18 April 2010. Applied Turfgrass Science.
When Mowing Lawns, Length is Important
Source: University of Missouri Press Release. extension.missouri.edu
Columbia, Missouri (April 15, 2010)–When it comes to mowing your lawn, don’t overdo it.
“Mowing your lawn too short can lead to much lawn deterioration,” said Brad Fresenburg, University of Missouri Extension turf scientist. “Very simply, mowing height and frequency directly affect the performance and appearance of your lawn.”
Mowing grasses too low places the turf under stress. The resulting turf requires more water and is thin, weak and highly susceptible to weed invasion, Fresenburg said. Weeds germinate rapidly when the turf is scalped by mowing too short and too infrequently. Grass maintained at a taller height produces deeper roots that can reach more available water.
Proper mowing begins with choosing the correct height for your grass species, he said.
Cool-season grasses such as bluegrass, tall fescue and perennial ryegrasses are generally mowed at 2.5 to 4 inches.
Mow warm-season grasses such as zoysiagrass at 1.5 to 2.5 inches. In spring before green up, mow warm-season grasses at a low setting on your mower. This removes dead leaf and stem tissue from the lawn.
Leave warm-season grasses tall in the fall. Raising your mower throughout the growing season will result in a thick, vigorous turf, he said. By September you should be mowing at 2 to 2.5 inches.
Mow grass according to the “one-third rule,” Fresenburg said. This means mowing when the grass has grown one-third taller than the desired height.
Many homeowners believe they have to remove grass clippings to have a healthy lawn. When mowed regularly, however, clippings filter down through the grass, decompose rapidly and recycle nutrients back into the soil, he said.
Clippings should be uniformly distributed rather than deposited in clumps. Mowing the lawn when it is dry and using a properly sharpened mower blade will spread the clippings evenly.
Mulching mowers do an excellent job of working grass clippings into the canopy of the lawn. Their blade design chops clippings and speeds their decomposition.
For more information, contact your local MU Extension center or see extension.missouri.edu.