Most lawn grasses naturally grow and mature at a height higher than most of us find acceptable. Mowing reduces the plants ability to manufacture and store food reserves and can have an adverse effect on its ability to survive stress.

When part of the leaf is removed by mowing, the plants first priority becomes the reestablishment of its former leaf surface. Leaves take priority over roots, rhizomes, and food storage. Root growth is temporarily stopped after mowing. There is a direct relationship between cutting height and the total volume of root growth. The shorter the mowing height the shallower the root system.

Grass foliage helps keep the soil surface cool by shading the root system and soil. Mowing a cool-season lawn too low will slow its growth and increase heat and drought stress.

Mowing practices also can affect the occurrence of disease. Many times an increase in disease is observed when turf is cut too low. Mowing when the foliage is wet can spread disease.

Mow at the proper height for the type of grass you are growing. Mow fescue and bluegrass to a height 3 1/2 inches. Mow centipede and hybrid bermudagrass at 1 inch. Zoysiagrass should be mowed at 3/4 to 1 inch and St. Augustine at 2 to 3 inches.

The cleanest cut and best mowing are obtained when the mower blades are sharp. Dull mower blades reduce lawn quality by tearing instead of cleanly cutting the grass. Ragged leaf ends are easy points of entry for disease. Using a sharp mower is especially important for difficult to mow grasses such as zoysiagrass and bahiagrass. A properly sharpened and balanced mower blade will also reduce mower vibration, lengthen mower life, and reduce fuel consumption by as much as 20 percent.

No more than 1/3 of the leaf surface should be removed with each mowing. The frequency of mowing is governed by the desired grass height and by the amount of growth. Temperature, fertility, moisture conditions, season, and the natural growth rate of the grass affect how often you need to mow.

Most homeowners bag lawn clippings because they think that the clippings add to the buildup of thatch. This is not true. Frequent mowing, mowing when the grass is dry, and proper fertilization are the best ways to prevent excess thatch buildup.

Clippings that remain on the lawn quickly decompose and release valuable nutrients. Fertilizer needs can be reduced by 20 to 30 percent if the clippings are left on the lawn. The shorter the clippings, the deeper they fall into the turf. Mulching mower and/or frequent mowing produce the smallest clippings.

Consumer Horticulture | Quick Reference

© Erv Evans, Consumer Horticulturalist
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