thick that my little manual reel mower is washboarding so I need to bring it up to about 1.5" and use my Toro. I need to find a decent powered reel just on a budget.

This summer I will be doing the french drain system and then this fall I have roughly 60 cu yds of compost coming in (mixture of grasses, horse poop, chicken poop, bon fire ash, and random browns from what the farmer said). I will be using this to level my lawn so I am going to mix core aeration and using my brand new SunJoe scarifier (thanks for the recommendation I tried it on my side strip I originally had biodethatched and it's just as good as the gas powered slit seeder or better if you don't mind flinging a cord around. I will continue to use molasses because I do see the benefit but not the method I like for removing the waste. Again, I will post pictures of the lawn right after I mow tonight.

I want to thank everyone who has commented, helped or followed hopefully it helps someone.


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## MNReel (Jul 18, 2018)

The first 2 and the 4th pictures are from the mechanical dethatched the 3rd, 5th and 6th are from the bio area. 
The 2nd picture is where I'm getting poplin water.


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## MNReel (Jul 18, 2018)

Just completed a last minute mow between storms. Had to increase my height of cut to 3"  due to being so busy and wanting to spend the time I had after work with my wife and baby boy. Just thought I'd post a picture of the front lawn. This was the area that was mechanically dethatched and receives the most sun and heat. I have not watered once due to all the rain!


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## Jconnelly6b (Mar 4, 2018)

Looks fantastic! Sounds like you will have your hands full this summer fixing all the drainage - best of luck!


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## MNReel (Jul 18, 2018)

@Jconnelly6b yeah my wife has an excellent idea to block off the back yard with a retaining wall on both sides of the house smh. Just running some estimates before we either shut that down or go for it. I thought to myself if we go with it I will invest in an auto mower for the back and stick with the mission to get the front down to under 1". The front yard is roundhouse 10' higher in elevation than the back yard that run practically the length of the house. I am beyond appreciative of everyone's input


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## Mnbadger (Jun 9, 2019)

Where abouts in the south metro are you? I'm in farmington. I've also been trying to get a handle on my lawn. Good luck


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## MNReel (Jul 18, 2018)

@Mnbadger I'm in Elko New Market. I work near the Lakeville Farmington line. Btw love the screen name! Originally from southern Wisconsin and big badgers fan!


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## Jconnelly6b (Mar 4, 2018)

Looking back at your pictures, those brown areas that are still vacant of grass may have been grub damage, or hit with some fungus late in the year. For that grass to die and mat down like that, usually something significant occurred.

Did you do a preventative grub treatment this year?


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## MNReel (Jul 18, 2018)

@Jconnelly6b I did GrubX in the spring and fall last year (first year in the house and didn't know what I was dealing with yet). I will be reapplying it again every fall as to my understanding that's the best time. It could be a fungus issue I have not done anything to treat it because don't you usually see the white hyphae or rhizoids which i have not seen that but I may look into an anti fungal ... any recomendations? it would make sense to be fungal since the worst areas are typically very wet and stay wet for days after a rain and last year I didn't know what i was doing with watering and watered every other day for about 20 minutes a zone which was about 1/3 of an inch. Up to giving it a try.


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