N P K – What does it mean when choosing a Fertilizer?
The three main nutrients that have been identified as absolutely necessary for plants are nitrogen (N), phosphorus (P) and potassium (K). These three are also known as macronutrients, and are the source of the three numbers commonly found on organic fertilizer labels.
Nitrogen (N) is responsible for above-ground vegetative growth of plants, and for overall size and vigor. It is probably best known for its ability to “green up” lawns. That’s because nitrogen is a major component of chlorophyll, the green substance in plants responsible for photosynthesis. Nitrogen can be added to your soil through composted manure, blood meal, canola meal, and fish powder. Too much nitrogen and your plants will grow extremely fast, resulting in long, spindly, weak shoots with dark green leaves. Too little nitrogen and your plants will slow or even stop their growth, and have leaves turning yellow and dropping sooner than they should. (more…)