How to Use a Lawn Edger for Clean Borders
A defined edge between the lawn and driveways, sidewalks, and garden beds transforms the visual quality of even a mediocre lawn. The sharp line between turf and hard surface signals intentionality and care that broadens the overall impression of the landscape. Edging correctly requires the right tool for the surface, a consistent technique, and a maintenance frequency that keeps the edge defined rather than allowing grass to creep progressively into beds and paths.
Two Edging Methods
Rotary Edger (Stick Edger)
A rotary edger uses a spinning, blade-like disc that cuts vertically through the turf edge at the junction between grass and a hard surface. The blade rotates on a horizontal axis and cuts downward into the soil, creating a clean vertical wall between the grass edge and the surface being edged.
Rotary edgers are available in electric corded, battery-powered, and gas-powered versions. They are the most precise edging tool for straight edges along driveways and sidewalks, producing a crisp, deep-cut edge that requires less frequent maintenance than string trimmer edging.
Best for: Straight edges along driveways, sidewalks, and footpaths. Not suitable for curved bed edges.
String Trimmer (Weed Eater) Edging
A string trimmer turned sideways so the cutting line runs vertically rather than horizontally can produce a clean edge along straight and curved surfaces. This technique, called edging with a trimmer, is more versatile than a rotary edger because it can follow curved bed borders that a stick edger cannot navigate.
The result is not as precise as a rotary edger on straight surfaces but is acceptable for maintenance edging between full edger treatments.
Best for: Curved bed edges, areas a stick edger cannot reach, maintenance edging between full rotary edger treatments.
How to Use a Rotary Edger
Step 1: Position the guide wheel on the hard surface. The edger has a guide wheel that rides along the edge of the driveway or sidewalk. Position this wheel on the hard surface while the blade hangs over the grass edge, aligned with the existing turf-surface boundary.
Step 2: Start the edger and walk at a steady pace. Begin moving before engaging the blade in the soil if using a self-propelled or guided edger. Walk steadily along the edge, allowing the spinning blade to cut cleanly without being pushed too fast. Moving too quickly produces a ragged edge; moving too slowly allows the blade to dig excessively deep.
Step 3: Maintain a consistent angle. Keep the edger guide wheel flat on the hard surface throughout the run. Tilting the guide wheel produces an angled cut rather than a clean vertical edge.
Step 4: Clear the cuttings. After edging, a line of soil, thatch, and grass trimmings will be deposited along the edge. Blow or sweep these from the hard surface and either leave them on the lawn (where they break down quickly) or collect and compost them.
How to Edge With a String Trimmer
Step 1: Hold the trimmer correctly for edging. Rotate the trimmer 90 degrees from its normal position so the cutting head is vertical rather than horizontal. The cutting line should now spin in a vertical plane, cutting through grass like a saw rather than a mowing disc.
Step 2: Position the cutting head at the edge. The cutting line should be positioned at the edge of the turf, cutting no wider into the lawn than the clean edge requires. Most trimmer edging removes 0.5 to 1 inch of grass from the edge in maintenance passes.
Step 3: Walk along the edge at a steady pace. Walk forward along the edge while holding the trimmer steady, cutting through the grass overhang. The natural tendency is to tilt the trimmer, which results in a beveled or angled cut. Focus on keeping the cutting head perfectly vertical throughout.
Step 4: Manage the cut material. A trimmer throws cuttings, so edge in a direction that sends the material onto the lawn rather than onto the hard surface or into garden beds when possible.
How Often to Edge
Full rotary edger treatment: At the beginning of the mowing season to re-establish the edge after winter growth, and then every 4 to 6 weeks through the season to maintain the defined border. Edges that are neglected for an entire season require a more aggressive pass to cut back significant grass overhang.
Maintenance trimmer edging: After each mowing to keep light new growth from extending over the edge established by the rotary edger. A 30-second pass with a string trimmer held vertically along the edge after mowing maintains the appearance without requiring a full edger treatment every week.
Curved Bed Edges
For curved edges between lawn and garden beds, a half-moon edging tool (a flat spade with a sharp, flat blade) is the traditional approach for cutting a clean vertical wall along the bed border. Push the edger blade straight down along the bed line and lift out the plug of turf. This creates a defined trench between the lawn and the bed that channels any water runoff into the bed rather than onto the path.
Maintain curved bed edges with a string trimmer trimmed to the established line, or re-cut with the half-moon edger at the start of each season when new grass has crept into the trench.
Related Guides
For buying guidance on electric, cordless, and gas rotary edgers, see best lawn edger for clean, sharp borders.