Which is the best edging mild steel or Cor-Ten garden edging?

18 October 2022

Customers often ask which type of landscape edging they should choose for their garden or driveway project, the Classic galvanised powder coated mild steel, or the Cor-Ten garden edging. Both edging materials have been developed for their strength, durability, flexibility, and usability, both are excellent, so which should you go for?

Here is some more information to help you decide which EverEdge garden edging products are best for your project.

EverEdge Cor-Ten garden edging

What is Cor-Ten steel?

The word Cor-Ten is an amalgamation of ‘corrosion resistance’ and ‘tensile strength’. Tensile strength is the maximum stress a material can support without it fracturing when being stretched or pulled. Corten steel has a tensile strength of around 480 MPa: it’s an exceptionally strong high-quality steel.

Cor-Ten steel is also commonly called weathered steel. It contains an alloy that encourages the production of surface rust – and this is what makes Cor-Ten so special. The rust layer protects the steel underneath it from the elements and prevents degradation, but it also gives Cor-Ten its famed rust-coloured aesthetic. On installation the Corten steel edging is a dull silver colour with the rust developing over time with exposure to the elements which means the colour is unique.

Everedge Classic landscape edging

What is mild steel?

Mild steel is the raw material that comes from the mill. Mild steel, in comparison with Cor-Ten, has a comparatively low tensile strength of around 400MPa. If left untreated mild steel will rust. However, the Classic range of edging is galvanised – and this is important to note. Galvanisation increases the mild steel’s surface strength through carburisation by an additional 13%, so the product becomes incredibly strong and durable while protecting the steel from oxidisation (rust).

The Everedge Classic collection is also powder coated. Powder coating is where a heavy-duty polyester powder is bonded to the steel. Powder coating provides a protective barrier that helps prevent corrosion and corrosion and gives the opportunity to change the colour of the product.

What features do the Classic and Cor-Ten steel edging share?

1. Adds stunning texture, contrast and depth

2. Supports innovative and functional design

3. Looks fabulous in traditional and rustic garden settings

4. Minimal degradation over time

5. Easy installation with zero maintenance

What are the differences between Classic and Cor-Ten steel edging?

Longevity

While both products are highly durable, Cor-Ten has more longevity. However, the process for degradation of the mild steel is extremely slow. Even in acidic soil conditions and extreme weathers, mild steel degradation occurs at a rate of approximately 10 microns per year (0.01mm). To put this in perspective, it would take 50 years to degrade 1mm.

Aesthetic outcome

While aesthetic outcome of Corten garden edging weathers into a distinctive warm and varied brown patina. The natural process means climate conditions and the soil acidity influence the finish – the outcome is unique. The Classic collection is powder coated and available in brown or black, so you have more control over the outcome.

Cost

Cor-Ten steel products cost more than the Classic range. The higher cost is because it requires laser cutting to create the different sized edges.

If you have any further questions about which garden edging is best for your project, contact Everedge online or call 021 925 389. It’s a big decision, and we are always happy to help with garden edging and installation questions.

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Man installing edging along a lawn path in a garden.

The gardener’s guide to avoid garden edging mistakes

by Simon Mullinger • 25 August 2025

A well-designed garden isn’t just about the plants you choose; it’s the finishing touches that make all the difference. Garden edging frames your beds, pathways, and lawns, creating a clean, structured look while keeping soil, mulch, and grass exactly where they should be. But despite its time-saving capabilities, small mistakes during planning or installation can leave you with an untidy or high-maintenance garden – exactly what you didn’t sign up for. As a supplier of the best high-quality steel landscape edging products in New Zealand , EverEdge has heard it all – from shallow installs that allow grass to creep back in, to cracked or warped materials that ruin a carefully designed border. To help you get it right the first time, here are the top three garden edging mistakes and how you can avoid them. 1. Choosing the wrong edging material One of the most common mistakes is selecting edging that doesn’t stand the test of time. Plastic and timber edging might look appealing initially, but they deteriorate quickly over time, accelerated by harsh weather. Plastic warps under the sun, while timber is prone to rotting and shifting. Both often require replacement within just a few seasons. Even if you opt for the more expensive concrete garden edging it is vulnerable to ground movement and freeze-thaw cycles. By contrast, metal landscape edging, particularly steel garden edging, offers durability, flexibility, and a clean aesthetic. It can be shaped into sweeping curves or sharp angles without cracking, and it resists corrosion for decades. EverEdge products are designed for professional results and are trusted by landscapers across New Zealand for everything from garden bed edging and metal tree ring edging to driveway edging. Choosing a long-lasting material from the outset saves you time, money, and endless frustration down the line. 2. Installing at the wrong depth Even the best edging material won’t perform if it’s not installed correctly . A frequent error is laying edging too shallow. This allows mulch and soil to spill over and gives grass and weeds the perfect opportunity to creep back into your beds. Too deep, on the other hand, and the edging becomes buried, disappearing from sight and failing to give that crisp separation between lawn and border.