Most failed lawns don’t fail because of bad turf. They fail because of what happened (or didn’t happen) before the first roll went down.
Skip the preparation, and even good-quality turf will struggle to root. You’ll end up with patchy growth, soft wet patches that never dry out, and ground so uneven the mower scalps it every other pass. At that point, fixing it means starting over.
The good news is that ground preparation isn’t complicated. It takes time and some effort, but do it properly and your lawn will reward you for years. Here’s exactly how to do it.
Why preparation matters more than the turf itself
Turf is living grass. It needs to root into the soil beneath it, and it can only do that if the soil is loose, well-drained, and level. If the ground is compacted, full of stones, or still riddled with old weed roots, the grass has nowhere to go. It sits on the surface, dries out in warm weather, and drowns in wet spells, which in Scotland is most of the year.
Good preparation also gives you a flat, consistent surface. Every bump and hollow you leave now will show up once the turf is down, and they only get worse over time. Getting the ground right before a single roll is laid saves a lot of frustration later.
Step 1: Remove the existing lawn or vegetation
You can’t lay turf over existing grass. The old material underneath will rot, creating a spongy, uneven base that prevents the new lawn establishing properly. Whatever is there now needs to come out first.
For smaller areas, undercutting the old lawn with a spade works well enough. Cut horizontal slices around 5cm deep and roll or stack the old turf to one side. For larger plots, hiring a turf cutter is worth the cost, because these machines do in an hour what would take a full day by hand.
If you’d rather not dig at this stage, a glyphosate-based weedkiller applied to the existing vegetation will kill it back. But allow two to three weeks before you disturb the soil. Laying turf too soon after treatment is a common mistake that people tend to regret.
Step 2: Clear weeds, debris, and stones
Once the old lawn is gone, go through the soil carefully. Perennial weeds like dandelions, couch grass and dock need their roots pulled out completely. Any piece left behind will grow back through your new lawn. It’s a tedious job, but there’s no shortcut that doesn’t come back to bite you later in the season.
Remove stones, rubble, and old roots while you’re at it. As a rough rule, anything bigger than a matchbox is too large to leave in the soil. Smaller grit is fine and will actually help with drainage.
Step 3: Dig and loosen the soil
Compacted soil stops roots penetrating and prevents water draining away. You need to break it up properly before anything goes on top.
Dig or rotavate the ground to a depth of at least 15cm, and ideally 20–25cm if you can manage it. On a large garden, a rotavator earns its hire cost very quickly, and doing this by spade alone across a full lawn is hard going. Once the soil is broken up, rake through it to break down large clumps and catch anything you missed in the previous step.
Check your topsoil depth while you’re at it. You want at least 100–150mm of loose, workable topsoil beneath the turf. If your garden has had building work recently, or you’re on a newer estate, the topsoil is often thin, stripped away, or buried under subsoil. In those cases, bringing in quality topsoil before you go any further isn’t optional, because it’s what the whole job rests on.
Step 4: Improve your soil if needed
Clay-heavy soils are the norm across much of Glasgow, Lanarkshire, and the Central Belt, and they create two problems for new turf. First, water drains slowly, so the surface stays wet for too long. Second, the soil can set almost rock-hard in a dry spell, leaving roots with nowhere to go. Both are manageable if you deal with them at this stage.
If your soil feels sticky and clumps together when wet, work in horticultural grit or sharp sand to improve drainage. Incorporate it across the full cultivation depth rather than just sprinkling it on the surface, because mixing it in properly is what makes the difference.
Sandy or very free-draining soil has the opposite problem. It dries out quickly and holds few nutrients. Working in organic matter (garden compost, well-rotted manure, or a bagged topsoil improver) helps it retain moisture and gives the new turf something to feed on in its early weeks of establishment.
It’s also worth testing your soil pH if you haven’t done so before. Grass grows best at a pH of 6.0 to 7.0. Home testing kits are inexpensive and available at most garden centres. If your soil is too acidic, ground limestone will raise the pH. Alkaline soils are less common in Scotland, but sulphur can bring them down if needed
Step 5: Level the ground
This is probably the most time-consuming part of preparation, but it’s where a good lawn is actually made.
Start by raking the entire area to break down remaining clumps and create a rough level. Then firm the surface (more on that in a moment) and rake again. The aim is a consistent surface with no obvious humps or hollows anywhere across the plot.
Pay attention to the height of the prepared ground relative to surrounding paths, patios, or borders. The soil surface needs to sit around 20mm below paved edges to allow space for the turf itself, which is typically 25–40mm thick once laid and lightly firmed. Get this wrong and your lawn will either sit proud of the paving or drop below it, and neither looks right or mows cleanly.
