Mowing is the one activity that we perform on our lawn more than anything else, yet it is most often done with lack of attention to cutting height, regularity, leaf wetness, or sharpness of blade. Any of these factors could cause undue turf stress and provide less than desired results.
Every turf species has an optimum mowing height and any extremes from this could cause scalping, turf thinning, and even loss of the lawn. Shade intolerant species like bermudagrass, when maintained at a mowing height greater than two inches, will begin to drop lower leaves from shading by the canopy. This often creates a scalped appearance just after mowing when the top canopy is removed and exposes the brown leafless stolons.
In contrast, a St. Augustine lawn cut less than two inches in height may become wear stressed and lose turf density due to exposed stolons and reduced leaf area. Cutting heights for our warm season turf species should be within the following ranges: bermudagrass 0.5-1.5 inches; zoysia 1.0-2.0; carpetgrass 1.5-2.0 inches; centipede 1.5-2.0 inches; and St. Augustine 2.5-3.0 inches.
Regardless of the turf species, mowing regularity should follow the one-third rule. This means never remove more than one-third of the total turf height at a single mowing. Therefore, depending on the rate of growth and the desired maximum turf height, this could require mowing several times a week for a hybrid bermudagrass lawn or perhaps as little as once every two weeks for a centipede lawn under low water and fertility management.
With irregular and improper mowing, excess leaf clippings collect on the turf canopy. This shades the turf, increases disease and insect incidences, and creates excess thatch. When the one-third rule is followed leaf clippings will fall into the canopy of the turf and decompose rather quickly.
Blade sharpness greatly affects the quality of cut and aesthetic appearance of the turf. A dull mower blade will tear rather than cut leaving leaf tips split, ragged and brown. It is best to avoid cutting the lawn when there is leaf wetness from rain or heavy dew for worker safety as well as to reduce turf disease pressure.
Published May 17, 2010
Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu