If you’ve attempted to or even purchased lawn fertilizer you know how confusing the decision can be. The choices can be mind boggling without an understanding of what’s really necessary. The abbreviations and increments of each component in a fertilizer can leave the brightest gardener confused. Hopefully we can leave you with a better understanding and give you confidence in you fertilizer purchase.
The basic nutritional additives in a fertilizer come in three parts. The first part of that trinity is nitrogen. Nitrogen gives the plant its “greenness.” It is a part of the chlorophyll molecule. Good nitrogen levels help to maintain the plants overall health.
Phosphorus is a catalyst that helps the plant transfer energy from one part to another. This is a critical component in the metabolic process; the plants manufacturing of food, energy and storage. It is necessary for growth and root development.
Potassium is also a part of that metabolic process. It is also responsible for balancing water pressure in and around the cells of the plant.
Nitrogen comes in two forms; water soluble and insoluble. Water soluble is quick release and water insoluble is slow release. A good fertilizer will have each. Somewhere in the range of 30% to 50% insoluble or slow release is recommended. Slow release provides nitrogen over a period of time but is not available to the grass in cool weather. The soluble or quick release is available immediately and in cool weather.
Nitrogen, phosphorus and potassium will often be abbreviated “N. P. K.” after their symbols on the universal periodic table of the elements. Fertilizer packaging will state the percentages of N.P.K. by weight on a package in that exact order. This is the “grade” of fertilizer. So a 100 pound bag of fertilizer with N.P.K. grade of 10-5-5 will have 10 pounds of nitrogen, 5 pounds of phosphorus and 5 pounds of potassium. A simple equation says, a 100 lb bag x 10% nitrogen=10 lbs of nitrogen. 100 lb bag x 5% phosphorus = 5 lbs of phosphorus and so on. Any other fertilizer can be measured this way.
The amount of N.P.K. your particular grass will need varies during the growing season. You will require less in spring and more in fall.
We have posted a chart for Ohio, hardiness zones of 5-6, where Kentucky Blue grass, Rye grass, Fescue and Zoysia are predominant. See the “Fertilizing Lawns” page at The Little Green Apple dot com. This chart will assist in deciding fertilizer amounts for the months throughout the growing season. For the exact requirements for your specific grass and location call your local county extension office. They will have all the information you need. water soluble bag manufacturers