Step 6: Firm the soil
Once you’re happy with the level, firm the whole area by walking across it in small, shuffling steps. This technique, sometimes called the gardener’s shuffle, presses out air pockets without over-compacting the surface. Cover the area twice, working in different directions each time.
On a larger plot, a light garden roller does the same job more quickly and gives a more even result. Either way, avoid pressing down too hard. You want the soil firm, not compacted, because the difference matters for root penetration and drainage.
After firming, any remaining high or low spots become easier to spot. Rake lightly to correct these, then firm once more. The aim before you lay the first roll is a fine, crumbly surface, what landscapers call a good tilth, with no soft patches or obvious undulations.
Step 7: Apply pre-turf fertiliser and rake in
A pre-turf fertiliser gives the soil a boost of phosphorus and other nutrients that help new roots establish. Scatter it evenly across the prepared surface, and most products recommend around 35–70g per square metre, so always check the packaging for specific rates. Then lightly rake it into the top 25mm of soil so it’s incorporated rather than sitting loose on the surface.
This step is optional but worthwhile, particularly if your soil is on the poor side. The difference in how quickly the turf knits into the ground is noticeable, especially in the first few weeks when the roots are at their most vulnerable.
How long should you wait before laying turf?
Ideally, leave the prepared ground to settle for at least two weeks before the turf arrives. This gives the soil time to compact naturally, lets any remaining weed seeds germinate so you can remove them, and allows the fertiliser to work into the ground. If you’ve applied weedkiller, factor in the wait time on top.
In practice, most people can’t wait that long. If you need to lay sooner, 48 hours is the minimum. Just do a final rake and firm the surface again immediately before the turf arrives, because the ground will have shifted in the meantime.
In Scotland, spring and autumn are the best seasons for laying turf. The cooler temperatures and more reliable rainfall mean new turf can establish without constant irrigation. Laying in summer is possible, but you’ll be watering daily through any dry spell, which is a significant commitment when a Scottish summer can swing from a drought to a downpour in a week.
Once the turf is down and rooting, hold off mowing for around three weeks. When you do cut for the first time, set the mower to its highest blade setting. Cutting too low too soon puts the new roots under stress before they’ve had a chance to anchor properly.
When it makes sense to bring in a professional
Ground preparation on a small area (a back garden patch of 20 or 30 square metres) is entirely achievable as a DIY project given a weekend and the right tools, but larger gardens are a different matter.
On bigger plots, or where the ground has serious problems like heavy clay, persistent waterlogging, significant levelling work, or construction waste buried below the surface, professional preparation will save time, money, and a lot of effort. A landscaper with a rotavator and the right equipment can prepare ground in a few hours that would take a homeowner the best part of a week.
Our team at GGM Landscaping handles turfing and lawn installation as part of our landscaping services across Glasgow and the Central Belt. We take care of the full process, from ground clearance and soil improvement through to levelling and laying, so you get a lawn that’s been prepared and installed properly from start to finish. If you’re thinking about a new lawn or a wider garden makeover in Glasgow, get in touch for a free quote.
Frequently asked questions
Can I lay turf over existing grass?
No. New turf needs direct contact with the soil to root properly. Laying it over old grass creates a spongy, uneven base that rots over time and prevents the new lawn from establishing. Remove the existing grass or vegetation before you start.
How deep should I dig when preparing for turf?
A minimum of 15cm, though 20–25cm is better. Roots need loose, workable soil to grow into. If the ground is compacted below that depth, roots will hit a barrier and the lawn will suffer for it with thin growth, poor drought resistance, and bare patches in summer.
Do I need topsoil under turf?
You need at least 100–150mm of good-quality topsoil beneath the turf. If your garden has had construction work recently, the topsoil is often thin or missing. Bringing in topsoil in these situations isn’t an optional extra, because it’s what allows the grass to root and thrive rather than simply surviving.
How long after weedkiller can I lay turf?
At least two to three weeks after applying a glyphosate-based product. The weedkiller needs time to work through the plant and break down in the soil. Laying turf too soon risks the chemical affecting your new grass during the critical rooting stage.
Is clay soil a problem for turf in Scotland?
Heavy clay soil makes establishment harder because water drains slowly and the surface can become waterlogged through autumn and winter. The fix is to improve the soil before laying, so work in horticultural grit or sharp sand, and consider raising the bed level by 5–10cm if drainage is persistently poor. If you want a lower-maintenance alternative that sidesteps the rooting issue entirely, artificial grass can be a practical option for clay-heavy gardens in Scotland.
Can I prepare the ground in winter?
You can clear weeds and debris in winter, but avoid digging or rotavating waterlogged soil. Working heavy, wet ground destroys its structure and creates compaction that’s difficult to correct. If the soil is saturated, wait for a drier spell before doing the main cultivation work, and the prep will go better and the result will be worth it.