Source(s): Gil Landry, PhD., Coordinator – UGA Center for Urban Agriculture, The University of Georgia.
Proper mowing of turgrasses is essential in order to produce an attractive, healthy lawn.
Proper mowing will have tremendous effect on the appearance of a lawn. Height of cut, frequency of cut and type of mower used are all important factors to consider when mowing a lawn. For the best appearance, a grass should be kept at its best height for growth.
Reel mowers are best suited for the hybrid bermudas and zoysiagrass. The other grasses can satisfactorily be cut with a rotary mower. Dull mower blades tear leaves instead of cutting them, thus producing a poor appearance and increasing the possibility of disease problems.
As a general rule, a grass should be mowed often enough so that you never remove more than 1/4-1/3 of the plant material. Example: If a bluegrass lawn is cut at a height of 2 inches, the grass should be cut when it reaches 3 inches. Removal of too much plant material can shock the grass.
The most damaging mowing practice is a sudden reduction in mowing height. This upsets the balance between the grass leaves and roots. It also gives a scalped appearance and usually injures the grass. If the grass becomes too tall between mowings, gradually reduce the cutting height until the recommended height is reached.
During stress periods, such as summer heat, it is a good idea to raise the height of cut slightly. This is especially helpful to the cool-season grasses because it reduces the stress on the grass. After the stress is gone, lower the height of cut gradually. Grasses in shaded areas should be cut higher than normally suggested for better growth. Raising the mowing height of warm-season grasses as fall approaches will help the grass survive the winter months.
If lawns are properly fertilized and mowed, grass clippings will not promote thatch accumulation. In fact returning the clippings to the soil will recycle plant nutrients and reduce fertilizer requirements. However, on high level maintenance lawns, such as hybrid bermuda and zoysiagrass lawns, clipping removal is advised, otherwise thatch will accumulate. This “thatch layer” (Figure 10) is an accumulation of dead plant material at the soil surface. It prevents penetration of water into the soil, harbors insects and disease organisms and leads to a shallow root grass which is heat, cold and drought susceptible. Many people like a dense soft mat of turf on their lawns, but this is usually a sign of excessive thatch and generally leads to problems.
Scalping or lowering the lawn mower cutting height and mowing the lawn in several directions just prior to spring “green-up” will help prevent thatch accumulation. The removal of this dead plant material will also encourage early spring growth. Centipede and St. Augustinegrass are spread by above ground runners or stolons, thus they should not be scalped as low as the other grasses or they may not recover. For more information on thatch refer to Cooperative Extension Service Leaflet No. 394, Thatch Control in Turf.
Mowing Height for Lawn Grasses in Georgia
Cutting Height (inches)
Resource(s): Lawns in Georgia
Center Publication Number: 132