How deep should garden edging be installed in Australia?

Garden edging in Australia should be installed with 50 to 75 millimetres buried below finished ground level. This depth prevents vigorous runners from turf varieties like Kikuyu and Couch from invading garden beds. Leave 15 to 25 millimetres protruding above the soil surface to retain mulch without damaging lawn mower blades.

What is the best garden edging for Australian soil and weather conditions?

Corten weathering steel and galvanised steel are the most durable options for Australian conditions, resisting UV degradation, termites, and brushcutter damage. Recycled composite edging works best for curved layouts in coastal areas, while H4-treated pine sleepers or extruded concrete kerbing suit straight runs requiring structural soil retention.

Do you need a council permit to install garden edging in Australia?

Standard garden edging under 1 metre in height does not require a council permit on private Australian residential properties. However, if the edging acts as a soil-retaining structure over 1 metre, or alters natural stormwater overland flow paths onto neighbouring allotments, building approvals and engineering certifications apply under local planning schemes.

What are common mistakes when installing landscape edging?

Common mistakes include setting the edging too high above the turf line, failing to anchor stakes at manufacturer intervals, and digging without submitting a Before You Dig Australia enquiry. Overly high edging creates trip hazards and scalp risks for lawnmowers, while inadequate anchoring allows soil pressure to bow the edging line over time.

How do you stop grass runners from spreading under garden borders?

To stop aggressive rhizomatous turf varieties like Couch, Kikuyu, and Buffalo from penetrating garden beds, install edging with a continuous solid barrier extending at least 75 millimetres below ground. Ensure all segment joints interlock tightly, and install a compacted roadbase or crushed aggregate strip directly beneath paver borders.

How to install garden edging for a neat and low-maintenance border

Learn how to install garden edging in Australia. Trench 50–75 mm deep, stake securely, and finish flush to soil for neat, low-maintenance landscape borders.

Quick answer

To install garden edging, excavate a trench 50 to 75 millimetres deep along your border line to block running turf roots. Secure edging strips with ground stakes placed every 1 to 1.5 metres, then backfill firmly with compacted soil to leave 20 millimetres exposed for mower clearance.

Skill level: Beginner to Intermediate
Time: 4–8 hours for 10–20 m depending on edging type, soil conditions, and whether curves are included.
Trade: Earthmoving & Landscaping
Updated: 3 November 2026

Tools you will need

Cyclone Square Mouth Trenching Shovel - 150 mm
Spear & Jackson Trade Post Hole Mattock - 2.2 kg
Stabila 70-2 Double Plumb Spirit Level - 1200 mm
Estwing Sure Strike Rubber Mallet - 24 oz
Lufkin Shockforce Dual Sided Tape Measure - 8 m
Sakai or Kubota U17-3 Mini Excavator - 1.7 t
Kelso Poly Pro Heavy Duty Wheelbarrow - 100 L

What is involved in installing garden edging for a neat and low-maintenance border?

🏗️ Garden edging installation for a clean, low-maintenance finish

Installing garden edging is a straightforward landscaping upgrade that creates a crisp separation between lawn, paths, and garden beds while reducing grass spread and mulch spill. For Australian homeowners, it’s an ideal weekend project that improves street appeal, makes mowing easier, and cuts ongoing garden maintenance when set out and installed properly.

What skill level is required for garden edging installation?

Beginner to Intermediate — Estimated time: 4–8 hours for 10–20 m depending on edging type, soil conditions, and whether curves are included.

What tools are required for installing garden edging in Australia?

🔧 Equipment Required

String line, timber pegs and marking paint for setting out straight or curved runs

Tape measure at least 5 m

Spade or trenching shovel for cutting the edge line

Mattock for hard ground and roots

Rubber mallet for tapping edging into position

Spirit level or laser level for maintaining a consistent finished height

Hand tamper or plate compactor for compacting backfill on longer runs

Wheelbarrow for spoil and material movement

Angle grinder with suitable blade or tin snips/hacksaw depending on edging material

Drill/driver and bits if fixing timber or modular edging systems

Mini excavator 1.7t–2.5t only if doing major bed reshaping or long runs over 50 m

PPE: safety boots, gloves, safety glasses, hearing protection, long sleeves, sun protection and dust mask where cutting is required

💡 For a once-off DIY project under 20 m, hire is usually more economical than buying a compactor or laser. For repeated landscape jobs or property upgrades, buying may stack up, while machines and tool packages over $20k may be worth discussing with Local Knowledge Finance.

What materials are commonly used for garden edging in Australia?

