What Your Garden Is Trying to Tell You: The Science Beneath the Soil
1 October 2026
When something isn't quite right in a garden, our first instinct is often to look at what we can see.
A lawn starts developing bare patches, so we add grass seed. A shrub isn't growing, so we feed it. A border struggles, so we replace the plants.
Sometimes that works.
But sometimes the real problem is happening beneath your feet.
After seven years working in gardening, one thing Jordan has learned is that a garden will usually give you clues about what it needs. Standing water, moss, cracked ground, yellowing leaves and plants repeatedly failing in the same location can all tell us something about the conditions below the surface.
And understanding those conditions can make the difference between continually fixing a garden and actually helping it thrive.
Not All Soil Is the Same
Soil might look fairly simple, but its structure has a huge influence on how a garden behaves.
The main mineral particles found in soil are clay, silt and sand, and the size of those particles varies enormously. Clay particles are less than 0.002mm across, while sand particles range from approximately 0.05mm to 2mm.
That microscopic difference has very visible consequences.
Clay soils contain extremely fine particles packed closely together. They tend to retain water and nutrients well, but can become heavy and wet during winter before drying hard during warmer weather. The RHS classifies soils containing more than 30% fine clay particles as clay soils.
Sandy soils behave almost in the opposite way. Their larger particles create bigger gaps through which water can move, meaning they generally drain quickly and warm relatively rapidly, but can also lose water and nutrients more easily.
Then there is loam – a mixture of clay, sand and silt which tends to avoid some of the extremes associated with the individual soil types.
So when somebody says a plant is "easy to grow", there is an important second question:
Easy to grow where?
Surrey Is a Perfect Example
This is particularly relevant to us because Surrey has surprisingly diverse geology.
Across the county there are areas associated with clay, sand and chalk formations. The North Downs, for example, are strongly associated with chalk, while other parts of Surrey sit over formations including London Clay, Lower Greensand and Weald Clay.
That means two Surrey homeowners can experience completely different problems.
One garden might remain wet for long periods after heavy rainfall.
Another might drain extremely quickly and require more attention during prolonged dry weather.
A garden on chalky ground might also have more alkaline conditions. The RHS defines chalky soils as having a pH of 7.1 or above, and certain acid-loving plants – including rhododendrons and camellias – can struggle in these conditions.
That's one reason we don't believe gardening should simply involve applying the same routine to every property.
The garden itself should influence the approach.
Why Does Water Sit on My Lawn?
A puddle doesn't necessarily mean you've simply had too much rain.
Persistent surface water can be a sign of poor drainage or soil compaction.
Healthy soil contains pores – tiny spaces between particles that can contain both air and water. When soil becomes heavily compacted, those spaces can be reduced, making it more difficult for water to travel through the ground and for roots to access the air they need.
Think about the areas of a garden that receive the most traffic.
A route repeatedly walked across.
The area around a gate.
Ground underneath children's play equipment.
A lawn regularly crossed to reach a shed.
Over time, those areas can behave differently from the rest of the garden.
The RHS notes that surface puddling after rainfall can indicate compacted layers beneath the surface. One way of investigating drainage is to dig a hole roughly 30–60cm deep, add water and observe how long it takes to disappear. Water remaining for hours or days can indicate a drainage problem requiring further investigation.
The important point is that installing drainage isn't automatically the first answer. In some established beds, relieving compaction and improving the soil may be sufficient.
Your Plants Are Talking Too
Plants can also reveal information about their environment.
A plant repeatedly struggling in one particular part of the garden doesn't necessarily mean there is something wrong with the plant.
It could be receiving:
too much or too little sunlight;
too much water;
insufficient moisture;
unsuitable soil conditions;
excessive exposure to wind; or
conditions that don't suit its preferred soil pH.
Soil pH measures how acidic or alkaline the ground is. A pH of 7 is neutral, numbers below 7 are acidic and those above 7 are alkaline. Different plants perform best within different pH ranges.
This is why simply replacing a struggling plant with another example of exactly the same plant can sometimes produce exactly the same result.
Good gardening involves asking why it struggled in the first place.
The Surprising Importance of Air
We naturally associate plant growth with sunlight and water, but roots also need access to oxygen.
When soil becomes waterlogged, water fills the spaces that would ordinarily contain air. Prolonged waterlogging can therefore prevent roots from receiving sufficient oxygen.
This is also why more water isn't always better.
Wilting plants are often associated with dry conditions, but struggling roots in excessively wet ground can create problems of their own.
The aim isn't simply to give a garden as much water as possible.
It's to create the right balance.
Most Roots Aren't as Deep as You Might Think
Another interesting fact is just how much activity happens relatively close to the surface.
According to the RHS, plant roots are mostly found within the top 50cm of soil.
That makes the condition of the upper layers of a garden particularly important.
Compaction, poor soil structure and repeated disturbance can directly affect the area in which much of a plant's root system is trying to establish itself.
It's one of the reasons soil preparation before planting can matter just as much as the plant you eventually put into the ground.
Why Organic Matter Matters
One of the most useful tools in gardening isn't particularly glamorous.
It's organic matter.
Materials such as well-rotted garden compost, leaf mould and well-rotted manure can help improve soil structure.
And interestingly, organic matter can be useful at both ends of the drainage spectrum.
In lighter soils it can help retain moisture and nutrients, while in heavier soils it can improve structure and drainage.
The RHS notes that gardeners will typically aim to maintain soil organic matter at around 3–6%, although what an individual garden requires will depend on its existing conditions.
So improving soil isn't necessarily about endlessly adding fertiliser.
Sometimes improving the physical structure of the soil itself is more important.
And Sometimes the Best Thing You Can Do Is Nothing
Gardening is also about knowing when not to work the ground.
Heavy clay soil is particularly vulnerable when extremely wet. Walking across or working wet clay can damage its structure and increase compaction.
That's why experience matters.
There are occasions when getting a job done immediately isn't necessarily the best thing for the garden.
Waiting for better conditions can produce a better long-term result.
Look Before You Treat
This all leads to one of the simplest principles we use when looking after gardens:
Don't just treat what you can see. Work out why it's happening.
If part of a lawn constantly becomes waterlogged, there's probably a reason.
If the same border dries out every summer, there's probably a reason.
If plants repeatedly fail in one corner of a garden, there's probably a reason.
And finding that reason can prevent homeowners spending money repeatedly treating the same problem.
At JPT, our approach to gardening is built around observation, practical experience and understanding the individual garden in front of us.
Jordan brings seven years of hands-on gardening experience, giving him an understanding not simply of how to carry out garden maintenance, but of how gardens change through the seasons and how different areas respond to different conditions.
We believe a great garden isn't created by forcing every outdoor space into the same formula.
It's created by understanding what you already have – and working with it.
Sometimes the most important part of your garden is the part you can't see.