"Very generally used" but "not to be recommended"

It is a common practice of commercial fertilizer companies to mix fertilizing materials in different proportions with the view to selling them for special conditions. These ready-mixed fertilizers are extensively advertised … and the opinion seems to prevail in the minds of many that they are just what is required. While these mixed fertilizers are very generally used, they are not to be recommended. Commercial concerns possess no special information regarding the action of fertilizers on grass that an intelligent greenkeeper cannot soon acquire, and, therefore, there is nothing mysteriously beneficial in their formulas.

That’s a quotation from the Fertilizers chapter in Piper and Oakley’s Turf For Golf Courses (1917).

That “nothing mysteriously beneficial” phrase has stuck in my head for a long time, and it was on my mind recently as I was writing an article. I ended up not including anything about Piper or that quotation in the article, but I wanted to explain here why that was on my mind.

It’s important to apply just the right amount of nutrients to the grass, at just the right time, in order to achieve the desired results. Adding too little fertilizer is a problem. Adding too much is a problem too. The problem you run into with mixed fertilizers is they often contain elements you don’t want to be adding.

We are well aware of the problems associated with nutrient deficiency. Then there are problems such as favoring Poa annua invasion of creeping bentgrass by thoughtless application of P when the bentgrass doesn’t need it. There is the risk of increasing dollar spot or snow mold by adding K when it’s not needed.

Just as Piper and Oakley wrote in 1917, ready-mixed fertilizers are very generally used. But can you get better results by mixing your own, to ensure you only apply what your grass needs? You certainly want to be careful about what you are applying, and ensure that you only apply products that will have the desired action on the grass. I find it’s often easier to do that by avoiding pre-mixed products.