Sandy soil presents some challenges when it comes to establishing a lawn. Water drains away quickly, as does anything that dissolves in water. Sandy soil lawns need more frequent fertilization, in smaller quantity, than denser, clay-based soils. Fertilizing with products that won't leach away and those that improve soil structure contribute to a beautiful, healthy lawn.
While not strictly a "fertilizer," nothing will improve a sandy-soil lawn more than the incorporation of compost into the soil, according to the Washington State University Extension Service. It will help sandy soil hold on to both nutrients and water. Core aeration followed by topdressing the lawn with 1/4 inch of compost annually will improve soil structure and reduce thatch, according to the Ohio State University Extension Service. Many municipalities now compost yard waste and leaf litter and sell it in bulk for this application.
Synthetic Slow-Release Fertilizer
Through various chemical and physical methods, fertilizer manufacturers offer products where the nitrogen (the element most essential to a beautiful lawn) is bound in the product and releases gradually over time. This feature is of the utmost importance in sandy soil. Normal synthetic fertilizers, which are water soluble, will quite literally wash away, robbing you of your beautiful lawn and fouling the watershed at the same time. The University of Florida recommends application of 1 lb. of nitrogen per 1,000 square feet for fertilizers containing 30 percent or higher slow-release nitrogen and 1/2 lb. per 1,000 square feet if it contains less than 30 percent slow release nitrogen.
Organic fertilizers are slow-release and water-insoluble by nature, making them an excellent option for sandy soil. They do not provide the immediate results you can obtain with synthetic fertilizer, but their effect is longer lived and more environmentally friendly, according to Ohio State University. Organics add micronutrients to the soil in addition to nitrogen, phosphorus and potassium. They contribute to soil health, not just plant growth. Compared to synthetic fertilizers, organic fertilizers are bulky, and require more product be applied to achieve the same input levels of the main nutrients.