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Best N-P-K for fall application?

16K views 40 replies 17 participants last post by  Nitroman  
#1 ·
I had I always thought that in the fall that you should you use a lower Nitrogen level and higher Phosphorus and Potassium. With grass preparing to go dormant i dont see why you would want to increase N since that helps promote growth. I like to feed the roots with P and help vigor with K to help survive winter better.

The guy at Lesco told me that all the golf courses order 32-8-4 now. The idea is that the plant builds up N then uses it up in spring to encourage greener lawns.

Would most of you guys agree with Lesco? What NPK are you guys using and why?
 
#2 ·
I agree with the higher P & K on the last visit. In some cases, you can overdo the Phos and you should probably test.

Using high N just before the plant stops growing does increase carbohydrate storage for winter and allows for early spring green up.
Think about it, at the beginning of the route, much of the N will be used up. But since they will be the first ones done in the early spring, it works out.
The last ones done in the fall need the early green up since you may not get there until later in the spring.
 
#6 ·
It seems there are different theories on the last Fall application. However how this is handled depends largely on the type of turf as well.

With Bermuda, my last application of the year has high Potassium to help with Winter stress from cold temps. If the lawn is deficient in Phosphorous, I would use a 9-23-30 for example. Otherwise, 8-2-34 would be the choice.

I'm not a believer in applying high N during the last application. It causes top growth when the plant is in the process of storing carbs for dormancy. By pushing N, you interfere with natural processes.

And Timturf will be quick to point out here that the use of SOP for your Potassium was proven to provide faster greenup the following Spring.
 
#10 ·
This is one of the old great debates I'm told. Personally it depends on the lawn and whens my last application. I do not believe in a one size fits all aproach. For example if I'm doing a lawn that requires a early fall app,(sept) then I will use higher N content but with higher Slow release (poss a 32-0-10 75%scu 2% fe)
if the lawn is a later fall application then I swich to a 20-0-20 50% scu 2%fe). And if its a really late application, say first to second week in Nov and the cold is comming on strong, I will switch to a 16-0-31 or therebouts. I don't want to push the N late in the fall. Here, the grass is naturally slowing down its growth anyway, there is no need for alot of top growth. Typically the falll lawns are always my favorite, Little stress, optimum growing temps, they look great.
I guess if you look at the awnsers, I'm somewhere in the middle of the debate.
 
#11 ·
And for the record....companies like Tru Groin, and specifically Tru Groin uses the same high N stuff they use every other app which is totally wrong for the area.

Im still of the opinion that my area and basically the upper midwest needs high K, weak N, and No P.

Mike theres basically a lot of uninformed applicators around. No offense guys but Ive seen it all and this doesnt surprise me. Im not here to educate necessarily but I know enough to know that the turf around here needs K anytime after November first. If these 70 degree temps continued Id cut back to a half pound of K per 1000 but....Yeah!

Still havent heard from Brian either.
 
#12 ·
The research has changed the best practice of mainaining cool season lawns when it comes to fall fertilization. It used to be beleived that we wanted to grow roots in the fall -- not top growth. And since we all remmeber the old adage from our turf 101 days -- (up-down-all around = N-P-K) then we must want a fert with high P and K.

However, what research has shown us is that in Fall -- a physiological change occurs in turf and the cool temps and short days signal the turf to begin storing carbohydrates. These carbohydrates come from nitrogen NOT P or K.

Also, in most soils with a CEC over 15 -- clay based soil -- then both P and K are very stable and exact timing is not overly critical. However, nitrogen leaches out very fast.

I personally use a high N all mineral product for my lawns. Most lawns receive 2.5# N from September 1 to Novemeber 30th.
 
#13 ·
LonniesLawns said:
The research has changed the best practice of mainaining cool season lawns when it comes to fall fertilization. It used to be beleived that we wanted to grow roots in the fall -- not top growth. And since we all remmeber the old adage from our turf 101 days -- (up-down-all around = N-P-K) then we must want a fert with high P and K.

However, what research has shown us is that in Fall -- a physiological change occurs in turf and the cool temps and short days signal the turf to begin storing carbohydrates. These carbohydrates come from nitrogen NOT P or K.

Also, in most soils with a CEC over 15 -- clay based soil -- then both P and K are very stable and exact timing is not overly critical. However, nitrogen leaches out very fast.

I personally use a high N all mineral product for my lawns. Most lawns receive 2.5# N from September 1 to Novemeber 30th.
Lonnie,

You obviously read the same material I do. I have been supply over half of my annual N in the 4th quarter of the turf season. I use 1/2 to 1.25lb total N coming out of spring based on split app of Pre-E. Light rate in the summer and pound the crap during the fall and winter..

Turf looks great...
 
#14 ·
LonniesLawns said:
The research has changed the best practice of mainaining cool season lawns when it comes to fall fertilization. It used to be beleived that we wanted to grow roots in the fall -- not top growth. And since we all remmeber the old adage from our turf 101 days -- (up-down-all around = N-P-K) then we must want a fert with high P and K.

However, what research has shown us is that in Fall -- a physiological change occurs in turf and the cool temps and short days signal the turf to begin storing carbohydrates. These carbohydrates come from nitrogen NOT P or K.

Also, in most soils with a CEC over 15 -- clay based soil -- then both P and K are very stable and exact timing is not overly critical. However, nitrogen leaches out very fast.

I personally use a high N all mineral product for my lawns. Most lawns receive 2.5# N from September 1 to Novemeber 30th.
Can't argue with research findings, but I have to wonder if this is a good practice for warm season grasses that go completely dormant during Winter.

