One of the most important components to understanding soil health – and how to fertilize – is familiarity with the N-P-K ratio.
Found on fertilizer bags, N-P-K stands for nitrogen (N), phosphorus (P), and potassium (K). These three nutrients — while by no means the only three — are the most important nutrients when it comes to plant life. An ideal soil N-P-K ratio will vary based on the type of plant you are growing and what you value (like root growth, blossoming, etc.).
For example a bag of lawn fertilizer could read 22-2-8. The instructions on this hypothetical bag of fertilizer could read “apply at a rate of 4.5 pounds per 1,000 square feet.” The rate of application (4.5 pounds) is acquired by dividing 100 by 22 (the amount of N in the fertilizer).
The best way to obtain an ideal N-P-K is by testing your soil and amending it with fertilizer so your plant remains happy throughout its growing season. Periodic testing for both soil pH and N-P-K will pay huge dividends in the long run and are available online or through your local extension office. Once you know what kind of soil you have, you can figure out if you need to help it along in any way. Having the right soil pH means plants can take up nutrients more readily. Using N-P-K effectively means you’re giving your soil what it needs to produce the results you want.
Need an easy way to remember what NPK refers to? Here’s a handy quote: “Up, down, all around.” Nitrogen (N) for plant, foliage and stem growth (is the UP); Phosphorous (P) for root development and blooming (is the DOWN); Potassium (K) for ALL AROUND plant growth and blooming! Finding a fertilizer with the right component for you, is as easy as knowing the “up, down, all around.”