Each blade of grass in your yard is hard at work, keeping the plant alive. The green leaves busily manufacture sugar to provide energy, while the roots take in water and minerals needed to support various life processes. When you apply fertilizer to your lawn, you are helping to provide the mineral nutrients that plants need to survive, creating a healthy, lush lawn. At the same time, homeowners need to practice care when fertilizing their lawns.
Fertilizer provides the nutrients your lawn needs to stay healthy. This helps the grass to resist disease, pests and weeds, according to the University of Illinois Extension. The result is a lawn that is fuller, greener and untroubled by bare patches and weeds.
Your lawn's fertilizer needs depend on a lot of factors. Before selecting a fertilizer, have the soil tested to determine those needs. The soil test will include a fertilizer recommendation. Fertilizers contain three main nutrients that plants need in large quantities, called macronutrients: nitrogen, phosphorus and potassium. The soil test recommendation and fertilizer packaging will list the proportions of each of those nutrients. For example, a bag of 25-4-5 fertilizer contains 25 percent nitrogen, 4 percent phosphorus and 5 percent potassium. Overapplying a nutrient your lawn doesn't need not only wastes your money but could harm your local environment.
In additional to nutrient contents, fertilizers come in fast- and slow-release varieties. Fast-release varieties provide immediate results but also have a higher risk of dehydrating and "burning" your lawn, according to the University of Illinois Extension. On some soil types, fast-release fertilizers may leach into the groundwater. Slow-release fertilizers -- which include organic fertilizers -- provide long-term lawn care with reduced risk of burning. On clay soils, however, there is a higher risk of runoff.
Because excessive nitrogen can burn a lawn, application rates generally consider how much fertilizer to apply to achieve 1 lb. of nitrogen per 1,000 square feet, according to the Clemson Cooperative Extension. When applying fertilizer, follow the instructions on the packaging and do not exceed rates recommended by the manufacturer or your soil test. More fertilizer will not improve a lawn but can harm it.
Fertilizer can contaminate surface and ground waters and cause harm to the local environment, according to the University of Minnesota Extension. To prevent fertilizer pollution, water in fertilizer after applying it, but do not allow it to run off into the street. Clean up any fertilizer that lands on hard surfaces, like driveways and sidewalks, and avoid applying fertilizer where it can run off into a pond or stream.