# Granule vs Liquid Lawn Fertilizers



## UltimateLawn (Sep 25, 2020)

I recently purchased a backpack sprayer and I'm looking to up my game on lawn fertilizers by shifting from granules to liquid. I've done what I think is the correct calculations an I'm finding liquid fertilizers (Nitrogen-Phosphate-Potash) quite a bit more expensive than granules.

Here is my calculation and comparison approach...

Using Nitrogen as an example fertilizer component, it is easy to calculate weight of nitrogen in a 40 lb bag if the nitrogen level is 20%, that totals up to 8lbs or 8x16= 128oz by weight of Nitrogen. If my target is 16 ounces (1 pound) per 1,000 ft2 then I need 16/128 or 12.5% of the full bag's Nitrogen. Therefore I need 12.5% of 40lbs = 5 lbs of fertilizer dropped across the 1,000 ft2.

If I'm looking for Nitrogen in liquid form it is a similar calculation, albeit I have to weigh the liquid. Most of the fertilizer liquids also give you total weight. Typically this seems to be around 10lbs per gallon. So in an equivalent 10lb gallon jug of liquid fertilizer at a 20% Nitrogen level, I'm only getting 32 oz by weight of Nitrogen.

So if the 40 lb bag of granules is the same price as 1 gallon of liquid fertilizer at 20% - which is typically the case, I get 4 times as much Nitrogen in the granules bag then I do in the liquid gallon.

This suggests that you should NEVER do liquid fertilizer (nitrogen, phosphate and potash) and stick with granules for these. Then use the backpack sprayer only for additives/treatment including herbicides, insecticides, fungicides, and organic supplements.

Sound about right? Have others come to this conclusion as well?


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## CarolinaCuttin (Sep 6, 2019)

@UltimateLawn A lot of people take the granules and dissolve them for a spray, especially urea and AMS.

The full benefits of spraying are not realized just with NPK fertilizers. If all you are doing is NPK, don't worry about spraying, you'll be better off with a granular.

However, in one tank mix, I can apply a pesticide, wetting agent, growth regulator, micronutrients, biostimulants AND traditional NPK nutrition. There is certainly no need to spray to have a great lawn, but for those of us that apply PGRs during the growing season, we are already out there every 10-14 days applying PGRs, so we can easily apply enough nitrogen at the same time as those sprays if we're out there 2-3 times per month to take care of all the nutritional needs. Additionally, micronutrients are much better as a spray than granular, so that can be taken care of as well.


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## Greendoc (Mar 24, 2018)

I come to the totally opposite conclusion. Applying lbs of Nitrogen at a time is contrary to wise use of fertilizers especially on warm season grasses that does not need very much at one time. Not even for St Augustine grass. Typical application rates of fertilizer applied as a liquid are often no more than 0.1-0.2 lb at a time. If that amount of nutrients does not give you a response, the issue is not the quantity of nutrients rather other issues such as soil pH, inferior cultivars of grass, shade, lack of water, nematodes, etc. Applying lbs of nutrients per 1000 sq ft while not addressing the above issues is poor management.


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## Gilley11 (Nov 3, 2019)

@UltimateLawn if you buy the liquid ferts already dissolved you will spend a lot more money than granular. Look into the soluble 20-20-20 products, that's what I've been using and they are great! Peter's or Grow More are both great choices and are about $50/25lb.


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## jayhawk (Apr 18, 2017)

Assumed liquid is more cost effective. Never done the math....

+Odd shaped plot. 
+Flexibility in ratios

I swear I read there was reasons behind one or the other (optimally) based on soil analysis but can't recall details


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## Gilley11 (Nov 3, 2019)

You don't have to put down as much liquid as you do granular and it's more evenly portioned out.


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## dman (Nov 5, 2019)

Why does it have to be "VS"?.....just use both.


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## Gilley11 (Nov 3, 2019)

dman said:


> Why does it have to be "VS"?.....just use both.


What do you mean?


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## Redtwin (Feb 9, 2019)

For those with very dense low canopies, liquid is really the only way to go as the granules will sit on top of the canopy. The greens grade granules can really get expensive. With Saint Augustine, that is usually not a problem but if you take advantage of those wide, long, leaf blades, foliar spraying seems to be the way to go. As mentioned above, I would also buy and mix your own. Why pay for water?

Also, 1-pound of nitrogen/1000sf is a lot. Foliar apps are typically .25lbN/1000sf or even less. I can tell you from experience that .5lbN/1000sf of AS put down as a foliar app will burn.


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## Darth_V8r (Jul 18, 2019)

Greendoc said:


> I come to the totally opposite conclusion. Applying lbs of Nitrogen at a time is contrary to wise use of fertilizers especially on warm season grasses that does not need very much at one time. Not even for St Augustine grass. Typical application rates of fertilizer applied as a liquid are often no more than 0.1-0.2 lb at a time. If that amount of nutrients does not give you a response, the issue is not the quantity of nutrients rather other issues such as soil pH, inferior cultivars of grass, shade, lack of water, nematodes, etc. Applying lbs of nutrients per 1000 sq ft while not addressing the above issues is poor management.


I have learned so much from your posts. Thank you so much for sharing what you know.


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## UltimateLawn (Sep 25, 2020)

Redtwin said:


> Also, 1-pound of nitrogen/1000sf is a lot. Foliar apps are typically .25lbN/1000sf or even less. I can tell you from experience that .5lbN/1000sf of _AS_ put down as a foliar app will burn.


I hope this isn't too newbie of a question, but what is 'AS' as you mention in the second sentence?

I've always followed a liquid fertilizer regimen in my shrub and flower beds with good results. I figured it would help to also do foliar applications on my St. Aug. Can I just do the foliar applications, or maybe it is better to alternate with an organic granule fertilizer (Milorganite) and then do foiliar applications with other micronutrients on an alternating schedule (every 2 weeks for each?).


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## Cherokee_Bermuda (May 10, 2019)

AS = ammonium sulfate 21-0-0


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## dman (Nov 5, 2019)

Gilley11 said:


> dman said:
> 
> 
> > Why does it have to be "VS"?.....just use both.
> ...


Liquid and granular ferts have their place. For "pounds on the ground" use a granular. For supplemental feeding use liquid. For time released use granular. For more of a quicker response use liquid.....so forth and so on.


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## Wfrobinette (Feb 3, 2019)

Gilley11 said:


> @UltimateLawn if you buy the liquid ferts already dissolved you will spend a lot more money than granular. Look into the soluble 20-20-20 products, that's what I've been using and they are great! Peter's or Grow More are both great choices and are about $50/25lb.


Where do you get those locally in CLT?


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## Gilley11 (Nov 3, 2019)

Wfrobinette said:


> Where do you get those locally in CLT?


I don't know if they are available locally. SiteOne sells a soluble triple 20 but it costs $25 more and it doesn't dissolve as easily. I order it from Amazon: https://www.amazon.com/gp/aw/d/B00S7IM3UC?psc=1&ref=ppx_pop_mob_b_asin_title


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