F is for Fertilizer  on the A to Z Blogger Challenge - and Fertilizer means another three more letters, N-P-K. If you look at bags or bottles of fertilizer you will see three numbers on the label, like 5-10-5.  This is a statement about the ratio of the three major nutrients that plants need. N is for Nitrogen, P is for Phosphorus and K is for Potash (otherwise known as Potassium). Each of these elements is important for different…