The string trimmer (weed eater or weed whacker) is primarily designed for detailed yard work like edging and trimming areas a conventional lawn mower cannot reach. While not intended for broad-area cutting, it can technically cut a whole lawn, though with practical caveats. This handheld tool uses a rapidly spinning nylon line and centrifugal force to create a stiff cutting mechanism that severs grass blades. Understanding its capabilities and limitations is key to deciding if it is the right tool for your lawn care needs.
Situational Use for Cutting Grass
Using a string trimmer as the sole grass-cutting tool is limited to very small lawns or specific terrain challenges. Properties 500 square feet or less can often be maintained entirely with a trimmer. This makes it a viable, economical option for urban yards where purchasing and storing a full-sized mower is impractical.
The trimmer also excels on terrain inaccessible or unsafe for standard mowers, such as steep slopes, ditches, or highly uneven ground. Its portability and maneuverability allow for necessary maintenance that prevents overgrowth. It is also effective for emergency grass cutting, or for tall, heavily overgrown grass that a mower might struggle to process.
Achieving a Consistent Cut
Technique and Movement
To maintain an even appearance, the user must adopt a specific technique. The most important factor is holding the trimmer head parallel to the ground, rather than angled downward. This horizontal position mimics a mower blade’s action, helping to prevent “scalping” the turf.
The movement pattern should involve wide, deliberate, sweeping motions from side to side, treating the area like a scythe. This allows the line to slice the grass blades cleanly and consistently. Users should walk slowly and steadily, slightly overlapping each cut swath to ensure full coverage and uniform height. Some trimmers feature small wheels or guides near the head that can serve as a physical reference point to maintain a consistent cutting height.
Line Management
Line management is integral to achieving an effective cut. The nylon line must be at the correct length to utilize the tool’s full cutting diameter. A line that is too short reduces efficiency and cutting power. Conversely, an excessively long line can cause the motor to bog down, especially in thick grass.
Maintaining the correct length ensures centrifugal force is maximized for efficient severing of the grass blades. Professional results are also achieved by walking in the direction the head spins, which helps propel clippings away and maintain better control.
Significant Limitations Compared to Mowing
Efficiency and Time Investment
Using a string trimmer for an entire lawn is significantly less efficient than a traditional lawn mower due to the dramatically narrower cutting width. A standard push mower typically covers a width of 20 to 22 inches, while a trimmer’s cutting path is usually 13 to 17 inches. This requires substantially more passes to cover the same area, potentially turning a 30-minute mowing job into a multi-hour trimming task.
Physical Strain
The physical demands on the operator are considerably higher, leading to increased fatigue and strain. Maintaining the required horizontal angle and consistent sweeping motion over a large area can exhaust the small muscles in the back and arms. Unlike a push or riding mower, which transfers the machine’s weight to the ground, the user must constantly support the full weight of the trimmer for the entire cutting duration.
Quality and Equipment Wear
Cut quality is a major drawback, as the spinning nylon line tears the grass blade with a flail-like action, creating a ragged wound on the plant tip. A sharp mower blade provides a cleaner, shearing cut that allows the grass to heal faster and reduces the chance of brown tips. Consistent height is difficult to maintain over large expanses, often resulting in an uneven appearance. Sustained use on a large lawn also puts increased wear on the trimmer’s motor, and battery-powered models necessitate frequent stops for recharging.