Grass Clippings & Stormwater

When mowing your yard, make certain that you do not blow grass clippings into the street. When mowing, make the first few passes with the lawnmower blowing the grass clippings into the lawn not the street.  If there are grass clippings on the street or sidewalk, use a broom or leaf blower to blow them back into the lawn.  Do not use a hose to wash them into the street or storm drains.  

You should mow your lawn when the grass is dry, to avoid clumping.  Set the mower cutting height up to 2 to 2.5 inches to hide clippings better, and make a healthier lawn.  Try to remove only one-third of grass length per mowing.  If the grass is very overgrown, mow twice: first at a high setting, then wait a few days and mow lower.  Mow every five to seven days in the spring.  (Every two weeks may be enough in the summer.)  Sharpen mower blades twice a year.  

Keep your grass clippings on the lawn and not in the street or gutter. Remember, when you leave your grass clippings on the lawn, you add free fertilizer to your lawn.  According to the U.S. EPA, leaving your grass clippings on the lawn doesn’t cause thatch buildup.  Grass clippings are about 90 percent water, so they decompose very quickly.  Leaving your grass clippings on the lawn can reduce your lawn’s annual fertilizer needs, reduce your fertilizer costs and reduce water pollution.  

More information on stormwater best management practices is available at the Stormwater PA website.