# 2020 Winterizing Experiments Index Thread plus Green's Early vs. Late Winterizer Experiment



## Green (Dec 24, 2017)

This thread will serve two purposes:
1. Index of all 2020 Winterizing experiments
2. To post my own 2020 experiment

Edits will be continue to be made to this post. Check back regularly for updates and additions. If you're performing an experiment, tag me in it and I'll post a link to it here. So far, we have 4 people doing experiments.

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Links to results - 2021 (check back often as they will be updated):
https://thelawnforum.com/viewtopic.php?p=349270#p349270

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My 2020 experiment: early versus late Winterizer:

This year, I'm going all-in with a new approach. I'm putting my previous winterizing method (which itself was a modification of the traditional/old-school method) up against a new method.

Additionally, I believe at least one other member is planning to recreate a simpler version of my 2019 experiment (which did not pan out due to a Poa Triv infestation that confounded my observations, and flooding which prevented me from accessing the area to observe it).

Links to all experiments will be posted in this thread. In my case, the test areas will not receive any Spring Nitrogen fertilizer until May 15th. This way, Spring performance or lack of, will be attributable to the Fall fertilization/winterization used in 2020.

Also, @g-man is performing the same experiment as @kay7711226. His experiment can be found here: https://thelawnforum.com/viewtopic.php?f=9&t=24982


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## Green (Dec 24, 2017)

Details of experiment #1:

Traditional after-growth stops winterizer vs. pre-slowdown winterizer

I marked off a test plot in the main front and will apply my traditional after-growth fertilizer of choice to it. Half will receive 0.5 lb/M of N, and half will receive 1.0 lb/M of N. The fertilizer will be Scotts 27-0-2 Green Max, which is mostly fast release N, and also contains a good amount of methylene urea. Link to test plot applications: https://thelawnforum.com/viewtopic.php?p=352891#p352891

The rest of the yard received a custom blend of methylene urea on October 28th. The day before, we received about 1/3 inch of rain, and in the two days following the application, we received roughly 2.3 inches of rain. There has been no rain since then (2 weeks).

Details of custom methylene urea blend:

My blend went down at 0.75 lb N, and contains:
-0.25 lb N from Scotts Green Max 27-0-2
-0.25 lb N from Lebanon 27-0-5
-0.25 lb N from Nitroform 39-0-0

The breakdown: About 0.28 lb of fast release N from Ammonium Sulfate and standard Urea was applied, and 0.47 lb slow release N from the Methylene Ureas/Urea Formaldehyde. Some of that is similar to fast release and becomes available within 2-4 weeks. Other fractions are longer duration release such as up to 2-4 months. And at least 0.10 lb of the 0.75 lb total N is even longer term...6 months or more. As microbial action decreases with lowering temperature, Nitrogen release rate will decrease accordingly. The idea is to simulate tapered spoon-feeding and also have a bit left for greenup in Spring, as methylene urea does not leach easily.

Rationale and history:

After using Green Max as my winterizer for several years, I noticed robust Spring greenup. It has worked better than straight urea ever did for me as a final app. I attribute that to the methylene urea.

Additionally, I kept track of neighboring lawns and when they were fertilized. Most lawns that were fertilized in the final week or two of October had excellent Winter color as well as decent Spring green-up. In some years, my Thanksgiving/early December Winterizing application produced visually better results, other years about equal, and in some years worse. I never noticed stress or disease issues on these lawns such as snow mold.

Finally, we keep hearing in the latest research about how N dropped too late in the season tends to be a waste and gets lost to leaching. What do the experts now promote as a better winterizing method instead? Tapering off and fine-tuning spoon-feeding to insanely low N levels through the season until growth stops for all intents and purposes. That is a lot of labor, and requires spraying...which requires lack of wind and no leaves on the lawn. It's not practical for many of us. I wanted to see if a single application could replace the final 4-6 weeks of spoon-feeding. A predominantly methylene urea blend was the logical method to use to test this out based on my past experience with it, as well as its N release properties, which are microbial dependent, and therefore also temperature-dependent.

