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SFMA BMPS > Cultural Practices: Mowing

Mowing is the most basic and perhaps the most important cultural practice of managed natural grass systems. Mowing practices impact turfgrass quality and playability, as well as turfgrass density, texture, root development, and wear tolerance. Failure to mow properly results in weakened plants with poor density and quality, resulting in fields that offer poor play and can be unsafe.

An appropriate mowing protocol is determined based on the intended use of the site, the sport, the cultivar being managed, and the maintenance program. Other factors that influence the mowing program, such as mowing frequency, include the height of the cut (HOC), equipment, time of year, root growth, and abiotic and biotic stress.

Mowing influences shoot density, tillering, lateral growth of rhizomes and stolons, and root growth. Mowing practices must balance these physiological responses, enabling quick turfgrass recovery through decisions related to HOC, frequency, and mowing patterns. Frequent mowing increases tillering and shoot density but can decrease lateral stem and root growth if done improperly. Infrequent mowing may cause the removal of too much of the plant at one time, which can deplete the plant’s food reserves and lead to scalping injury. Proper equipment maintenance is also key to maintaining healthy turfgrass, as cutting units require sharp blades and consistent reel-to-bedknife (light) contact to reduce the risk of creating wounds that can favor microbial infection and dissemination of pathogens.

Mowing heights vary based on several factors:

• Turfgrass species and cultivar

• Grass growth rate at a particular time of year

• Sport being played

• Mowing equipment

• Available labor/budget

The one-third guideline (do not remove more than one-third of the leaf blade at one mowing event) applies to most situations to balance root and shoot system development. This still allows for variation in the HOC, depending upon the species and season, providing the sports field manager opportunities to optimize turfgrass health and playing quality.

Frequent mowing at the lower range of acceptable HOCs for a species during periods of optimal turfgrass growth increases the rates of lateral growth from rhizomes and stolons and encourages tillering of bunch-type grasses without being a drain on nutrient acquisition and root production. Frequent mowing at the lowest HOC ranges for a species during environmental stress periods gradually weakens plant health, as shoot development is favored, compromising root growth and carbohydrate storage. Mowing too infrequently typically leads to a scalping event, which leaves excess clippings on the surface (creating shade, disease, and playability problems) and further depletes carbohydrate reserves of the plants, as recovery efforts are focused on regenerating shoots. Eventually, the playing surface may be deemed unfit for use.

Republished from SFMA’s Knowledge Center: Cultural Practices