Wise management of fertilizer saves money and the environment

By  Robert Dow

MSU Extension

Maximize your fertilizer investment and protect Michigan’s waters by only applying what you need.

Spring means fertilizer application time for many homeowners and turf management firms. Use the following to save money and protect the environment:

  • Wait for turf to grow (green-up)
  • Test soil to determine nutrient needs
  • Measure lawn area
  • Choose fertilizer that lists settings for your fertilizer spreader
  • Mow high (minimum of 3 inches)
  • Remove lawn mower bagging unit to let clippings go back onto lawn
  • Sweep fertilizer that lands on sidewalk or driveway back into the yard
  • Have a no-application buffer zone between your lawn and surface water

Applying fertilizer after the lawn is growing means the nutrients will be available to the grass rather than moved with rain past the root zone or as runoff before the grass begins to grow and use them. This means the dollars spent for fertilizer go to the lawn rather leach down to the groundwater or runoff to storm drains and surface water.

If the lawn’s soil has not been tested in the last three years, then don’t guess as to what nutrients are needed—test it. Your local Extension office sells soil test boxes. If the soil does not need phosphorus then select a fertilizer without phosphorus. This would be a fertilizer with 0 as the middle number (23-0-10). The first number is the percent nitrogen, the second number gives the percent phosphorus as P2O5 and the third number is the percent potash (potassium as K2O). Many soils in Michigan have adequate phosphorus and over-application may mean that the phosphorus ends up in our surface waters and causes algae and other plants to grow excessively degrading the waters.

Know the lawn area. This means measuring house, flower beds, driveway, sidewalk, etc. and subtracting these non-fertilized areas from the yard measurements or measuring the lawn areas only. Write it down so you can always refer to it. Knowing the area allows accurate selection of the size of fertilizer bag. This prevents over-fertilization or storing unused fertilizer which commonly gets hard and difficult to use. It prevents wasting money.

Look at the fertilizer bag before you purchase to see if your spreader and setting is listed. This information allows you to set your spreader for the intended application rate.

Set your lawn mower to cut high; three inches or higher is suggested. Remove only a third of the grass blade at a time. This allows the clippings to filter down through the canopy easier. It also makes for healthier grass. Scalping the lawn and then letting it get long and then cutting very short again is extremely stressful for the grass. Stress prevents healthy root establishment and makes the grass more vulnerable to pests, disease and drought. Mowing high also allows the grass to shade out annual weeds.

The lawn mower clippings should be returned to the lawn to recycle the nutrients back to the grass. Twenty five percent of the turf’s nitrogen needs can be provided in this way. This also saves money and provides for a healthier lawn.

For more lawn information, go to the MSU Turf Team or Turf Tips from the MSU Extension bookstore. Contact your local MSUE-Lake County 915 Michigan Ave. Baldwin MI 49304 or (231) 745-2732. Also, available by email at msue43@msu.edu.