Proper fertilization is important for a healthy lawn. When fertilizer is put down at the right time and in the right way, it strengthens lawns. A healthy lawn protects water by holding soil and pollutants and minimizing the need for pesticides.

Improper fertilization (e.g., leaving fertilizer on paved surfaces, using improper type, applying on frozen ground) harms our water. Improper fertilization causes it to get into storm drains in streets, which empty into lakes and rivers. Fertilizer in lakes and rivers causes algae to grow, which uses oxygen that fish need.

Here are some simple steps you can take to help keep our water clean. A few simple changes can make a big difference! Plus, you’ll save time and money in the process.
Photo Courtesy of Washington State
Water Quality Consortium 
  • Fertilize in the fall. Want a vibrant spring lawn? Fertilize in the fall. Fall is the best time for plants to absorb nutrients and develop a strong root system.
  • Be patient in the spring. No need to hurry – fertilizer you put down in the fall is at work. Wait until the second mowing before adding fertilizer. Then you can be sure the ground isn’t frozen and the grass can properly use the fertilizer.
  • Keep it on the lawn. Keep fertilizer on the lawn. If you do get it on the pavement, sweep it back onto the lawn.
  • Use a "phosphorus free" fertilizer. The State of Wisconsin has banned the use of fertilizers that contain phosphorus on lawns or turf unless the fertilizer application qualifies under certain exemptions. The middle number on the fertilizer bag should be a zero (for example 10-0-10).
  • Follow directions. Use a spreader and follow directions. This ensures that the right amount of fertilizer is being used.
  • Mow high and return clippings. Make your lawn care cheaper and easier by mowing high (3 inches) and leaving the clippings for nutrients. A tall lawn promotes root growth and shades out weeds.
  • Make fertilizer-free zones. Keep distance between fertilizer and areas such as rivers, lakes, or storm drains. This will protect these areas from unnecessary fertilizer.