How to Prepare Soil for a New Lawn
Creating the ideal foundation for your new lawn to thrive.
A cracking lawn doesn’t start with turf rolls – it starts underneath them.
If you want your new lawn to actually thrive (not struggle, thin out, or turn into a weedy mess), proper soil preparation is non-negotiable. Get this step right and your turf will establish faster, root deeper, and cope far better with heat, wear and Aussie conditions.
Let’s walk through how to prepare soil for new turf – the right way.
Why Soil Preparation Matters
Before laying a new lawn, the ground needs to be:
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Free of weeds
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Well-drained
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Level and smooth
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Packed with the right soil mix
Skipping prep can lead to poor drainage, compacted soil, weak roots and patchy growth – and fixing it later is far harder (and more expensive).
Tip: Always make sure the soil slopes gently away from house slabs, paths and retaining walls so water doesn’t pool where it shouldn’t.
Clear Weeds and old grass
First things first – everything growing there now has to go.
Use a non-selective herbicide to kill all weeds and existing grass in the area to be turfed. Even if you’re removing old turf, weeds can still be lurking below the surface.
How to Remove Weeds Properly
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Use a glyphosate-based herbicide (such as Round-Up)
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Spray evenly across the area
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Allow 7–10 days for weeds to fully die off before disturbing the soil
Cobbitty Turf stocks a full range of weed killers and herbicides if you need them.
Excavation and Soil Improvement
Once weeds are dead, it’s time to look at what you’re actually working with.
New builds in particular often have heavily compacted soil, rubble, or poor-quality fill that turf simply won’t like.
Improving Different Soil Types
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Clay soils:
Apply gypsum before rotary hoeing to help break up compaction and improve drainage. -
Sandy soils:
Mix in organic matter, compost or coco peat to improve moisture and nutrient retention.
This step makes a massive difference to how well your lawn establishes long-term.
Turf Underlay
A quality turf underlay gives your new lawn the best possible start.
Rotary hoe the area, then spread a good quality turf underlay with roughly:
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70% sand / 30% soil
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Laid to a depth of 50–100mm
This creates a free-draining, nutrient-rich base that turf roots can quickly grow into.
How Much Soil Do I Need?
You can easily calculate how much soil is required using this formula:
Area (m2) x Depth (m) x 1.6 = Tonnes of soil needed
Example:
65m2 x 0.05m (50mm) x 1.6 = 5.2 tonnes of soil
You’ll already know your area when ordering turf – just plug the numbers in.
Rake the Area
Rake the soil to a fine, smooth finish, removing any lumps or dips.
When laying turf against paths or edging, keep the soil level 30–40mm below the finished edge height to allow for turf thickness.
This is also the best time to check drainage – water should run away easily, not pool.
Apply Starter Fertiliser
Before laying your turf, apply a quality starter fertiliser to encourage fast root growth.
We recommend Sir Launcher fertiliser, applied at:
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3kg per 100m²
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Or 900g per 30m2
Rake it lightly into the top 30mm of soil.
What Is Sir Launcher?
Sir Launcher is a premium water-saving starter fertiliser with a nutrient accelerator designed to:
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Promote strong root development
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Help turf establish faster
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Improve early drought resistance
Sir Launcher is available from Cobbitty Turf when you place your turf order.
Ready to Lay Your New Lawn?
Once your soil is prepared, levelled and fertilised, you’re ready for the fun part – laying turf.
If you’re unsure about soil prep, quantities, or the right turf for your conditions, the Cobbitty Turf team is always happy to help. After all, we’ve been growing lawns for over 30 years – and we’ve seen just about every soil mistake under the sun.
Get the prep right now, and your lawn will thank you for years to come.