Evaluations:

I will take photos within several days of the late Nitrogen application. I will also attempt to do a few photo updates during the Winter. Regular updates will occur beginning in Spring of 2021, prior to green-up, and will occur at least every two weeks during the Spring.

I will also offer subjective evaluations of color and quality, and will measure the rough growth rate as well.

Bonus experiment:

Test area 2 will receive *both *applications, as follows:
-October Methylene urea/fast release blend AND 0.75 lb/M of 46-0-0 urea after growth stops. The idea here is to see what happens if both treatments are performed in the same area, versus only the early treatment in the adjacent area.


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## Green (Dec 24, 2017)

Links to Results (links to first sets of photos and results through March 2021):

Green's 2020 Experiment:
https://thelawnforum.com/viewtopic.php?p=369219#p369219

kay7711226's 2020 Experiment:
https://thelawnforum.com/viewtopic.php?p=367113#p367113

g-man's 2020 Experiment:
https://thelawnforum.com/viewtopic.php?p=362492#p362492

bernstem's 2020 Experiment: 
https://thelawnforum.com/viewtopic.php?p=363715#p363715


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## Oneacer (Sep 27, 2020)

I am just putting one of the bags of winterizer I have on hand, which will probably go down today, as I do my last leaf clean up and final mowing for the season. ... believe its 26-0-09 ... Done ...


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## Lawn Noobie (Sep 29, 2020)

Following (hoping for pictured results)


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## jtuber (Sep 15, 2020)

How do you keep track of when neighboring lawns get fertilized? This could be creepy.


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## Green (Dec 24, 2017)

jtuber said:


> How do you keep track of when neighboring lawns get fertilized? This could be creepy.


Not that hard. Most have application signs with the date listed.


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## Green (Dec 24, 2017)

First evaluation:

No difference visually yet between the winterized area and yet to be winterized area.

No photos just yet.


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## PompousPilot (Sep 19, 2018)

It would only be creepy if Green had a ghillie suit on with binoculars laying in a leaf pile.


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## Green (Dec 24, 2017)

So today if I really look, I think I can see a tiny difference between the areas that were already winterized and the area that has not been winterized yet. The yet-to-be winterized test area doesn't look quite as good as the winterized area near it, but it's subtle. There should be no surprise here, though...fertilized grass always looks better.

I'll be taking photos in the coming week, but I doubt the differences will be visible in them. Couldn't take pictures yet due to the leaves.

The real test will be after both areas are fertilized, seeing how they compare over the Winter.


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## Green (Dec 24, 2017)

The Nitrogen went down on the test plots today:

500 square ft. main front test plot:
-0.5 lb/M of Nitrogen from Scotts 27-0-2 Green Max as I've done the last few years. This is a methylene urea, urea, and AMS blend. This plot received only this app and the Fall blitz, but not the pre-pause winterizer.

125 square ft. side front test plot: 
-1.0 lb/M of Nitrogen from 46-0-0 urea as is traditional. This plot also received the Fall Blitz, AND the pre-pause winterizing app. The goal is to see if two different winterizing apps are better than just the pre-pause app (which most of the yard received in addition to the blitz).

Rain is coming tomorrow. Soil temps are around 40F. Photos will be taken starting next week.


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## Chris LI (Oct 26, 2018)

Following


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## badtlc (Aug 22, 2019)

after reading those recent studies of late fall nitrogen application, put me in the boat that putting N down for winter is completely wasted but I will gladly follow your test to see what happens in your 2 setups.

Good luck.


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## Lawn Whisperer (Feb 15, 2021)

Any photos?


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## Green (Dec 24, 2017)

Lawn Whisperer said:


> Any photos?


I'll be posting my first sets of evaluations soon. Not all evaluations will have photos, due primarily to snow. But check back for the photos from December and January, which I'll be adding with their respective evaluations.


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## Green (Dec 24, 2017)

First set of results - Through March 2021:

Notes:

In the future, I plan to standardize all photos to the overhead view. I will also take all photos at roughly the same time of day going forward. Also, I will include all three image locations for every date going forward.

