Before You Hire a Landscaper: What Good Groundwork Actually Looks Like
By Ian Green, Pre-Registered Member of the Society of Garden & Landscape Designers
You can't see most of what makes a garden last.
Once the paving's down and the planting's in, all anyone notices is how it looks. But underneath, there's a whole layer of decisions that decide whether that patio is still flat in five years, whether those new shrubs actually take, or whether you're back out there next spring wondering why everything's gone wrong.
After initially studying Horticulture and Design at University, I spent the next two decades designing and building gardens, before I made the move into design only over 7 years ago. I don't build gardens now, I design them, but that experience is exactly why I still think about what happens before and during construction. It's usually the bit clients know least about, and the bit that gets skipped when time or budget gets tight.
Here's what I'd want you to know before you hire someone, including some rough figures so you've got something to check a quote against.
Why good groundwork preparation matters more than people think
Most garden problems that show up later, a sunken patio, a fence post that's leaning, a border where nothing seems to grow, don't start with bad materials or bad plants. They start with what happened to the ground before anything was built or planted.
Good groundwork preparation isn't the exciting part of a project. There's no photo of "well-compacted sub-base" that anyone shares. But it's the part that determines whether everything above it behaves the way it's supposed to.
Protecting the soil where things are meant to grow. This is the one that gets missed most often, because it's invisible and it happens early.
Heavy machinery and repeated foot traffic compact soil, squeezing out the air and space that roots need to grow into.
Once that's happened in a planting area, it's genuinely difficult to undo. You can improve compacted soil, but it takes real effort, and it's far easier to protect it in the first place.
Good practice means keeping machinery, material storage and foot traffic off any area that's going to be planted, and thinking about that before work starts, not after the beds are already flattened. It's a small thing to ask about, and it tells you a lot about how carefully a contractor is thinking about the whole garden, not just the hard landscaping.
Getting the base right
Any hard landscaping, a patio, a path, a driveway, needs a proper sub-base underneath it, and that base needs to be compacted in layers, not just tipped in and flattened over in one go.
As a rough guide, a patio that's only taking foot traffic generally wants somewhere around 100-150mm of well-compacted sub-base (commonly MOT Type 1), while a driveway that's taking a car needs more, typically 150mm or more, and often deeper still on soft or clay ground.
These are general figures rather than a fixed rule, the right depth for your project depends on your ground conditions, so treat them as a starting point for a conversation rather than a spec to insist on.
Skip this step, or rush it, and the surface might look fine on the day it's finished. The trouble tends to show up later, once the ground has settled unevenly underneath. By then it's a much bigger job to put right than it would have been to do properly the first time.
If a quote doesn't mention the sub-base depth or material at all, it's definitely worth asking the contractor their intentions.
Choosing the right materials
Not every aggregate does the same job. What sits under a driveway that'll take the weight of a car needs to behave differently to what sits under a path that only takes footsteps, and what works well on light, free-draining soil isn't necessarily right for heavy clay. A good contractor should be able to explain why they've chosen a particular material for your ground and your project, not just what it costs.
If the answer to "why this one?" is a shrug, that's a sign to ask more questions.
Questions worth asking before you sign anything
You don't need to become an expert in construction to hire well. A short conversation before you commit tells you most of what you need to know:
• What depth of sub-base are you planning, and why that depth for this project?
• What material are you using, and is it suited to my soil and what's going on top of it?
• How will you protect the planting areas from machinery and material storage during the build?
• Will the sub-base depth, material and any soil protection measures be written into the quote, not just talked about?
That last one matters more than it sounds. A verbal answer is only worth so much. Getting the figures in writing, even a couple of lines, gives you something to refer back to if anything doesn't go the way you expected.
A contractor who's doing things properly won't mind being asked any of this, and the figures above should roughly match what they tell you, allowing for your particular site.
If anything, they'll usually be glad someone's paying attention.
Frequently Asked Questions
Do I need to worry about this if I'm only having a small area of paving done?
Scale doesn't change the principle. A small patio still needs the right depth of sub-base underneath it, and the ground around it can still be compacted by machinery and material stacked nearby. It's just as worth asking about on a small job as a large one.
How do I know if a quote covers proper preparation, or just materials and labour?
Ask the contractor to break down what's included, specifically the sub-base depth and material, not just what's visible at the end. A clear, confident answer with a figure attached is a good sign. Vagueness usually isn't.
Can compacted soil be fixed after the build is finished?
To some extent, yes, through cultivation, organic matter, and time. But it's slow, and some structural damage to the soil is very hard to properly reverse. Protecting it during the build is a far better use of everyone's effort than repairing it afterwards.
Is it reasonable to ask a contractor questions about their process?
Yes, and a good one will welcome it. These aren't awkward questions, they're the kind any experienced professional expects and can answer clearly, figures included.
Does this kind of preparation cost more?
It can add a little to the upfront cost, because the right depth of sub-base and proper compaction take materials and time that cutting corners avoids. But it's almost always cheaper than fixing a failed patio,a settled path, or dead planting a few years down the line.
About the author
Ian Green is a garden and landscape designer with over 25 years' experience, working with clients across Lincolnshire, East Midlands and beyond. He believes that the best gardens start with listening to the space, and to the people who'll live in it.
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