We All Hold the Key To Clean Water

Lawn & Garden Best Management Practices


Here are some suggestions from the University of Nebraska Cooperative Extension for fertilizing lawns to protect water quality:

  • Apply the right amount: Apply fertilizers at rates and times that meet, but do not exceed, the nutritional needs of the turf. Since grass regularly loses its leaves to mowing, it needs a high nitrogen fertilizer such as 25-6-4 (percentages of nitrogen, phosphorous, and potassium, respectively). Use lower nitrogen levels on turfs grown in clay soils, shaded sites, unirrigated areas, or areas where a mulching mower is used. Use higher nitrogen levels on sandy soils, frequently irrigated turfs, and intensively used sites where grass clippings are removed.
  • Split applications: An average lawn needs 3 to 4 pounds of nitrogen per 1,000 square feet each year. The nitrogen should be applied in 1-pound applications three to four times per year: the main feeding in early autumn, a booster just before winter, and a light feeding in mid-spring. (A light feeding in June also is an option.) In the fall, a higher phosphorous formulation will help the roots. A bag of 25-6-4 contains 25 percent nitrogen or 5 pounds. For a 5,000-square-foot lawn, this bag would provide 1 pound per 1,000 square feet.
  • Follow directions: Proper fertilizer application is crucial to prevent groundwater and surface water pollution, both in town and rural areas. Always read and follow label directions.

Additional Information

To speak with someone regarding proper lawn & garden fertilization, contact the Cooperative Extension or your local lawn and garden center.

Online Resources

More Lawn & Garden Best Management Practices

Developed for the Dutch Flats Groundwater Quality Project. The project is partially funded by a Section 319 Clean Water Grant from the U.S. Environmental Protection Agency through the Nebraska Department of Environmental Quality.