Steel garden edging creates clean, professional-looking borders that can transform your outdoor space. While hiring a professional landscaper is always an option, installing steel edging is a manageable DIY project for anyone with basic tool skills and a free weekend. In this comprehensive guide, we'll walk you through the entire process, from preparation to final touches.
Tools and Materials You'll Need
Before starting your installation, gather all necessary tools and materials. Having everything ready will make the process smoother and prevent frustrating trips to the hardware store mid-project.
- Measuring tape (at least 5m)
- String line and stakes
- Spirit level (1m length recommended)
- Rubber mallet or dead blow hammer
- Spade or half-moon edger
- Garden hose (for marking curves)
- Work gloves (steel edges are sharp!)
- Safety glasses
- Angle grinder with metal cutting disc (for cuts)
Materials needed:
- Steel edging strips (measure your border plus 10-15% extra)
- Steel stakes (typically one every 600mm-1m)
- Connector pieces (if your product requires them)
- Marking spray paint (optional, but helpful)
Step 1: Planning and Measuring
Proper planning is the foundation of a successful installation. Take time at this stage to avoid costly mistakes later.
Start by walking around your garden and deciding exactly where you want your edging to go. Consider sight lines from your windows and outdoor living areas—your edging should enhance these views, not detract from them.
For straight borders, use stakes and string line to mark your intended path. For curves, lay a garden hose along the ground and adjust until you achieve a pleasing shape. Stand back and view from multiple angles before committing.
Once satisfied with your layout, measure the total length using a measuring tape. Walk the entire perimeter, measuring each section and recording the numbers. Add these together, then add 10-15% to account for cuts, connections, and any adjustments you might need to make.
Measure twice, order once. Running short of materials mid-installation is frustrating and can result in mismatched products if you order from a different batch later.
Step 2: Preparing the Installation Area
With your materials on hand, it's time to prepare the installation area. This preparation work directly impacts the final quality of your installation.
Begin by removing any existing edging, debris, or obstacles from the installation path. If there's existing lawn where you want to install edging, use a half-moon edger or spade to cut a clean line. This also helps prevent grass from growing over your new edging.
Use a spade to dig a shallow trench along your marked line. The trench should be deep enough to accommodate the edging at the correct height—typically with the top of the edging sitting 10-20mm above the lawn level. This height allows the edging to contain mulch effectively while still permitting easy mowing right up to the edge.
The trench doesn't need to be wide—just enough to fit the edging and allow room for stakes. About 50-75mm wide is usually sufficient for most steel edging products.
Step 3: Setting the First Section
The first section establishes the reference point for your entire installation, so take extra care to get it right.
Position your first piece of edging in the trench, using stakes and string line to ensure it's perfectly aligned with your planned layout. Use a spirit level to check that the top edge is level—this is crucial for straight sections, though gentle natural undulations are acceptable and often look more natural.
Once the first section is properly positioned, install the first stake. Drive it through the stake holes in the edging using your rubber mallet, angling the stake slightly inward toward the garden bed side. This angle helps the stake resist pressure from soil and roots pushing against the edging.
Don't drive the stake fully home yet—leave it slightly raised until you've installed several sections and confirmed everything is aligned correctly.
Step 4: Installing Subsequent Sections
With your first section established, continue along your planned route. Most steel edging systems use interlocking or overlapping connections, but methods vary by manufacturer, so follow the specific instructions for your product.
General principles apply regardless of the connection system:
- Maintain consistent height along the entire installation
- Keep checking alignment against your string line
- Install stakes at regular intervals (typically every 600mm-1m)
- Ensure connections between sections are secure but not forced
For straight runs, maintaining a consistent line is relatively straightforward. Simply follow your string line and check levels regularly. If you notice any sections rising or falling out of alignment, adjust before installing more stakes.
Step 5: Creating Curves
Curves add visual interest to garden borders but require additional technique with steel edging. The approach depends on your edging type and the tightness of the curve.
For gentle curves, most steel edging can be flexed gradually over its length. Work slowly, bending the edging a little at a time while securing with stakes. Avoid trying to create tight bends in a single spot, as this can kink the steel.
For tighter curves, use shorter sections of edging and create the curve through a series of small angle changes at each connection point. This produces a smoother appearance than trying to bend a single long piece.
Some manufacturers offer flexible steel edging specifically designed for curves. These products typically have a narrower profile or pre-scored bending points that make curve creation much easier. If your design includes many curves, these specialty products are worth considering.
Step 6: Cutting Steel Edging
Unless you're extremely lucky, you'll need to cut at least a few pieces to fit. Steel edging can be cut with an angle grinder fitted with a metal cutting disc.
Before cutting, measure carefully and mark your cut line clearly. Remember the old carpenter's rule: measure twice, cut once. Always wear safety glasses and work gloves when cutting steel—the edges will be sharp and sparks will fly.
After cutting, the exposed edge may be sharp and prone to rust. Apply a rust-preventative coating (cold galvanising spray works well for galvanised steel) to protect the cut end and smooth any sharp edges with a metal file.
Step 7: Final Adjustments and Finishing
Once all sections are installed, walk the entire length and make final adjustments. Check that:
- The top edge is at a consistent height throughout
- All sections are properly aligned
- Connections are secure
- Stakes are properly positioned and don't protrude above the edging
Now drive all stakes fully home using your rubber mallet. The stake tops should be flush with or slightly below the top of the edging.
Backfill both sides of the edging with soil, compacting gently as you go. On the garden bed side, the soil level can be higher to accommodate mulch. On the lawn side, ensure the soil is at a level that allows easy mowing right up to the edge.
Common Installation Mistakes to Avoid
Learn from others' mistakes to ensure your installation is successful:
Mistake 1: Inadequate preparation. Rushing through planning and preparation leads to wonky lines and uneven heights. Take the time to mark your layout properly and dig a consistent trench.
Mistake 2: Installing edging too high or too low. Edging that sits too high becomes a tripping hazard and looks awkward. Edging that sits too low fails to contain mulch effectively. Aim for 10-20mm above lawn level.
Mistake 3: Not using enough stakes. Under-staked edging will shift and move over time, particularly in areas with active soil movement or tree roots. Don't skimp on stakes—one every 600mm is ideal for most installations.
Mistake 4: Forcing connections. If sections don't connect easily, don't force them. Check for debris or damage, and ensure the previous section is properly aligned. Forced connections often fail over time.
Mistake 5: Ignoring drainage. Edging shouldn't block natural water flow through your garden. If your edging runs across a natural drainage path, consider installing a small gap or weep hole to allow water to pass.
Maintenance After Installation
Steel edging requires minimal ongoing maintenance, but periodic checks will keep it looking great:
- Inspect annually for any signs of movement or loosening
- Re-stake any sections that have shifted
- Check galvanised edging for any damage to the zinc coating
- Trim back grass and roots that grow up to or over the edging
- Adjust soil levels on either side if erosion or settling occurs
With proper installation and basic maintenance, your steel edging will serve your garden beautifully for 20 years or more.
When to Call a Professional
While steel edging installation is DIY-friendly, some situations warrant professional help:
- Very large installations (50+ metres) may benefit from professional efficiency
- Complex designs with many tight curves or intersections
- Installations on slopes requiring retaining functions
- Areas with extensive tree roots or underground utilities
- If you lack the necessary tools or physical capability for the work
There's no shame in hiring help when needed—a professional installation ensures lasting results and saves potential frustration.
Ready to start your project? Explore our recommended steel edging products to find the perfect option for your garden.