Early N applied on 10/28/2020.

Late N applied on 12/11/2020.

Photos through March 2021:

*Forum software seems to resize images and quality is lowered. Right click image and select "view image" for full size image.*

*Do not compare photos horizontally! These are different areas/views. Compare dates by going up and down only.*










Subjective impressions and measurement data to be added soon; check back again.


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## Green (Dec 24, 2017)

@bernstem, looking at your results and comparing to mine is interesting. At this point, I think I may be starting to see the later-fertilized areas starting to pull ahead slightly. But it's too early to note a difference for certain. From a distance, I think I'm noticing a greener color in that area along the rough boundary of the applications. (I'm kind of single-blind as to where the cutoff point is, because I didn't mark one of the areas, but did note the measurement so I can check it with the tape measure).

It also appears that the area that received BOTH the standard methylene urea app + the unstabilized late 46-0-0 winterizer may start surge-growing soon once the temps warm up. That's not a desirable outcome as far as I'm concerned. Sort of like what's happening to my neighbor's yard where his dog-pee spots from the Winter are starting to surge-grow after he put down a pre-M with Nitrogen in it last week. (His soil temps are higher due to more sun and he always greens up earlier as a result, all other things equal.)

I wouldn't be surprised if the later-treated area pulls ahead and looks slightly better during April, but then it reverses in May as the steady-release Nitroform in the early-treated area starts to release more and cause that area to look better as the more-active MUs wear off.

As a confound, there was a slight temp-difference for a while in the double-treated area...it was a few degrees F higher than the adjacent area, which I did not expect as I thought I picked areas that would have uniform temp differences. As of the other day, the two areas equalized in temp. I saw another such color/greenup boundary within the early treatment area as well (and there's no significant temp differencs).


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## JERSEY (Sep 9, 2018)

I cant get close up shots to see the differences.

what is your feelings on the results?



Green said:


> First set of results - Through March 2021:
> 
> Notes:
> 
> ...


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## Green (Dec 24, 2017)

JERSEY said:


> what is your feelings on the results?


It's too early to tell; we are a bit behind in green-up this year in my immediate area. I'll have to wait for full green-up and then see what happens to even begin to make any fair comparisons.


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## bernstem (Jan 16, 2018)

I definitely saw the Xgrn area green up faster then the Methylene Urea. Even now when I am mowing 2-3x/week, the stabilized Nitrogen area is growing better, but the difference is not huge.

The only Nitrogen so far this year on the back was 0.15 as a foliar application on 3/14. I applied Primo on the same day at a low 0.2 rate.

I'll try to see if can put together some photos of the areas, but I have been quite busy lately with non-lawn stuff.


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## Green (Dec 24, 2017)

The area that got double fertilizer apps is definitely greener, but it also seems to be growing vertically faster, almost too fast. And that was just with 46-0-0 as the final app, stacked on top of the methylene urea/urea/AMS blend that I used for the early app.

I'm not really sure what's going on, but I'm starting to think that a late Winterizing application promotes faster green-up and growth out of the starting block in Spring regardless of what may have been done before it. I won't know for sure what's going on for a few more weeks.

But this brings up a question: What is the end goal of Winterizing late? Even if it greens up slightly faster and grows slightly faster the first few weeks, is this important or even desirable? What if the slower-to-wake-up turf is focusing more on root growth and less on top growth? How much N is actually stored as Carbohydrates over the Winter, versus just sitting in the soil all Winter and then mineralized and uptaken in early Spring?

bernstem and I used the exact same methylene urea fertilizer blend and similar timing (with respect to our habitual first frost dates). Methylene urea is noted for stability over time. It would make sense that the stabilized urea had faster greenup, but I am surprised that the XGRN (which is organic with AMS, essentially) promoted the fastest greenup of everything. G-man noticed something similar, I believe. Maybe the answer is in my question...specifically the organic components.

