The choice of lawn mower determines how a grass blade is severed, which significantly affects the turf’s overall health and appearance. While the common rotary mower uses a high-speed, horizontal blade, the reel mower employs a specialized mechanism that treats the grass plant differently. Understanding this distinction is key to achieving the dense, green lawn often associated with professional turf management.
The Mechanism of the Clean Cut
The operation of a reel mower is analogous to a pair of scissors, creating a precise shearing action to cut the grass blade. This mechanism involves a set of helical blades, known as the reel, which rotates and pushes the grass against a stationary bottom blade called the bedknife. The grass is cleanly snipped between these two surfaces, resulting in a surgical cut that minimizes damage to the cellular structure of the leaf.
In contrast, the standard rotary mower relies on a single or multiple blades spinning at high velocity to impact the grass. This rapid rotational speed delivers a powerful blow that chops the grass, but it often results in a less controlled, tearing action. The effect is similar to hitting the grass with a dull machete, where the high force is meant to compensate for a lack of precision.
The physics of the rotary cut leaves a ragged, bruised edge on the grass blade. This blunt-force trauma to the plant tissue requires the grass to expend more energy on healing the wound. A clean shear from a sharp reel mower, however, inflicts minimal physical stress on the plant, allowing it to recover more quickly.
Superior Grass Health and Appearance
The clean severance achieved by a reel mower directly translates into improved turf health at a microscopic level. A ragged cut from a rotary blade exposes a larger, frayed surface area on the tip of the grass, which leads to excessive water loss through desiccation. This increased surface area also provides a wider, more accessible entry point for fungal spores and other turfgrass pathogens.
The aesthetic result of this tearing is visible as “browning tips” or a whitish haze across the lawn a day or two after mowing. This discoloration is actually dead, dried-out tissue where the plant has been traumatized by the impact cut. The reel mower’s clean cut prevents this widespread cellular damage, preserving the uniformity of the green color and promoting rapid wound closure.
Reel mowers are also engineered to maintain a much lower height of cut than most rotary models, often down to half an inch or less. This frequent, low cutting encourages the grass plant to shift its growth from vertical to lateral, a process called tillering. The result is a denser, more carpet-like turf that naturally competes better against weeds. The rollers on reel mowers also bend the grass blades in a uniform direction, which reflects light differently to create the highly sought-after striping effect seen on golf courses.
Practical Requirements for Use
Achieving the health and appearance benefits of a reel mower requires specific turf conditions and increased user commitment. Reel mowers are best suited for fine-bladed, low-growing grass varieties, such as Bermuda, Zoysia, Bentgrass, and certain Fescues. They are not designed to handle the tall growth or thick stems of common lawn weeds, which are often simply pushed over instead of cleanly cut.
The maintenance demands of a reel system are more complex than those of a rotary mower. The precision cutting relies on a hair-thin clearance between the reel and the bedknife, which must be regularly checked and adjusted. Professional sharpening requires specialized grinding equipment, often referred to as grinding or backlapping, which is a more involved and costly process than simply sharpening a standard rotary blade.
A reel mower cannot efficiently remove more than about one-third of the grass blade’s height at a time, especially at low cutting heights. This necessitates mowing the lawn two to three times per week during peak growing seasons to prevent the grass from getting too tall. While manual push models offer a cost-effective and low-noise option, high-quality, powered reel mowers that can handle larger yards represent a significantly higher initial investment compared to their rotary counterparts.