Corten Steel Edging: The Complete Buyer's Guide for Australian Gardens
What Is Corten Steel Edging?
Corten steel, also known as weathering steel — is an alloy designed to form a stable, protective rust layer (called a patina) when exposed to the elements. Unlike regular mild steel that continues to corrode, corten develops its distinctive orange-brown finish and then stops. The result is a material that looks better with age and requires virtually zero maintenance.
When used as garden edging, corten steel creates clean, defined borders between lawns, garden beds, pathways, and gravel areas. It holds its shape year after year without warping, rotting, or fading — making it the go-to choice for landscapers and homeowners who want a lasting result.
Why Choose Corten Over Other Edging Materials?
There's no shortage of garden edging options on the market, so it's worth understanding what sets corten apart from the alternatives.
Corten vs timber edging: Timber looks great on day one, but it's fighting a losing battle against moisture, termites, and UV exposure. Most timber edging needs replacing every 5–8 years. Corten, by contrast, is rated for decades of service in direct ground contact — and it actually improves in appearance as the patina develops.
Corten vs Colorbond edging: Colorbond is a solid performer, but the powder-coated finish will eventually chip, scratch, or fade — especially at ground level where tools, mowers, and soil movement take their toll. Once the coating breaks down, the base steel underneath starts to rust unevenly. Corten sidesteps this entirely because the rust is the finish.
Corten vs plastic or composite edging: Plastic edging is cheap upfront but tends to become brittle in Australian sun, cracking and shifting within a few seasons. It also can't hold a straight line under pressure the way steel does. Corten gives you rigid, permanent lines that won't move once installed.
What Can You Use Corten Edging For?
Corten garden edging is more versatile than most people realise. Here are the most common applications we see at Thompson Co Outdoors:
- Garden bed borders: The most popular use. Corten edging separates mulched beds from lawn, giving your garden structure and preventing soil migration.
- Pathway and driveway edges: Corten holds gravel, decomposed granite, and paving in place with a clean architectural line.
- Lawn separation: Define lawn areas from gravel or planting zones without the need for a physical barrier above ground level.
- Raised bed walls: Taller corten edging (150mm–300mm) can function as a low raised bed, ideal for herbs, succulents, or feature plantings.
- Curved garden designs: Corten is flexible enough to follow gentle curves when installed correctly, making it ideal for organic, flowing garden layouts.
Corten Edging Heights and Thicknesses
At Thompson Co Outdoors, we fabricate our corten edging in-house using our guillotine and roller, which means we can offer a range of standard sizes and accommodate custom requests.
Common heights range from 75mm (ideal for flush lawn borders) through to 300mm or more for raised bed applications. The most popular heights for residential landscaping tend to sit between 100mm and 200mm — tall enough to contain mulch and define the border, without dominating the visual space.
Thickness matters for longevity. We recommend 2mm as a minimum for residential garden edging, with 3mm being the sweet spot for most projects. If you're edging driveways or commercial areas where there's vehicle or machinery traffic nearby, stepping up to 3mm or heavier provides extra rigidity and lifespan.
How the Patina Develops
One of the most common questions we get is: “Will it arrive rusty?” The short answer is that corten edging typically ships in a raw, mill-finish state, a dark grey-brown steel. The iconic rust patina develops naturally once the steel is exposed to weather.
In most Australian conditions, you'll start to see colour change within the first few weeks. A full, even patina usually establishes itself within 6–12 months depending on rainfall, humidity, and how exposed the edging is. The process is entirely natural and maintenance-free, just install it and let the weather do the rest.
Installation Basics
Installing corten edging is a straightforward job that most confident DIYers can handle in a weekend. The general process involves:
- Mark your layout using string lines or a garden hose for curves.
- Dig a shallow trench — typically 50–80mm deep, depending on the edging height and how much you want sitting above ground.
- Place the edging into the trench, ensuring it sits level.
- Secure with stakes — corten steel stakes driven into the ground at regular intervals (every 600–800mm) hold everything firmly in place.
- Backfill both sides with soil or mulch to lock the edging in position.
For a seamless look without visible fixings, consider our conceal fixing corten edging, which uses a hidden stake system for a completely clean finish.
Standard Edging vs Conceal Fixing Edging
We offer two main types of corten edging at Thompson Co Outdoors. Standard corten edging is secured with visible stakes driven through or beside the steel — simple, effective, and the most affordable option.
Conceal fixing corten edging uses a specially designed bracket system that sits behind the steel, so no fixings are visible from the front. Landscapers love it for high-end residential projects, courtyard gardens, and commercial streetscapes where a seamless finish matters.
Both options use the same quality corten steel and develop the same patina — the difference is purely in the fixing method and the resulting visual finish.
How to Order from Thompson Co Outdoors
All of our corten edging is fabricated in-house at Thompson Co Outdoors using our own guillotine and roller. That means we control quality from start to finish and can turn orders around quickly.
Browse our corten edging collection to see available sizes, or get in touch if you need a custom length, height, or radius. We deliver Australia-wide, and our team is always happy to help you work out quantities and specifications for your project.