Studies show that so little N is uptaken in cold weather, and that leads me to wonder if the results we are all seeing are more due to lingering N than carb storage...especially since I'm seeing the beginning of what I think might be surge growth on the double treatment area. My soil has a good amount of organic matter...about 5%, so it's not unthinkable that unstabilized N could linger all Winter.

My neighbor's dog pee spots from like January (on top of snow at the time) are surge growing in a similar manner right now.

If only I knew a bit more about soil chemistry, I might be able to figure out whether all of these situations are cases of N lingering over Winter rather than carb storage...but it sure seems like it to my eye without running any experiments to actually measure it.


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## Green (Dec 24, 2017)

This all leads me to another possible experiment, but I'm not sure how you'd do it...

Applying a final Winterizer app to one area, not applying it to another, and then somehow measuring the early Spring N levels in the soil in both plots.

Is this a doable experiment for us next year? Maybe someone more knowledgeable with soil chemistry can tell me if it is feasible to do or not.

Man, I think it would sure answer a big question, though.

By the way, is anyone aware of existing research on this topic?


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## bernstem (Jan 16, 2018)

I don't know of any for lawns, but there is a lot of research for commercial crops looking at spring growth, Nitrogen levels, and crop performance with fall fertilization. Much of the data I can find on Nitrification inhibitors are from those sources and they certainly show carryover into the spring from fall application.


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## Lawn Whisperer (Feb 15, 2021)

Green said:


> This all leads me to another possible experiment, but I'm not sure how you'd do it...
> 
> Applying a final Winterizer app to one area, not applying it to another, and then somehow measuring the early Spring N levels in the soil in both plots.
> 
> ...


The purpose of the nitrogen blitz is to promote root growth and store the nutrients (all, not just N) in the grass over the winter, then use those stored nutrients in spring.

It's not the amount of nitrogen that's in the soil when spring comes, but the nutrients the grass has taken.
This evident in highly fertilized sod is placed on soil with low nutrients. An example is when a newly installed sod in late fall/early winter, it will green up quickly in spring regardless of the nutrient in the soil.

IMO, a better experiment would be, to do a tissue test on the grass at the end of a nitrogen blitz or even at green up the following spring.


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## Green (Dec 24, 2017)

We might have to combine a soil Nitrogen test (is there such a thing?) and a tissue test to really understand what's going on. The more I think about this, it seems like one or the other doesn't tell the full story.

Ok, here are some questions.

-What types of Nitrogen tests are available for testing soil?

-Are there tissue tests for both N and Carbohydrates as well?

We really want to know how much soil N is being carried over through the Winter, and then how much is making it into the plant in the Winterized and non-Winterized areas.

Without doing a soil Nitrogen test, we don't know if the growth response is coming from previously stored carbohydrates, from rain, or from N that's already in the soil.


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## Green (Dec 24, 2017)

Lawn Whisperer said:


> It's not the amount of nitrogen that's in the soil when spring comes, but the nutrients the grass has taken.
> This evident in highly fertilized sod is placed on soil with low nutrients. An example is when a newly installed sod in late fall/early winter, it will green up quickly in spring regardless of the nutrient in the soil.


Yes, but how do you know the growth response is not due to N from the soil being utilized? That's why I say you need to test soil N to see if it's carrying over through the Winter You can't assume the growth response is from resources stored in the plant prior to Winter. Take the Winter dog urine situation as another example of this.

I never saw surge growth in Spring when I winterized in other, previous years. (I did see early greenup, though.) But it looks like the area that received both treatments is about to have both happen (It already greened up faster and is now starting to grow longer than the other area). Not only that. The lawn also had the standard N blitz prior to both of these applications (though not the most aggressive version possible...a more toned-down version was used). And yet I'm still seeing what sure looks like a difference developing in the double treated area. And the fact that the only difference between it and the other area was an additional app of unstabilized 46-0-0 at the very end of the season, makes me wonder what's really happening. There should be a limit to in-plant resource storage. And why would such storage result in Spring surge growth immediately after greenup? My gut feeling tells me surge growth is associated with concurrent utilization of soil-available Nitrogen, not previously stored resources. But I don't know if the science backs this up.

