Fertilizer - the backstory

 Or Fertilizer – Reality versus Marketing.
Us plant people have a unique talent of turning the simplest of tasks into a complicated fiasco. Like composting: if you throw a banana peel out your window, within a few months it has rotted down to a teaspoonful of, well, rotten banana peel. Compost to be more precise. That’s how easy it is! Yet we have made it so complex that there is a Composting for Dummies book.
 
Fertilization is another area where us plant people have seemed to have conspired to make everyone else thing they need at least a Bachelor’s Degree in Agronomy in order to feed your plants. We feed (pun intended) you lots of information about pH, timing, fertilizer formulas, and all that happy hooey. If you make it through that, when you go to the store there is a Wall of Fertilizer to conquer. Fertilizer for azaleas. A different fertilizer for tomatoes. One for trees and another for non-tomato veggies. It is nearly endless.
 
Why so many choices you might ask? It all comes down to marketing. Each brand wants to take up as many feet of shelf space as it can at each store. That leaves fewer feet of shelf for their competitors’ fertilizers. It also means a larger starting order from each retailer.  Does it make any meaningful difference to you? Other than how much money goes missing out of your pocket, no!
 
You may think I have lost it, yet again. Clearly there must be a difference between each fertilizer. The numbers on the bag look a lot different. Let me give you a quick primer on fertilizer and plant nutrition to illustrate my point. There are three main nutrients in a bag of fertilizer Nitrogen (N), Phosphorus (P) and Potassium (K, since P was already taken).
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Nitrogen provides for the plant to be able to grow green parts; leaves and stems in large part.
Phosphorus is needed for root development.
Potassium is needed for cell walls. (Which provides a number of benefits to the plant.)
Other nutrients are also needed but these are the ones needed in the largest amounts, and also the ones most likely to be limiting.  ​

The barrel illustration shows far better than I can describe how the plant needs each of the labeled ingredients. As it is shown the Moisture is the most limiting at that point in time.  Let’s say you watered it, the next most limiting ingredient is Nitrogen. If you were to then fertilize with Nitrogen only, the plant would grow more. But only to the time that Phosphorus then became the limiting factor. And so on…
 
Back to the fertilizer. We know generally the proportions that plants need nutrients in. Each plant and location can be different in their needs. SLIGHTLY. We sell Plant-O-Ganic 8-8-8 fertilizer for outdoor plants in the ground. We also have a couple of different other fertilizers for unique situations. And one more kind that we will be carrying next year which incorporates some unique soil health additives. But 99% of what we sell is Plant-O-Ganic. It was developed by the Massachusetts Nursery and Landscape Association for Massachusetts conditions. You don’t need to worry or wonder. Follow the flow chart below:
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There is one other part of a fertilizer formulation that is very important. That is the speed of release. Primarily a consideration only with the Nitrogen component. Nitrogen can release very quickly, or very slowly.

Quick release Nitrogen is great if you need fast results. A football stadium that needs to green up their grass quickly before a televised game they weren’t expecting to host. In a week the grass will look great! But in a few weeks, it will be hungry all over again. Because it is so quick release, it can also “burn” a lot more. A LOT more. Fertilizer burn is when there is so much fertilizer in the soil that the plant roots cannot take in water, and the plants die. Think back to high school biology and the boring lectures on osmosis and diffusion as to why.

Slow release Nitrogen is the tortoise. Slow and steady that wins the race. It doesn’t seek the spotlight. It isn’t flashy. It just does its job. And since it does its job, your job is easier. You only need to apply it twice a year. When the kids get candy, Halloween and Easter, feed your plants. It has very little potential to burn plants.

After reading the differences you are likely wondering why anyone would want to buy quick release fertilizer. Well it’s all about the dollar. Quick release is cheaper to make. As fertilizers have become more available in chain stores, those stores have pushed the manufacturers for a less expensive product. The manufacturers can only make less expensive with cheaper ingredients. That’s basically the only reason that quick release exists in today’s market. 50 years ago, some quick release had a place where folks had time to fertilize every week or two, but today, we are lucky to be able to get to it twice a year.