What Does Each Main Ingredient in Fertilizer Do to Plants?


Synthetic fertilizers contain chemical ingredients that improve plant growth and boost flower or fruit production. While most fertilizers contain the same basic ingredients, formulations will vary depending on the plant the product was designed to feed.


Fertilizer packages use a series of three numbers to identify the percentage of each main ingredient, always in the order nitrogen-phosphorus-potassium; a 5-10-10 fertilizer contains 5 percent nitrogen, 10 percent phosphorus and 10 percent potassium.


Nitrogen is important for stem growth and green, healthy leaves; too little nitrogen can result in yellowed plants and stunted growth.


Phosphorus is required for photosynthesis and helps the plant develop a strong root system as well as healthy flowers and fruit. Insufficient levels of phosphorus can reduce flower production or slow the plant's growth.


Potassium helps regulate water levels inside plants and affects the size and color of flowers. Without enough potassium plant leaves may curl, develop spots or take on a burned look.

Other Nutrients

Fertilizers may also contain smaller amounts of calcium, magnesium and sulfur which the plant uses to make chlorophyll, grow cells and regulate enzyme function, according to First Rays.


  • First Rays
  • The Fertilizer Institute
  • The Garden Helper
Keywords: components of fertilizer, purpose of fertilizer ingredients, how a plant uses fertilizer ingredients

About this Author

Kristen Fisher is a freelance writer and editor with professional experience in both print and online media. She graduated from the University of Arizona with a degree in Psychology. Kristen has published articles on a wide variety of topics including health, fitness, nutrition, home, and food. She has been published in "Connections Magazine" and on Lifescript.com and is a regular contributor to eHow.