Organic fertilizers are fertilizers that are derived from plant or animals by-products. Common sources include seaweed extract, bloodmeal, compost, humic acid, manure, fish meal, and bone meal. They generally come in liquid, granular or powder form.
What's so great about organic fertilizers?
Organic Fertilizers release nutrients to the lawn at a much slower rate than synthetic fertilizers. It takes time for organic matter to be broken down into a water-soluble form that lawn roots can absorb, resulting in even, predictable nutrient intake and growth. This gradual process lessens the risk of overfertilizing the lawn, and reduces the need for repeat fertilizer applications, which may be necessary with traditional fertilizers.
Also, organic fertilizers are beneficial to soil structure. Organic matter helps break up heavy clay soil so that air, moisture and nutrients reach lawn roots more easily, helping your lawn to "breathe and eat".