Steel vs Plastic Garden Edging: Which Is Right for You?

When it comes to garden edging in Australia, steel and plastic are the two most popular choices for home gardeners. Both materials have passionate advocates and genuine advantages, but they also have distinct differences that make each better suited to certain situations. In this honest comparison, we'll examine both options in detail to help you make an informed decision for your garden.

Understanding the Fundamental Differences

Before diving into specific comparisons, it's worth understanding what makes these materials fundamentally different. Steel edging is a rigid, durable material that creates clean, permanent lines in your garden. It's manufactured from either galvanised or Corten steel, both of which offer excellent longevity.

Plastic edging, on the other hand, is typically a flexible material that can be easily shaped to follow curves and contours. Modern plastic edging ranges from basic polyethylene strips to sophisticated recycled composite materials that mimic the appearance of more expensive options.

Durability and Longevity

When it comes to lifespan, steel edging is the clear winner. Quality galvanised steel edging can last 20 years or more with minimal maintenance, while Corten steel develops a protective patina that extends its life even further. We've seen steel edging installations from the 1990s still performing perfectly in Australian gardens.

Plastic edging varies considerably in durability depending on quality. Budget plastic edging might last only 3-5 years before becoming brittle and cracking, especially in areas with intense UV exposure. Premium UV-stabilised plastic can last 10-15 years, but still falls short of steel's longevity.

It's worth noting that Australian conditions are particularly harsh on plastic materials. Our intense UV radiation can accelerate degradation significantly, which is why we always recommend UV-stabilised products if you choose the plastic route.

Cost Comparison

The initial cost difference between steel and plastic is substantial. Basic plastic edging can cost as little as $2-5 per metre, making it accessible for gardeners on tight budgets. Steel edging typically ranges from $15-40 per metre depending on the type and supplier.

However, the true cost picture becomes more nuanced when you consider longevity. If you replace budget plastic edging three times over 15 years, you may actually spend more than you would on a single steel installation. Here's a simplified comparison:

Budget Plastic (5-year lifespan): $3/m × 3 replacements = $9/m over 15 years, plus installation time

Steel (20+ year lifespan): $25/m one-time cost, minimal maintenance

When you factor in the time and effort of multiple installations, steel often represents better value for gardeners who plan to stay in their homes long-term. However, if you're renting, planning to sell soon, or simply need a quick temporary solution, plastic's lower upfront cost makes perfect sense.

Aesthetic Considerations

Appearance is often the deciding factor for many gardeners, and this is where personal preference plays a significant role.

Steel edging creates clean, crisp lines that suit modern and contemporary garden designs. Galvanised steel has a silvery-grey industrial appearance that works beautifully with minimalist landscaping, architectural plants, and modern home designs. Corten steel offers a warm, rusty aesthetic that complements native Australian plants and creates a more organic, established feel.

Plastic edging is more subtle by design—it's meant to disappear into the landscape rather than be a feature itself. This can be an advantage if you want the focus on your plants rather than your borders. However, it also means plastic adds less visual interest to your garden.

Installation Difficulty

Plastic edging is generally easier to install, making it popular with DIY gardeners. Most plastic edging products are lightweight, easy to cut with basic tools, and flexible enough to follow curves without special techniques. A typical plastic edging installation can be completed by a single person in a weekend.

Steel edging requires more effort but is still achievable for competent DIYers. The main challenges are the material's weight, the need for proper stakes or anchoring, and creating clean cuts (which typically requires an angle grinder). Curves can be created with steel, but require either specialised flexible steel products or careful bending techniques.

For straight borders and simple shapes, both materials are manageable DIY projects. For complex designs with tight curves, plastic has a clear advantage in ease of installation.

Performance in Australian Conditions

Australia's diverse climate zones create different challenges for garden edging materials. Here's how steel and plastic perform across various conditions:

Hot, Dry Climates (WA, SA, inland areas)

Steel performs excellently in hot, dry conditions with minimal expansion or degradation. Plastic can become brittle and crack under intense heat and UV exposure, though premium UV-stabilised products fare much better.

Tropical and Humid Areas (QLD, NT, northern NSW)

Both materials handle humidity well, but galvanised steel is the better choice in areas with constant moisture. Standard (non-galvanised) steel would rust quickly, while plastic is unaffected by humidity. However, the intense tropical sun can still degrade plastic over time.

Coastal Locations

Salt spray accelerates corrosion in steel edging, making galvanised steel essential for coastal gardens. Plastic is completely unaffected by salt, making it an excellent choice for beachside properties where budget is a concern.

Cold and Frost-Prone Areas (Tasmania, alpine regions, southern highlands)

Steel handles freezing conditions without issue. Some plastic products can become brittle in extreme cold, though this is less of a concern in most Australian locations.

Environmental Considerations

For environmentally conscious gardeners, both materials have pros and cons.

Steel is highly recyclable and can be repurposed at the end of its life. Australian steel production has become increasingly sustainable, and the material's longevity means less frequent replacement and less waste overall.

Plastic edging raises more complex environmental questions. On one hand, many products now use recycled plastics, diverting waste from landfill. On the other hand, plastic that does end up in landfill can persist for centuries, and lower-quality plastics may degrade into microplastics over time.

If sustainability is a priority, look for recycled plastic products or invest in long-lasting steel to minimise your environmental footprint.

Maintenance Requirements

Both steel and plastic edging are relatively low-maintenance, but there are some differences to consider.

Steel edging requires occasional inspection for loose stakes and may need adjustment if soil movement occurs. Galvanised steel should be checked periodically for any damage to the zinc coating, which could lead to rust. Corten steel requires no maintenance—the rust is the point!

Plastic edging may need repositioning more frequently as it can shift over time, particularly in areas with active soil movement. Cracked or damaged sections need prompt replacement to maintain effectiveness. Some plastic products may also fade or discolour with sun exposure.

Our Recommendation

After testing dozens of products over the years, here's our honest assessment:

Choose steel if:

• You want a long-term solution that will last decades
• You prefer a modern, architectural aesthetic
• You're willing to invest more upfront for better value over time
• You're creating straight borders or gentle curves
• You want to add visual interest with Corten steel's rusty patina

Choose plastic if:

• Budget is your primary concern
• You need to create complex curves or organic shapes
• You're renting or may move soon
• You want a quick, easy DIY installation
• You prefer your edging to be invisible

There's no universally "best" choice—both materials have their place in Australian gardens. The right choice depends on your specific circumstances, priorities, and garden design.

Ready to explore your options? Browse our curated selection of steel and plastic edging products to find the perfect solution for your garden.