This is really a matter of geography and climate zones. If the warm season grass stores a good amount of N, and then a warm spell occurs during Winter, the turf has fuel to break dormancy too soon. The result is new growth for a short time, followed by another cold weather pattern which can produce winterkill. This was a problem with some Zoysia lawns in Atlanta this year. I doubt those of you with cool season grasses would have any issues with that.
 
#16 ·
i'm glad i'm not the only one tht uses high N in the winter.. i was beging to think purdue university messed up on there recomendation, NOT. i guess it's prefferance, just like spraying for weeds in the fall, research shows it's the best time for spraying, but i don't see/hear it to often.
 
#17 ·
teeca said:
46-0-0 set at the 2.5# per 1k rate.. this helps build the carbs, great spring green up, and most of all..... a very large $$$ application.
This ^^^ is exactly what most do around here... Our soil tests generally show that we do not need any more P or K at all, but most of the year the fert blends just have it in there and you really can't find straight N products with any slow release in them unless you wanted to blend your own...

I have most of a pallet of Lesco 34-5-11 to use this late fall, if I run out I will use the 46-0-0 like always.
 
#18 ·
N N N N N......wow.

I still maintain that turfgrass at least here in Michigan only needs 2 lbs of N or so per year applied and you have to remember that with the advent of mulching mowers and such there is a lot of N being returned to the turf nowadays rather than bagged and removed.

Maybe some zones and turfgrasses need high N....but here with cool season grasses theres a lot of over fertilizing going on at least with Nitrogen.

Its my opinion that N is used to a large extent to cover up issues or compansate for poor mechanical practices etc.

Dont even get me started on phytotoxicity either because thats a major issue with ongoing chemical care.

Im not an environmentalist by any stretch of the imagination, but theres too much stuff being applied and a lot of snake oil being sold.

If people charged more for our expertise (those that have it) and credentials. Charged appropriate prices and had to make less visits to apply eronious applications that have no business being applied then wede all make more profit, have better turf, and be better off.
 
#20 ·
killswitch, i'm sure the grass in mich is the same here in indiana (grow up in lansing) except for a few dumb a** home owners that (try) grow zoyis grass here, it's ken blue, peren rye, and fescues. and from what research shows is that N is best applied in fall, and as far as top growth in the fall?? i've yet to see any of my lawns go thru a growth spert from a fall N application, they just maintain green longer, and green up faster in the spring, and no i haven't seen a growth spert in the spring (out of the norm anyway).
 
#21 ·
Jason Rose said:
This ^^^ is exactly what most do around here... Our soil tests generally show that we do not need any more P or K at all, but most of the year the fert blends just have it in there and you really can't find straight N products with any slow release in them unless you wanted to blend your own...

I have most of a pallet of Lesco 34-5-11 to use this late fall, if I run out I will use the 46-0-0 like always.
I guess you know Lesco sells straight PSCU. I got a pallet this fall for $15 per. (I'll take the sales when I can get'em :blush: ) Should work well in Ks.
 
#22 ·
Killswitch said:
N N N N N......wow.

I still maintain that grassy at least here in Michigan only needs 2 lbs of N or so per year applied and you have to remember that with the advent of mulching mowers and such there is a lot of N being returned to the turf nowadays rather than bagged and removed.

Killswitch,

Do you have any data on Nitrogen returned to to turf thru mulching. I'd be curious how much N is actually usable by the soils and remaining turf. I know the plant is mainly water that evaporates, but I have not seen a study on how much N is usable.
 
#23 ·
i got a calender from PBI gordon in the mail and on one of the turf facts it said that as much as 25% of N is lost thru clipings... weather it's true or not who knows... it's like budwiser doing a study that shows drinking 3 beer's a day makes you a healthier person:dizzy: (even though i already new this from personal research)
 
#24 ·
Mscotrid said:
Killswitch said:
N N N N N......wow.

I still maintain that grassy at least here in Michigan only needs 2 lbs of N or so per year applied and you have to remember that with the advent of mulching mowers and such there is a lot of N being returned to the turf nowadays rather than bagged and removed.

Killswitch,

Do you have any data on Nitrogen returned to to turf thru mulching. I'd be curious how much N is actually usable by the soils and remaining turf. I know the plant is mainly water that evaporates, but I have not seen a study on how much N is usable.
Ive heard varying claims and have no Data, but it only makes sense that a certain amout would be returned to the soil eventually.

Id consider it minimal at best especially sonce we have people appliying granular 46-0-0 in the fall after applying probably six 1 lb per 1000 applications of N in the growing season.

Are you guys located on sandy soil that leaches like crazy or what?

Im not opposed to new methods even though Im old school but so far no one has shown me any reliable data that you should blast a lawn with N in November.

Im sure we are dealing with a mix of some poorly trained applicators/ different climatic zones, and personal opinion here.

Honestly....I think Late fall feedings are basically snake oil anyhow.....much akin to fall Hort oil on trees.

This industry needs to get away from the Chemlawn esque routines....charge more for quality visits and make fewer of them. This isnt a fast food business like they want it to be and some of you are making it.

Several times a week as I work for other LCO's and TCO's I go home feeling guilty for ripping people off with snake oil apps.

I dunno how some of these people sleep at night.
 
#25 ·
Ive verified this story about carb storage and MSU says that the roots are still active in Late fall and possibly through winter.

But their reasoning for Late fall N apps is to get early spring green up and so that you CAN DELAY the first N application.

Thats a load if you ask me because everyones still out first thing as soon as possible loading the turf down with MORE N in spring.

I just dont see the benefit to blasting them with N all day.

If the roots are active like MSU says and I agree thats fine then hit em with some K so they can withstand this junk weather weve had at least here in MI.

Just a question. How much N are you guys tossing down per 1000 each year. 2 to 4 is adequate in my opinion for general bluegrass cool season turf.

I have a feeling some of you are up to 7 or 8 lbs.