Mow High May, June and July
Sean Breckin, AOLCP

Spring is in full swing and turf grass is starting to pop. PJC Organic loves the moniker “Mow High May, June, and July”. We often discuss the value of cultural practices and how mowing can make or break a program. Years of research supports the notion of mowing high – typically a minimum of 2” for athletic fields, and 3” and above for a homeowner lawn.

There is a direct relationship between the top growth of the grass and the root growth of the grass. Meaning a lawn maintained at 3” has a more robust root system than one maintained at 1.5” or less. Spring is the time of year where the most top growth occurs, thus it is the best time of year to return clippings for precious organic matter. In addition, to keep shoot growth going upright, change directions each time you cut.

A 2011 study at Michigan State University found that maintaining a lawn at 3.5” increased root biomass so much that it was able to withstand grub damage without seeing any dead patches. Their research suggests that the grubs can’t consume more than 60% of the root mass which leaves plenty for the turf grass to continue to thrive.  Another major benefit of the added root biomass is the turfs’ ability to withstand drought. The greater the root mass, the more efficient the plant is in using water which requires less frequent irrigation and greater stretches between natural rainfall.

Mowing Height Prevents Weed Growth
Image Source: Michigan State University

After reading our blog on spring weeds, you’ll be happy to know that the high height of cut does a wonderful job of limiting seed to soil contact for undesirable weeds. In addition, height of cut also shades out newly germinating weeds. The vigorous growth of the grass crowds out newly germinating weeds. Only mow the top 1/3 of the plant and don’t take shortcuts if you need to lower height of cut for an athletic field or before an aeration and overseed.

Organic turf care is designed to keep toxic herbicides and pesticides off of lawns, out of waterways and keeping areas safe for families, athletes and pets. One of best ways to accomplish this is to “Mow High May, June and July”.







Research Sources: