# Fall Nitrogen: How much and how long?



## Captquin (Aug 22, 2019)

I've read the Fall N Blitz and Transition Zone Blitz, but wanted to dedicate a thread to this.

Some folks say 2-3 lbs total N for the fall. Others say .25-.5 lb N/M per week until it stops growing. Most agree that quick release is the way to go, especially later in the season.

Certainly grass type will matter. I know in my lawn, the KBG clearly grows taller than the TTTF when aggressively fed. That said, the TTTF still grows.

Thoughts?

@j4c11 @vnephologist


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## j4c11 (Apr 30, 2017)

Bluegrass in the transition zone is a different beast, because it's more cold tolerant than fescue and winters are mild. I've had years where it it grew through the winter and I had to mow every two weeks all the way into spring. Another interesting data point is that at least for my area, soil temps remained in the ideal range for bluegrass root growth fall through spring with the exception of February when they dipped slightly below. So you're dealing with almost an inversion of growing season with bluegrass this far south. Clearly that's going to be dependent on temperatures, some winters are milder than others. Having said that, as long as the bluegrass is growing I continue to apply fertilizer through winter at the 0.5lb N/k rate per month, and 1lb N/k during fall. 6-8 lbs N per year is about where I'm at total.


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## Green (Dec 24, 2017)

0.25 to 0.50 every other week until the end of the growing season is likely too much. The weather causes a slowdown eventually. Too much fertilizer during that time is often wasteful and could contribute to disease or hardiness issues over Winter. But that doesn't necessarily mean that all inputs need to halt when the growth slows. Rather, inputs need to be continuously decreased. By the time growth stops, applications should be minimal. 0.25 is likely too much by that point in time, unless you're doing an old-school winterizing scheme.

As far as total amount, it depends on how long your Fall is and the condition of the lawn and its fertilization history. Lawns in better condition need less obviously.

I used to do too little N fertilizer in the Fall. I now find about 2 lbs to work well. That's the idea of the blitz. You can also add tapered micro-feeding after the slowdown starts, if needed. The longer your Fall is, the more apps you may find needed.


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## Captquin (Aug 22, 2019)

Thanks. I want to push root development but have read something about applying too much and carbohydrate stores, etc. Don't really understand it. I need to find some more in-depth literature


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## JERSEY (Sep 9, 2018)

I would feed it till it stops growing. 0.5 lb every week or so in fall.....more if you want to push it.

then add a little more a week or so later.

diff opinions.......but mine loves N P K great time to push it. all the beat up areas fill back in ..in the fall with a push of food.


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## bernstem (Jan 16, 2018)

I don't think that typical recommendations for fall Nitrogen work in areas of the transition zone where you will see little to no dormancy. As an extreme example, look to the south where cool season grasses are over seeded into Bermuda to keep winter color (anyone watching the Masters and scoping their PRG over seeded Bermuda?).

Unfortunately, it is hard to give a blanket recommendation since growing conditions vary greatly over the winter in the transition zone. Green touches on what I think is likely the important point. My take is that you should match Nitrogen inputs to growth. If the grass is growing 1 inch/week, it needs more fertilizer than if it is growing 1 inch per month. The net effect will be a gradual tapering of Nitrogen into the fall and early winter with likely stopping of Nitrogen in middle winter depending on weather and the grass.

The need for a "winterizer" Nitrogen composed of a high dose of fast release Nitrogen just as the grass is going dormant is under question even farther north. In the transition zone, I think it has even less relevance and timing it can be particularly problematic. I have done it in the past, but haven't noticed any huge benefit so I don't bother even trying any more. I just let my Nitrogen match growth and taper off as the days grow shorter and cooler.


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## Virginiagal (Apr 24, 2017)

@Captquin This article on cool season turfgrass roots may be of interest. It's old but explains a lot about the cycle of root growth and decay.
https://archive.lib.msu.edu/tic/tgtre/article/1996feb1a.pdf


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## rockinmylawn (Mar 25, 2018)

I follow the recomendations in VA to limit TTTF/KBG to <=3.5lbs of N/K for ENTIRE year.
So for me in central VA - that means: 3.5 lbs of N/K split between 2 seasons really: 1 lb of N in Spring & rest in Sept -Dec.
Spoon feeding weekly (<0.25lbs N/K) has actually been less stressful knowing I have 4 to do in October & November 

https://www.dcr.virginia.gov/soil-and-water/fertcalc

https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/CSES/CSES-135/CSES-135-pdf.pdf (page 7)


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