And this is all a little premature. I don't know for certain if I'm starting to get more rapid growth...I'll need to wait another week at least in order to tell for sure. None of the above in the past few posts is an official observation for this thread yet. It's more just me speaking aloud about what I've seen since the last official evaluation date. Only the dated posts and photos are official. I will post the measurements of blade length gathered as part of that soon. it would be bad science to offer opinion in the middle of an experiment, but since this is a discussion forum, we are free to do so as long as we don't lose sight of the actual results.


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## Green (Dec 24, 2017)

bernstem said:


> I don't know of any for lawns, but there is a lot of research for commercial crops looking at spring growth, Nitrogen levels, and crop performance with fall fertilization. Much of the data I can find on Nitrification inhibitors are from those sources and they certainly show carryover into the spring from fall application.


I bet there's enough similarities in some of the plants they used. If even forage or crop grasses like wheat or something were used, you could surely generalize to turf grass...as long as they're all cool-season grasses.

Next step is more waiting and more data collection. If the data match my latest interim observations of growth rate, etc., then I'll need to start researching this stuff to learn about the utilization of Fall-applied N over the Winter and into the Spring. Biggest question is, how much can stick around in the soil? The stabilized N studies probably go into this and compare to stabilized N (because that's one of the supposed selling points of the technology...extending how long it's viable in soil).

Additionally, with something like XGRN, I have to wonder if it's behaving like stabilized N.

Would you comfortably feel like concluding that if stabilized N has truly improved the greenup and increased the early-Spring of your turf, that you could attribute the effect to soil-available Nitrogen in early Spring (versus attributing it to carbohydrate storage prior to Winter)? I think you can see where I'm going with this...


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## bernstem (Jan 16, 2018)

@Green I do think that the earlier green-up is due to more available spring Nitrogen. It fits with other observations in the lawn. For example, areas under trees tend to green up slower than adjacent areas even with similar sunlight. The one caveat is that the Xgrn area had extra Potassium going into winter. That is definitely a confounder.

AS for the ag data, Corn is very similar to turf, but... Corn is an annual and doesn't have to deal with the potential negative effects of increased early season growth. In a corn field, there is nothing to pull the nitrogen out of the soil other than environmental factors.

I think an interesting comparison should be between organic Nitrogen (like the Xgrn 8-1-8), Stabilized Nitrogen, and Methylene Nitrogen. Add a touch of fast release to each formulation and see which performs better in the spring.


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## bernstem (Jan 16, 2018)

Green said:


> We might have to combine a soil Nitrogen test (is there such a thing?) and a tissue test to really understand what's going on. The more I think about this, it seems like one or the other doesn't tell the full story.
> 
> Ok, here are some questions.
> 
> ...


There are a lot of Nitrogen tests available for soils. Most commercial labs can run that without problems, and Waypoint has several test suites with Nitrogen in them. We tend to ignore them as levels are highly variable, but for this it makes sense.


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## Green (Dec 24, 2017)

I'll have the next batch of updates soon.

In the interim days, I want to share an observation. One of my neighbor's lawns (South facing direction) stayed extremely green this Winter compared to everything else I saw. And it also greened up faster than many this Spring. It's a generally average quality lawn. Mows low (about 1-1.5 inch) with a tractor. He's a bit of an old-school gardener, but doesn't do a whole lot with the lawn. I asked what Nitrogen was applied this past Fall. He said a late September app. And he said he put down a Winterizing app in November on impulse because he had it and figured why not put it down. The Winterizing N had a mix of fast-release urea, AMS, and methylene urea. I don't know what rate was used or the exact timing it was put down. But I thought I'd share what I saw and found out about it. This is someone who does not soil test, and has used minimal inputs most of the time. Total N last year was around 3 lbs; more than in past years. Very little Potassium.


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## g-man (Jun 15, 2017)

@Green per the other thread, these pictures (more like a screenshot of a word doc) are very hard to see. The site has not image software. It needs the images hosted in an online location and using [ img] with the address. You can use the Add image to post that helps uploading to postimage like most members use.


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