[kur1j]

So is there actually quality differences in fertilizers between brands? I get that the rates are different, slow release vs fast, etc. But is there a major difference in quality between brands? Is a bag of scott's from a big box store significantly worse then from a co-op of something like farmers favorite fertilizer brand?

 

[stotea]

In terms of quality of the actual N, P, or K, I don't think there really can be a different. However, some areas of potential variance include prill/granule size and shape consistency, quality and consistency of any coatings, amount of FM (foreign material), and any added ingredients.

For example, a cheap bag of urea I bought from a local feed mill has very inconsistent prillsize and shape, and there's a fair amount of FM (e.g., tiny pebbles). A more expensive product might be guaranteed to be free of FM and have a more consistent prill size.

 

[g-man]

It is the same question as generic vs brand name drugs. It is the same active ingredients but with different manufacturing steps and very different quality control.

 

[Green]

A lot of this is about the ingredients and technology used. For example, type of Nitrogen, Potassium, etc. Ammonium Sulfate versus urea is the major one for N. MOP versus SOP (K) is the second most common one.

Scotts actually has excellent products...very small prill size in their cool-season blends. Also, they use a lot of methylene urea, which is one of the best slow-release N sources for cool-season lawns because it relies on mostly microbial degradation and moisture level. For warm season lawns, they have other formulas that use Polymer coated urea (which is preferred for warm-season grasses because it breaks down faster in higher temperatures.

Try different types, read about them, and see how they work.