Garden edging of choice:

Steel edging typically 75–150 mm high

Plastic edging with stakes

Timber sleeper edging such as H4 treated pine

Concrete or masonry edging units for formal borders

Fixing pins, stakes or joiners to suit system

Road base or crusher dust if bedding is required

Backfill soil

Mulch for garden bed top-up

Galvanised screws/bolts if using timber systems

Weed mat only if part of a broader bed build-up, not as a substitute for proper edging

Optional concrete for haunched support on heavy masonry edging

Turf underlay or topsoil for finishing lawn edge if needed

Safety Requirements

⚠️ Safety

📞 Dial Before You Dig (1100) before any excavation, even for shallow edging trenches, to check for buried power, gas, water, comms and drainage services.

Check local council or strata requirements if edging is installed near a footpath, crossover, easement, retaining wall, shared boundary, or stormwater infrastructure.

Wear full PPE when digging, cutting metal, trimming timber, or compacting material.

Use safe lifting technique for sleepers, concrete edging and pavers.

Keep edging heights and exposed corners safe to avoid trip hazards.

If using chainsaws for related garden clearing, operation and maintenance should align with AS/NZS 2727 and manufacturer instructions.

Maintain safe clearances from irrigation lines and electrical garden lighting.

Step-by-Step Guide

Step 1: Plan the border and choose the edging type

1️⃣ Pick the right edging for the job

Choose edging based on appearance, durability, and ease of installation.

Steel edging is excellent for clean lines, curves, and low-visibility borders.

Plastic edging is budget-friendly and easy for beginners, but lower-end products can distort in heat.

Timber edging/sleepers suit raised borders and natural-style gardens.

Concrete or masonry edging is best for formal gardens and long-term durability.

As a guide:

For lawn-to-garden separation, a visible height of 10–25 mm above soil or mulch usually works well.

For mulch retention, total installed depth often needs to be 75–150 mm depending on bed levels.

For mower-friendly edges, keep the top nearly flush with adjacent lawn where possible.

💡 If you want the neatest low-maintenance result, steel edging on a compacted trench base is often the best balance of appearance and longevity.

Step 2: Set out the line accurately

2️⃣ Mark the shape before digging

Use a string line for straight runs and a hose, rope, or marking paint for curves.

Stand back and check the line from multiple angles before cutting ground. This is where the finished look is won or lost.

Keep curves broad and flowing rather than tight and wavy.

Measure offsets from paths, fences or walls so the border looks intentional.

Confirm finished levels against lawn, garden bed and any paving edges.

For most residential jobs, allow the edging to sit with at least half to two-thirds of its height below finished ground level for stability, depending on product specifications.

Step 3: Check levels and drainage

3️⃣ Make sure water will behave properly

Before excavation, confirm that the edging won’t trap water against the lawn, house, paving or garden bed.

A gentle surface fall of about 1:100 to 1:50 is commonly suitable for surrounding landscaped areas. Avoid creating a dam wall effect with high edging on the downhill side.

If your edging borders paving or a path:

Keep surrounding grades draining away from buildings.

Leave weep paths or low points where needed.

In heavy clay soils, avoid deep trenching that forms a water channel without drainage outlet.

💡 On sloping blocks, step or taper the edging height so it looks level to the eye while still following practical drainage grades.

Step 4: Excavate the trench

4️⃣ Cut a clean trench to the correct depth

Using a spade or trenching shovel, cut along the marked line and remove a neat trench.

Typical trench dimensions:

Depth: 75–150 mm for steel or plastic edging

Depth: 100–200 mm for timber or heavier edging systems

Width: just enough to allow placement, adjustment and backfilling

Keep the trench base as even as possible. Remove roots, large rocks and loose organic material.

For longer or tougher jobs:

A 1.7t mini excavator can help with bed reshaping or bulk spoil removal

For a small edging-only project, hand excavation is usually quicker and cheaper than machine hire once transport is considered

💡 Hire a plate compactor only if you have substantial backfill or long straight runs. For short decorative edging, a hand tamper is usually enough.

Step 5: Prepare the base

5️⃣ Create a stable foundation

Not every edging system needs a crushed rock base, but all edging needs a firm, consistent trench bottom.

For steel or plastic edging, compact the natural subgrade firmly.

For timber, concrete or masonry edging, add 20–50 mm of road base or crusher dust and compact it.

For very soft soil, remove additional loose material and rebuild with compacted base.

Check line and level again with a spirit level or laser.

A stable base prevents future movement, uneven tops, and sections lifting after wet weather.

Step 6: Install the edging sections

6️⃣ Place and align the edging carefully

Install the edging according to the manufacturer’s system.

For steel edging:

Place lengths into the trench

Join sections securely

Tap into final position with a rubber mallet

Install stakes/pins at recommended spacing, commonly 500–1000 mm

For plastic edging:

Avoid over-stretching in hot weather

Stake more closely on curves

Ensure spikes are driven into firm ground

For timber edging:

Use H4 treated timber where in ground contact

Predrill where needed

Fix to pegs or stakes set at regular centres, typically 900–1200 mm

For concrete or masonry edging:

Lay on compacted base

Check alignment continuously

Use concrete haunching if required for stability

Keep checking:

top height

straightness or curve fairness

firmness in the trench

Step 7: Backfill and compact

7️⃣ Lock the edging in place

Backfill both sides of the edging with soil, crusher dust, or specified backfill material.

