Edging Techniques for a Perfect Lawn

Nothing transforms a garden's appearance quite like clean, defined edges. Professional landscapers know that even an average lawn looks manicured when its boundaries are sharp and precise. The difference between a garden that looks "okay" and one that looks "professionally maintained" often comes down to edging technique.

Your whipper snipper is capable of producing edges that rival dedicated edging machines—you just need to master the right techniques. This guide covers everything from basic vertical edging to advanced methods for garden beds and difficult curves.

Understanding the Two Types of Edging

Before diving into technique, it's important to understand the two distinct types of edging:

Vertical Edging

This is what most people picture when they think of edging: a clean vertical cut along a hard surface like a driveway, footpath, or patio. The goal is to create a sharp line where grass meets concrete or pavers, with no grass creeping over the edge.

Horizontal Edging (Scalping Prevention)

This refers to trimming grass horizontally around obstacles—trees, fence posts, garden ornaments—where your mower can't reach. The goal here is to match the height of the surrounding mowed lawn without scalping (cutting too short) or leaving uneven patches.

Different techniques apply to each type, and mastering both is essential for a professional-looking garden.

Mastering Vertical Edging

The Basic Technique

1. Position the trimmer: Rotate your whipper snipper 90 degrees so the cutting head is vertical, perpendicular to the ground. The spool should be parallel to the edge you're cutting.
2. Use the correct side: Keep the right side of the cutting head toward the hard surface (for right-handed, counter-clockwise spinning trimmers). This throws debris away from you and the edge.
3. Lower the head carefully: Bring the cutting line down to just touch the edge where grass meets hard surface.
4. Walk steadily: Move along the edge at a consistent pace, keeping the cutting head at the same height throughout. Slow and steady wins the race.
5. Focus on the line: Watch where the line meets the edge, not the cutting head itself. This helps maintain a straight, consistent cut.

Depth Control

The depth of your edge cut matters. Cutting too deep (more than 2cm below the hard surface) creates a trench that fills with debris and looks untidy. Cutting too shallow leaves grass tips visible. Aim for a cut that's approximately 1-2cm deep—enough to create a clean visual break without creating a gutter.

Dealing with Overgrown Edges

If grass has crept over paths or driveways (common with kikuyu and buffalo), you may need a multi-pass approach:

1. First pass: Remove the bulk of overhanging grass horizontally
2. Second pass: Establish the vertical edge
3. Third pass: Refine and clean up the edge

Trying to do too much in one pass on overgrown edges often results in the trimmer line breaking or uneven cutting.

Horizontal Trimming Around Obstacles

Matching Mower Height

When trimming around trees, posts, and obstacles, your goal is to match the height of the surrounding mowed lawn. This requires holding the trimmer at a consistent height while moving around the obstacle.

Tree Ring Technique

1. Approach the tree from one side, holding the trimmer at mowing height
2. Work around the tree in a circular motion, keeping the cutting head level
3. Overlap your passes slightly to ensure even cutting
4. Keep the trimmer line at least 5cm from the tree trunk to avoid bark damage

Advanced Techniques

Garden Bed Edging

Creating clean lines along garden beds requires a hybrid approach. The edge where lawn meets mulch or soil should be defined but natural-looking:

• Use a slight angle rather than fully vertical to create a gentle transition
• Be careful not to throw mulch onto the lawn with the spinning line
• Consider the sweep direction to control debris

Curved Edges

Curves require extra attention to maintain a smooth, flowing line:

• Slow down on curves—faster movement creates choppy edges
• Keep your body positioned consistently to the edge as you follow the curve
• Use shorter, more controlled movements
• Step back periodically to check your work and ensure the curve flows naturally

Fence Line Finishing

Fence lines present unique challenges with posts, rails, and tight spaces:

• Work in one direction along the fence for consistency
• Tip the trimmer head slightly to get under the lowest rail
• Be careful around fence posts—hitting them damages the line and can chip paint or timber
• Consider a curved shaft trimmer for easier access to tight fence line areas

Common Edging Mistakes to Avoid

• Moving too fast: Rushing creates uneven, choppy edges. Slow, steady movement produces the cleanest results.
• Inconsistent height: Varying the cutting height creates a wavy edge line. Pick a height and maintain it.
• Scalping: Cutting too low around obstacles stresses grass and looks bad. Match mowing height.
• Over-edging: Creating trenches by cutting too deep along hard surfaces. Aim for 1-2cm depth maximum.
• Neglecting line length: Running with too little line exposed. Tap to advance line regularly for optimal cutting.

Maintenance Edging vs. Restorative Edging

Once you've established clean edges, maintaining them is much easier than the initial creation. Weekly touch-ups with minimal passes keep edges sharp with minimal effort. The key is not letting them become overgrown again—regular light edging is far less work than occasional heavy restoration.

Make edging part of your regular mowing routine, even if just a quick pass along the most visible edges. Your garden will look consistently polished without requiring marathon sessions.