Reading a slope
Why the hardest sites often make the most beautiful gardens — and the four things we check first.
By Marta Oliveira · Verdora Landscape Studio
Clients apologise for their slopes. They should not. A flat site gives you one view and one plane; a sloping one gives you sequence, concealment, level change and the possibility of arriving somewhere. Almost every garden we are proudest of was difficult ground.
What we check, in order
Water. Where does it come from, where does it go, and what is downhill of it? On a slope, drainage is not a detail — it is the thing that decides whether the garden is still there in ten years. We map surface flow before we look at anything else.
Soil depth and type. A slope may have a metre of soil at the toe and 150mm at the crown. That determines what can be planted where, and whether retaining is a wall or an engineered structure.
Existing structure. Failing retaining walls, dying trees holding the bank together, old terracing. What is currently doing the structural work, and what happens when it stops?
Access. Can a machine reach the bottom of the site? The answer changes the build cost more than any material specification. A slope only reachable by hand can double a hardscape budget.
Terrace, or run with it?
Two broad approaches, and the choice is usually made by gradient.
Under roughly 1:6, we prefer to work with the fall — sweeping paths, drifts of planting, no retaining. It is cheaper, it looks more natural, and it drains itself.
Above 1:4, terracing is almost always right. Level ground is what makes a slope usable, and the retaining structures become the architecture of the garden. The middle ground between those figures is where the interesting design conversations happen.
Make the climb worth it
The mistake on terraced sites is treating the stairs as circulation. They are the whole experience. Break long flights with landings, give each landing a reason to stop, and reveal the view in stages rather than all at once from the top.
Stone Stair Garden is 62 treads over an 11-metre rise. It has three landings, and the bay only becomes fully visible at the last one. That sequencing is why people walk it.
The payoff
A flat garden is seen. A sloping garden is travelled. Given the choice, we would take the slope every time.
