The Complete Guide to Timber Garden Edging for Australian Gardens

The secret to a neat, professional-looking garden bed? High-quality edging. It doesn’t just keep your mulch or soil where it belongs; it protects your lawn and defines your entire outdoor space.

As Melbourne’s landscaping experts, we know the soil and the materials that last in our climate. This guide breaks down exactly what you need to consider for timber garden edging, focusing on the quality products you can get right here at Soilworx.

Step 1: Choosing Your Timber (Durability is King)

When that timber is sitting against wet soil, durability isn’t just a suggestion, it’s a necessity. You need wood that’s treated or naturally tough enough to resist rot, moisture, and pests.

Soilworx Option	Key Benefit	Best For…	Expert Tip from Soilworx
Treated Pine (H4)	Best Value & Common Standard. The H4 treatment means this timber is specifically rated for in-ground contact, giving it the rot and termite resistance required for edging.	Straight runs, large-scale projects, or creating a neat, low-cost border. We stock it in economical 4.8m lengths (e.g., 4.8m x 25mm x 75mm).	The 25mm thickness is flexible enough for gentle curves, but use stakes every 1.5m to prevent bowing over time.
Hardwood Sleepers	Maximum Strength & Longevity. Hardwood options (like Ironbark) offer superior natural density, resistance to warping, and a premium, rustic look.	Heavy-duty boundary definition, very low retaining walls, or creating a defined, chunky aesthetic.	Use our Star Post Sleeper Brackets for an easy, heavy-duty install!
Plinth Boards	Taller, cleaner barrier. Often 150mm deep instead of 75mm, these are perfect for when you need a little more height to contain thicker layers of soil, mulch, or gravel.	Raised garden beds or defining the edge of a compacted pathway.	Combine these with our quality road base or gravels for a flawless finish.

Edible Garden Warning: If you are edging a vegetable or herb patch, many experts recommend using untreated hardwood or placing a plastic liner between the soil and Treated Pine (H4). Just something to keep in mind!

Step 2: Getting the Calculations Right (No Guesswork)

Don’t guess and run out of material or worse, over-order! Here is our simple formula for getting your order exactly right before you call us for fast Melbourne delivery.

Measure Your Perimeter

• Walk the boundary of your garden bed with a tape measure or a measuring wheel.
• Total Length (Metres) = Your Order Quantity.
• Soilworx Tip: Always add 10% extra to your total length for cutting, overlapping at corners, and the occasional mistake.

Calculate Your Stakes

Timber needs support! Whether you use Treated Pine Stakes or Steel Star Posts, you need enough to secure the run.

• Rule: Install a stake every 1 to 1.5 metres along the entire length.
• Example: If your border is 40 metres long, you’ll need 27 to 40 support stakes.

Need Help? Use our online volume calculator or just give the Soilworx team a call! We’re here to help you get the exact right quantity.

Step 3: Soilworx Installation Secrets for a Stable Edge

The difference between amateur edging and a border that lasts is in the preparation. Follow this three-step process to ensure a stable, long-lasting edge.

Dig and Seat the Base: 

Your edging shouldn’t sit entirely above ground. Dig a shallow, level trench so the bottom 2–3 cm of the timber is buried. This ‘seats’ the timber, locking it in place and providing a clean finish that’s easy to mow against.

Stake and Secure: 

Drive your stakes into the ground behind the timber. Use heavy-duty, weather-resistant screws or nails to attach the timber firmly to the stakes. Ensure your edging is straight before fixing it permanently.

Backfill and Compact: 

Once secured, backfill the trench on both sides with compacted soil, stone dust, or gravel. The pressure of the backfill prevents the edging from bowing outwards when the garden bed is full of our premium Veggie Mix Soil or mulch.

Pro-Tip for Rot Resistance

The place timber fails first is at the cut ends. When you cut a 4.8m Treated Pine Garden Edging piece to size, always treat the fresh cut end with a timber preservative or wood sealant. This seals the pressure-treated zone and dramatically increases the lifespan of your edge!

Ready to get your garden beds looking their best?

At Soilworx, we have the Treated Pine Edging, the Hardwood Sleepers, the Stakes, and the Bulk Soil you need to get the job done right. Order online today for our guaranteed, fast delivery across Melbourne and surrounding areas!