Mowing height for lawn grasses in Georgia:
• Tall fescue: 2-3 inches
• Common bermudagrass: 1-2 inches
• Hybrid bermudagrass: 0.5-1.5 inches
• Zoysia : 0.5-1.5 inches
• Centipedegrass: 1-1.5 inches
Mowing is the most frequent and therefore generally the most expensive turf management practice used. It can also affect turf quality as much as any other cultural practice.
Proper mowing includes cutting at the recommended height and mowing often enough to remove no more than one-third of total leaf area. The cutting height for a given turf is determined by turf vigor, turf use and turf growth habit.
The most effective mowing height varies considerably among turf species.
Cutting heights actually used result from a compromise between the appearance desired and the factors limiting turf health and vigor.
Generally, as cutting height is lowered turfgrasses reduce food production and storage, increase shoot growth and density, decrease leaf width and root and rhizome growth.
Lowering the cutting height dramatically reduces rooting depth, root number and total root production.
However, when a turfgrass is mowed within its adapted height, the lower mowing heights generally result in improved turf quality as long as other turf growth needs are met.
Reduced turf quality and vigor are the first signs of excessively close mowing and are generally followed by weed encroachment.
Since lowering the mowing height generally reduces turf vigor, it also generally reduces turf stress tolerance. Therefore, raising the mowing height during drought stress, prior to winter dormancy for warm season turfgrasses, and in heavy shade is commonly recommended.
Mowing a hybrid Bermudagrass too high results in long stems with few leaves and little color. This high cutting height also results in excess thatch accumulation, which makes the turf more susceptible to scalping, disease and weed problems and stress.
Scalping is the removal of too much leaf area (greater than 40 percent) at any one mowing.
Scalping causes the plant to use stored foods, which weakens the grass and results in reduced root and rhizome growth.
Temporary thinning can occur from scalping.
Scalping can be avoided by mowing more frequently, therefore removing less than 40 percent of the leaf area.
The general rule recommended is to mow often enough to remove no more than one-third of the leaf area.
With the hybrid Bermuda grasses, summer scalping because growth rate exceeds mowing frequency is quite common.
This can be minimized by avoiding fertilization during these periods of rapid growth or by increasing mowing frequency.
Mowing has both visible and invisible effects on a turfgrass plant. Proper mowing involves cutting at the correct height, and cutting frequently enough to prevent scalping. This leads to a healthier, more vigorous plant and results in a high quality turf.
For additional information on lawn maintenance, contact the Dawson County Extension Office at (706) 265-2442.
Clark Beusse is the Dawson County extension agent.