# Need a lot of P and K



## Big Boy Stan (Aug 27, 2020)

I am starting to rebuild a 2nd house lawn that has had almost no attention in many years. I just received my soil report back and it is recommending a fertilizer with a 1-4-3 ratio. I cant find any big bag stuff that is even close to that. Can any help me understand how to buy or build a fertilizer with those ratios.

Thanks


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## Robs92k (May 9, 2021)

You might have a hard time finding what you need in that specific ratio. Coops will sometimes mix for you, but that might not be available in your area. *check the hometown folders for suppliers in your area.

You'd likely find it easier to separate or find a fert that has your N and P ratios, then do a separate amendment for potash…there are a few different options or combinations you could use. I think you'll likely need to start with a fert that has a mix as P is one of the more regulated chems…particularly on the east coast.

Maybe start with a balanced fert or something high in P, lower in K. N isn't static, so you shouldn't need to restrict other than keeping it at <.5#/ ksqft per app if using a FAST N source (AMS/ Urea) and water in.

I'm sure there are others with a bit more knowledge here. Hope this helps.

*also check out the soil amendments section…really good info there!


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## superkaz661 (Apr 19, 2019)

I know that we all want to be in the "ideal" range immediately, but if you can afford a little patience, you can get where you want by using a starter fert (unless prohibited by your locality) for all your yearly apps. Nitrogen is very transient, P and K are less so.

Turf grass can thrive in a wide range of soil conditions. In fact, you'd be amazed by the quality of some lawns growing in very "poor" soil. Yes, aim to correct your levels, but remember that this isnt an all or nothing game.

All that said, if you insist on correcting your P and K values sooner, you can look in to triple (super) phos, and SOP (sulfate of potash) to run as adjuncts to your regular fert program. Since your lawn is relatively small, the cost wont be prohibitive.


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## jha4aamu (Oct 16, 2017)

Big Boy Stan said:


> I am starting to rebuild a 2nd house lawn that has had almost no attention in many years. I just received my soil report back and it is recommending a fertilizer with a 1-4-3 ratio. I cant find any big bag stuff that is even close to that. Can any help me understand how to buy or build a fertilizer with those ratios.
> 
> Thanks


Siteone carries a 2-4-3 organic fert in 50lb bags
https://www.siteone.com/en/hghx243-organic-fertilizer-2-4-3-50-lb-bag/p/615490


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## Big Boy Stan (Aug 27, 2020)

The lawn is currently 90% weeds so I am planning to roundup the entire lawn this weekend, let it farrow for a week, roundup again on 9/11 and then rake and put down new seed. I'll apply 4#/1000 Scotts starter with weed block (21-22-4) at seed down and another 4#/1000 at 30 DAG.

That wont do much for the K. Should I put down SOP during germination/young grass or wait till spring? Or perhaps put down some SOP with the first roundup?

Thoughts? And thanks for all the help.


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## Big Boy Stan (Aug 27, 2020)

The lawn is currently 90% weeds so I am planning to roundup the entire lawn this weekend, let it farrow for a week, roundup again on 9/11 and then rake and put down new seed. I'll apply 4#/1000 Scotts starter with weed block (21-22-4) at seed down and another 4#/1000 at 30 DAG.

That wont do much for the K. Should I put down SOP during germination/young grass or wait till spring? Or perhaps put down some SOP with the first roundup?

Thoughts? And thanks for all the help.


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## jha4aamu (Oct 16, 2017)

Big Boy Stan said:


> The lawn is currently 90% weeds so I am planning to roundup the entire lawn this weekend, let it farrow for a week, roundup again on 9/11 and then rake and put down new seed. I'll apply 4#/1000 Scotts starter with weed block (21-22-4) at seed down and another 4#/1000 at 30 DAG.
> 
> That wont do much for the K. Should I put down SOP during germination/young grass or wait till spring? Or perhaps put down some SOP with the first roundup?
> 
> Thoughts? And thanks for all the help.


I generally use a 0-52-34 fert for any P or K deficiencies/corrections. And AS for a N source. On my newly seeded reno, I want fast release N in small amounts weekly. The K and P ~1lb/mo.


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## robjak (Mar 31, 2020)

You could use a balanced fertilizer say an 18-18-18 at 5Lb per 1000sqft for the next few cycles until you catch up. That would give you 1lb N-P-K per month. easy and cheap.


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## M32075 (May 9, 2019)

robjak said:


> You could use a balanced fertilizer say an 18-18-18 at 5Lb per 1000sqft for the next few cycles until you catch up. That would give you 1lb N-P-K per month. easy and cheap.


I like that idea even a cheap 10/10/10


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## r7k (Jan 25, 2019)

I was in the same boat as you,
when I found 10-10-10 at walmart for less than $10 a bag, I got a few and had very good results when I started getting serious of doing my lawn.

I have since upgraded to buying 19-19-19 and 0-0-50 from a SiteOne that's in my area, I think Lesco brand but don't quote me on that.

It's not something you are going to correct in 1 or 2 applications,
and you'll mostly be limited by the amount of nitrogen you can put down at a given time.... 1 lb of N per 1k sqft.
The P and K will work itself back into normal range over time, easily and naturally.
the "apply 10 tons of 0-40-0 rock phosphate" that they like to write in the recommendation section of the soil test reports... :roll:

the other option that will also work is using starter fertilizer.


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## Lawn Whisperer (Feb 15, 2021)

Big Boy Stan said:


> … I'll apply 4#/1000 Scotts starter with weed block (21-22-4) at seed down and another 4#/1000 at 30 DAG.
> 
> That wont do much for the K. Should I put down SOP during germination/young grass or wait till spring? Or perhaps put down some SOP with the first roundup?


I think I know your intention. The weed block active ingredient (AI) in the Scotts starter with weed block (21-22-4) is mesotrione, which is the same AI as Tenacity.

Yes, you can apply SOP to supplement the lack of potassium in the fertilizer you will be using at seed down. Actually, you can apply the SOP now in order for it to work it's way down to the soil. Just keep in mind that too much potassium in the soil during prolonged snow cover during winter has been know to cause snow mold. IMO, you should do one round of SOP, 2#/M to get your lawn closer to optimum K levels. Then you can resume K applications in spring.

Additionally, mesotrione only provides ~30 days of pre-emergent. If you plan on using the 2nd round of fertilizer 30 DAG, you'll have a gap without pre-emergent coverage, but since it also has post emergent effectiveness then you might be able to minimize the weeds.

Sounds like a good plan for granular application. :thumbup:


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## Lawn Noob (Jul 26, 2020)

Throw the cheapest 10-10-10 you can find.


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