Compact in layers rather than dumping all the fill at once. This is especially important on the lawn side, where voids can later cause edge movement.

Use hand tamping for small jobs

Use a light plate compactor on longer robust edging runs, avoiding damage to exposed edges

Do not over-compact against lightweight plastic edging, as it can deform

Aim to leave the edging secure with no wobble when pushed by hand.

Step 8: Finish the lawn and garden bed neatly

8️⃣ Blend the border into the landscape

Trim the lawn edge cleanly and top up soil or mulch in the garden bed.

Good finishing details include:

Mulch depth of around 50–75 mm, kept slightly below the edging top

Lawn soil feathered neatly to the edging

No exposed gaps under the edging

Smooth, mowable transitions at path or driveway tie-ins

This finishing step is what gives the project its professional look.

Step 9: Inspect, water and monitor

9️⃣ Check for movement after installation

Once complete, walk the full run and inspect for:

low spots

proud sections

loose stakes

sharp exposed edges

poor drainage points

Water the surrounding soil lightly to help settlement, then recheck after a few days.

Minor touch-ups are normal, especially in newly worked garden beds or reactive clay soils.

Common Mistakes to Avoid

1.Installing edging without calling 📞 Dial Before You Dig (1100) first.

2.Setting the edging too high, creating a trip edge or making mowing difficult.

3.Ignoring drainage and accidentally trapping water in the bed or against paving.

4.Using insufficient stakes or poor fixing spacing, especially on curves.

5.Backfilling loosely without proper compaction, leading to movement after rain.

6.Choosing lightweight plastic edging in high-traffic or full-sun areas where a stronger product would last longer.

7.Using untreated or incorrectly treated timber below ground instead of suitable in-ground-rated material.

Pro Tips

💡 For the cleanest visual result, install the top of steel edging about 10–15 mm above mulch and close to lawn level.

💡 On curves, use shorter edging lengths or systems designed for flexible radiuses to avoid kinks.

💡 If the lawn is couch or kikuyu, choose a deeper edging profile to better slow grass runners.

💡 Compact the trench base before installation and the backfill after installation — both matter for long-term stability.

💡 For projects under 20 m, hire specialist tools rather than buying; for regular landscaping work, buying a quality compactor or laser may become cost-effective.

💡 If you're upgrading multiple landscape elements and equipment purchases exceed $20k, consider speaking with Local Knowledge Finance about equipment finance options.

Recommended Tools

🔧 Recommended Equipment

Cyclone trenching spade — ideal for clean edge trenching in garden beds

Baumr-AG or Spear & Jackson hand tamper — good for compacting short edging runs

Husqvarna plate compactor — useful for longer installations and base preparation

Stabila spirit level or entry-level laser level — helps maintain consistent finished height

1.7t mini excavator hire with mud bucket — worth searching if you’re reshaping beds or doing extensive landscaping beyond simple edging

Frequently asked questions

How deep should garden edging be installed in Australia?: Garden edging in Australia should be installed with 50 to 75 millimetres buried below finished ground level. This depth prevents vigorous runners from turf varieties like Kikuyu and Couch from invading garden beds. Leave 15 to 25 millimetres protruding above the soil surface to retain mulch without damaging lawn mower blades.
What is the best garden edging for Australian soil and weather conditions?: Corten weathering steel and galvanised steel are the most durable options for Australian conditions, resisting UV degradation, termites, and brushcutter damage. Recycled composite edging works best for curved layouts in coastal areas, while H4-treated pine sleepers or extruded concrete kerbing suit straight runs requiring structural soil retention.
Do you need a council permit to install garden edging in Australia?: Standard garden edging under 1 metre in height does not require a council permit on private Australian residential properties. However, if the edging acts as a soil-retaining structure over 1 metre, or alters natural stormwater overland flow paths onto neighbouring allotments, building approvals and engineering certifications apply under local planning schemes.
What are common mistakes when installing landscape edging?: Common mistakes include setting the edging too high above the turf line, failing to anchor stakes at manufacturer intervals, and digging without submitting a Before You Dig Australia enquiry. Overly high edging creates trip hazards and scalp risks for lawnmowers, while inadequate anchoring allows soil pressure to bow the edging line over time.
How do you stop grass runners from spreading under garden borders?: To stop aggressive rhizomatous turf varieties like Couch, Kikuyu, and Buffalo from penetrating garden beds, install edging with a continuous solid barrier extending at least 75 millimetres below ground. Ensure all segment joints interlock tightly, and install a compacted roadbase or crushed aggregate strip directly beneath paver borders.

Written by Digger, the Earthmoving & Landscaping specialist at QLD.Tools.