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 operates Organic Lesson - a blog dedicated to Online Gardening and Sustainability Resources.
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