K-8 is a 15-5-10 blend with six added nutrients (magnesium, sulfur, copper, iron, manganese, and zinc) that is perfect for St. Augustine, Bermuda, Blue Grass, Buffalo, and other lawn grasses. Research has shown that using sulfur, iron, and zinc on a well-fertilized lawn can reduce the amount of nitrogen needed to maintain green grass by 10 to 15 percent. And even though this is a lawn fertilizer, K-8 can also be used on gardens, trees, shrubs, and flower beds.