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Special Guest Sam Choan Discusses Fertilizer

For many homeowners who are new to lawn care, one important component that they tend to overlook is the nutritional balance of the ground soil. Like any other plant, grass requires the right balance of nutrients in the soil in order to thrive. The next time you pick up lawn fertilizer, you should notice three important percentages on the product labeling. Combined, these three figures represent the N-P-K ratio. Each symbol represents a specific nutrient and the ratio is there to help gardeners recognize the amount of nitrogen, phosphorus, and potassium in the fertilizer product. These numbers may seem somewhat intimidating at first. When do you know what ratio to use? Well, the following infographic by Organic Lesson should help you understand the basics of the N-P-K ratio. In the infographic, you can learn some basic rules on what ratio to use for specific stages of the lawn.


Nitrogen, phosphorus, and, potassium aren’t the only nutrients that are important for lawn grass but they all play an important role. Nitrogen’s primary role is to help produce lush, green leaves. Phosphorus is focused more on the downward growth and plays a part in helping the roots develop. Last but not least, potassium has an emphasis on the overall plant and is there to help the plants build resistance against diseases. These definitions should give you an idea of what ratio is better for what.

For example, if you are growing a new lawn from scratch then you want to put a greater emphasis on root development. The development of strong roots would then allow the lawn to thrive and stay healthy for the rest of the season. As we mentioned before, phosphorus is in charge of helping plants develop their roots so a fertilizer that contains a higher percentage of phosphorus should be what you are looking for.

On the other hand, if you have an established lawn that’s starting to become stressed or is picking up signs of diseases like dollar spots then the emphasis should be on potassium instead. Keep in mind that these rules should be absorbed in a very general sense and each lawn has to be considered from a case by case basis. If the appearance of your lawn is important to you then we always recommend you consult with a lawn care professional. Before you go ahead and spray any lawn fertilizer, be sure to conduct a soil test to determine what already exists within the soil.

-Sam Choan
Sam operates Organic Lesson – a blog dedicated to Online Gardening and Sustainability Resources.
Follow Sam on Twitter.