As you may have noticed, fertilizers have 3 numbers on the container. These numbers refer to the percentage of nitrogen (N), phosphorous (P), and potassium (K) in the fertilizer. These 3 elements are referred to as macronutrients because plants need them in fairly large (i.e., macro) amounts to thrive; there are also micronutrients that plants need and soil pH can also affect how the nutrients are available to the plants. How these elements interact is complex but in general terms, nitrogen produces lush green growth, phosphorous helps strengthen stems and produce flowers (and eventually fruit), and potassium keeps the root system healthy. |