Lesson 6 : NPK Explained! December 18, 2015 Growing Tips First Watch : Teachings Of The Garden Sage Lesson 6 What did we learn? NPK is the elemental acronym for Nitrogen, Phosphorous and Potassium. The numbers on the front of plant fertilizer products are always stated in this order. These numbers represent the percentage by volume of the given element in the bottle. A liquid product you’ll find will almost always be a lower number than a solid product because the liquid product will have a limited solubility. NPK are termed mobile nutrients because they are transferred where they are needed within the plant, i.e. to new growth. Leave a Reply Cancel ReplyYou must be logged in to post a comment.