Bermuda grass is a warm-season turf known for its aggressive growth and ability to withstand high temperatures and drought. Unlike cool-season grasses, Bermuda grass thrives when maintained at a very short height, which is often counterintuitive to how many homeowners manage their lawns. This low-cut approach is a fundamental requirement of the plant’s biology that promotes a dense, carpet-like turf. Maintaining a short canopy forces the plant to focus its energy on lateral spread rather than vertical blade growth, resulting in the desired thick and resilient lawn.
The Physiology of Low Growth
The success of Bermuda grass under short cutting is due to its specialized growth structures, which allow it to spread horizontally. This grass is both stoloniferous and rhizomatous, producing two types of creeping stems that anchor and propagate the plant. Stolons are above-ground runners that extend along the soil surface, rooting at the nodes to form new plants.
Rhizomes are similar horizontal stems, but they grow underground, providing the plant with a protected energy reserve. These stems store carbohydrates, enabling the grass to recover quickly from stress, including frequent, low mowing and winter dormancy. When the leaf blades are constantly cut short, the plant responds by channeling its resources into stimulating more of these lateral runners.
This constant stimulation of lateral growth creates a dense turf that effectively chokes out weeds. A high cut, conversely, encourages vertical growth, causing the grass to become “stemmy” and thin out. This thinning leads to a weakened root system and greater susceptibility to weeds and environmental stress.
Defining the Ideal Mowing Height
The specific height at which Bermuda grass should be maintained depends on the variety and equipment, but the general range is significantly lower than for most other turf species. For common Bermuda grass varieties, a height between 1 to 2 inches is recommended for most home lawns. Hybrid Bermuda varieties, such as those used on athletic fields and golf courses, can be maintained even lower, typically between 0.5 inches to 1.5 inches.
Achieving the lowest heights, especially below one inch, usually necessitates the use of a reel mower, which cuts the grass cleanly with a scissor-like action. While rotary mowers can handle heights down to one inch, they generally perform better and cause less stress to the turf when set closer to the 1.5 to 2-inch range. Cutting too low for the grass variety or the unevenness of the lawn can lead to “scalping,” where the mower blade cuts into the stem tissue below the green canopy.
Scalping exposes the brown, woody stems, stressing the turf and temporarily hindering photosynthesis. While Bermuda grass is resilient and can recover from occasional scalping, consistently setting the height too low for the equipment or the lawn’s condition will cause damage. Conversely, allowing the grass to grow above three inches can lead to an accumulation of thatch—a layer of dead and living organic matter that prevents water and nutrients from reaching the soil.
Mowing Frequency and Technique for Short Bermuda Grass
Maintaining a short Bermuda grass lawn requires a heightened mowing frequency to prevent plant stress and maintain a consistent appearance. The guiding principle is the “one-third rule”: no more than one-third of the grass blade’s total height should be removed in a single mowing. Removing excessive leaf tissue severely shocks the plant, temporarily slowing root growth and making it vulnerable to heat and drought.
Due to the rapid growth rate of Bermuda grass, especially during the peak summer months, adhering to the one-third rule often requires mowing two to three times per week. For instance, if the desired height is 1.5 inches, the grass should be cut before it reaches 2.25 inches. If the grass is allowed to grow too tall, the height must be lowered gradually over several mowing sessions to avoid a severe scalping event.
The use of sharp mower blades is also a practical consideration for maintaining a short cut. Dull blades tear the grass, leaving frayed tips that give the lawn a whitish or brown cast and increase the plant’s susceptibility to disease.
Seasonal adjustments are necessary, particularly in the spring. As the grass begins to emerge from dormancy, a single, very low cut, often referred to as “scalping,” is performed. This removes the dead, brown top growth from the previous season, allowing the new green growth to emerge uniformly. This aggressive spring cut should be performed just as the soil temperature consistently hits around 55 degrees Fahrenheit, after which the grass should be maintained at its regular short height throughout the active growing season.