Before You Hire a Landscaper: What Good Groundwork Actually Looks Like
Updated: Sep 16
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 is down and the planting is in, all anyone notices is how it looks. But underneath, there's a whole layer of decisions that determine whether that patio stays flat in five years. It decides if those new shrubs thrive or if you find yourself back out there next spring, wondering why everything has gone wrong.
After studying Horticulture and Design at university, I spent two decades designing and building gardens. Seven years ago, I transitioned to design only. I no longer build gardens; I design them. However, that experience shapes my thoughts on what happens before and during construction. It's often the part clients know least about and the aspect that gets overlooked when time or budget constraints arise.
Here's what I want you to know before hiring someone. I’ll include some rough figures to help you evaluate a quote.
Why Good Groundwork Preparation Matters More Than People Think
Most garden problems that appear later—like a sunken patio, a leaning fence post, or a border where nothing seems to grow—don't stem from bad materials or plants. They originate from 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. Yet, it’s the part that determines whether everything above it behaves as it should.
Protecting the soil where things are meant to grow is often overlooked. It’s invisible and happens early in the process. Heavy machinery and repeated foot traffic compact the soil, squeezing out the air and space that roots need to thrive.
Once compaction occurs in a planting area, it’s genuinely difficult to reverse. You can improve compacted soil, but it takes considerable effort. It's far easier to protect it from the start.
Good practice means keeping machinery, material storage, and foot traffic off any area designated for planting. This consideration should happen before work starts, not after the beds are already flattened. It’s a small question to ask, but it reveals how carefully a contractor is thinking about the entire 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. That base must be compacted in layers, not just dumped in and flattened all at once.
As a rough guide, a patio that only takes foot traffic generally requires around 100-150mm of well-compacted sub-base (commonly MOT Type 1). A driveway that supports a car needs more, typically 150mm or more, and often deeper still on soft or clay ground.
These are general figures, not fixed rules. The right depth for your project depends on your ground conditions. Treat these figures as a starting point for conversation rather than specifications to insist on.
Skip this step or rush it, and the surface may look fine when finished. The trouble tends to show up later, once the ground settles unevenly underneath. By then, it’s a much bigger job to correct than it would have been to do it right the first time.
If a quote doesn’t mention the sub-base depth or material at all, ask the contractor about their intentions.
Choosing the Right Materials
Not every aggregate serves the same purpose. What sits under a driveway needs to behave differently than what supports a path. What works well on light, free-draining soil isn’t necessarily right for heavy clay. A good contractor should explain why they’ve chosen a particular material for your ground and 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 reveals 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 discussed?
That last point matters more than it seems. A verbal answer holds limited value. Getting the figures in writing—even a couple of lines—gives you something to refer back to if things don’t go as expected.
A contractor who does things properly won’t mind being asked these questions. The figures I provided should roughly match what they tell you, allowing for your particular site.
If anything, they’ll likely appreciate that someone is 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 of experience. He works with clients across Lincolnshire, the East Midlands, and beyond. He believes that the best gardens start with listening to the space and the people who will live in it.
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