How to Install Metal Landscape Edging? | Straight Cuts & Curves

Installing metal landscape edging requires digging a trench half the edging’s width deep, setting the strip, and securing it with stakes every 18–30 inches for a clean, durable border.

A crisp edge keeps mulch off the lawn and grass out of the beds. Metal edging does that for years without rotting or cracking like plastic and wood alternatives. The job takes a Saturday with basic tools, and the technique is the same whether you are framing a straight flower bed or bending around a tree. Before you start, check out our roundup of the best black metal landscape border options if you are still deciding which material to buy.

What You Need For The Job

The right tools make the difference between a clean line and a frustrating afternoon. You do not need specialized equipment—most of these are standard yard tools.

• Shovel: A half-moon shovel or sharpshooter spade cuts a clean narrow trench
• Mallet: Rubber mallet or a hammer with a wood block—never hit metal stakes directly with a steel hammer
• Cutting tool: Handsaw or angle grinder with a metal blade for trimming strips
• Hand tools: Long-handled pliers, a flat-head screwdriver, tape measure
• Layout supplies: Spray paint or chalk line, string, wooden stakes
• Safety gear: Leather or cut-resistant gloves and safety glasses are mandatory when cutting or hammering

Step-By-Step Installation

Every section runs the same basic playbook: mark the line, dig the trench, set the steel, stake it down, then bend and backfill. Here is the exact order that works with any standard metal edging kit.

1. Mark And Prep The Line

Lay out your path with spray paint or chalk. Drive wooden stakes at each end and run a tight string between them—this shows you the exact line and helps visualize height before you dig. Remove any sod, weeds, or debris along the path and level the ground with a rake.

2. Dig The Trench To The Right Depth

The golden rule: dig the trench half the width of the edging strip deep. An 8-inch strip needs a 4-inch trench. For strips taller than 4 inches, some professionals dig a trench ½ inch shallower than the material height so the edging stands slightly proud of the soil. Pour a thin layer of sand—roughly ½ inch—into the bottom of the trench to prevent water pooling and give the strip a level bed.

3. Set And Connect The Strips

Place the metal strip into the trench with the stake pockets or sleeves facing the garden side (inside). Different brands connect slightly differently, but the principle is the same: the next piece overlaps or locks onto the previous one:

• Edge Right systems use a clamp that fits between notches on both ends—push it into place and secure it
• Colmet Classic Steel Edging has stake pockets on the inside; one piece slides under the next for a seamless overlap
• Locking bump systems let tabs slide into holes on the adjacent piece; drive a screwdriver through the connected hole to lock them

4. Drive Stakes To Secure The Edging

Use a rubber mallet—or place a wood block over the stake and hammer the block—to drive stakes through the pockets or sleeves. Spacing matters: 18–24 inches apart is standard, though some brands allow up to 30 inches on straight runs. Always place a stake where two strips join, and cover sharp strip corners with a stake to prevent tripping hazards.

5. Bend Curves And Corners

Metal edging bends cleanly if you work it gradually. For gentle curves, stake the two end sleeves first so the strip can pivot, then work the middle into shape. For tight radiuses in 3mm steel, bend in small increments (about 1 inch apart) using long-handled pliers. A faster method for larger curves: lay a plank perpendicular to the steel, stand on the plank, and pull the metal upward to bend it evenly. To create a sharp corner, overlap the strips at the corner point and secure the overlap with a stake. SiteOne’s metal edging guide shows a block-and-brace method for crisp angles: place a block across the teeth of the bend and apply firm pressure.

6. Backfill And Finish

Backfill soil against both sides of the strip and compact it firmly with your hands or the shovel handle. Rinse the edging with a hose to remove mud. File down or fold over any sharp cut edges—especially important if kids play in the yard. Top the bed with mulch or decorative stone for a finished look.

Common Mistakes That Ruin The Job

These errors show up on every first-timer’s install, but they are easy to avoid once you know what to watch for.

• Hammering stakes with a steel hammer: Dents the stake and can split the pocket. Use a rubber mallet or a wood block every time
• Burying Corten (rusted) edging: Keep it visible above ground
• Wrong trench depth: Too shallow and the edging wobbles; too deep and it disappears. Stick to the half-width rule
• Skipping stakes at corners: Sharp exposed edges create tripping hazards. Always cap corners with a stake

FAQs

What gauge metal edging should I buy?

A lower gauge number means thicker steel and better durability. For residential use, 14-gauge (about 2mm) is a solid choice. Commercial-grade jobs often use 11-gauge or thicker. Heavier steel cost more upfront but resist bending under heavy soil or mower hits.

Do I need to remove grass before installing edging?

Yes—cut and remove sod along your marked line before digging the trench. Grass left under the edging will grow through or push the strip out of alignment. A half-moon shovel makes removing a clean strip of sod quick work.

Can metal edging handle tree roots?

Standard metal edging bends around roots over time rather than stopping them. For areas with aggressive tree roots, consider using flexible steel strips (like 3mm edge steel) that can accommodate ground movement without buckling.