Fertilome Classic Lawn Food With Slow Release Nitrogen Is A 16-0-8 Formula. Get a green turf with a minimum effort and expense. Contains Urea Formaldehyde, a source of nitrogen designed to feed for six to eight weeks. Contains Muriate of Potash, a natural source of potash for root growth. Contains trace elements including Boron, Copper, Iron and Zinc. Apply 6.5 lbs. Fertilome Classic per 1,000 sq. ft. of lawn. 20 Lb. bag covers average 5,000 sq. ft. lawn. If you are not using an organic fertilizer, you should be using this.