Osmocote 16-8-12 contains the three most-important nutrients--nitrogen, phosphorous and potassium--that help a plant grow. The 16-8-12 stands for the percentage of the nutrients in the fertilizer. Osmocote also contains magnesium, sulfur, boron, iron, manganese and zinc, all minerals vital to plant growth.
About this Author
Aileen Clarkson has been an award-winning editor and reporter for more than 20 years, earning three awards from the Society of Professional Journalists. She has worked for several newspapers, including "The Washington Post" and "The Charlotte Observer." Clarkson earned a Bachelor of Arts in journalism from the University of Florida.