Why Cedar Earns Its Place in the British Garden

Cedar has a reputation that few other timbers can match, and it is well deserved. The heartwood contains natural oils that repel moisture and resist fungal decay, which means a cedar screen can weather decades of British drizzle without rotting through. It is also remarkably stable, so slats stay straight rather than twisting in the way that cheaper softwoods often do after a wet winter.

There is a practical benefit too: cedar is light. A 1.8 metre screen panel is manageable for one person to lift into place, which is not always true of oak or dense treated pine. Add the warm reddish-brown tone that slowly fades to a soft silver-grey, and you have a material that looks good on day one and arguably better in year five.

Start With the Species, Not the Price Tag

Not everything sold as cedar is the same thing, and the differences matter when you are buying enough timber to screen a boundary.

• Western red cedar (Thuja plicata) is the benchmark for screens. It is light, dimensionally stable, naturally durable and takes an oil finish beautifully. If you see "cedar slats" advertised for garden screening, this is almost certainly what is meant.
• Japanese cedar (Cryptomeria japonica) is denser and slightly stronger, with a straighter grain. It is often sold as sugi. It is durable but heavier, so it suits framed panels rather than free-standing slats.
• Incense cedar is a useful alternative with a fine, even texture and a pleasant spicy scent. It is less common in the UK but worth asking about if your supplier stocks it.
• Cedar of Lebanon and Atlas cedar are specimen trees, not screen material. Their timber is lovely but rarely available in the sizes you need, and the trees themselves are far too broad for a boundary.

Ask your merchant to confirm the species rather than accepting a vague "cedar". The price difference between genuine Western red cedar and a lookalike softwood is significant, and so is the lifespan.

Match the Screen to Your Space and Climate

A screen is not just a barrier; it is a windbreak, a shade-maker and a backdrop. How you build it should follow the conditions on your plot.

In exposed or coastal gardens, a solid, sealed screen acts like a sail and will be torn apart in the first winter gale. Go for a slatted design with roughly 20–30 per cent open area. This slows the wind rather than blocking it, which protects both the screen and the plants behind it. Thicker slats — 20mm or more — and sturdy posts set deeper will pay for themselves.

In small urban gardens, where every centimetre of light counts, a slatted screen filters rather than eliminates daylight. Horizontal slats at 10–15mm gaps give privacy at eye level while letting low winter sun through. In a north-facing or damp corner, raise the screen slightly off the ground on a gravel board or a small gap, so air can move underneath and the base of the timber dries out.

Getting the Dimensions Right

Most British boundary screens sit between 1.6 and 2 metres high. Two metres is the usual permitted maximum for a garden fence or screen without planning permission, dropping to about one metre where it fronts a highway. Check with your local authority before you order, and talk to your neighbour — a screen that improves one garden and darkens another rarely ends well.

For the timber itself, slats of 45–95mm wide and at least 19mm thick strike a good balance between privacy and cost. Wider slats mean fewer of them but more weight and more movement. Posts should be 100mm square or larger, set at 1.5–1.8 metre centres, and fixed with stainless steel screws — ordinary steel will bleed black streaks down the cedar within a season. Leave a small gap between the bottom slat and the ground for airflow.

Finishing and Maintenance

Cedar does not need a finish to survive, but it does need one if you want to keep its colour. Left bare, it will silver within a year or two, which many gardeners actively prefer.

• To keep the warm tone: apply a UV-filtering oil or a pigmented stain every 12–18 months, ideally in early autumn.
• To let it weather: do nothing beyond a soft brush and a rinse with a garden hose each spring.
• Avoid: thick varnish or polyurethane. These trap moisture, crack in frost, and are miserable to strip back.

Treat cut ends and any timber that sits in soil with a brush-on preservative, even on cedar. End grain is where rot begins.

Sourcing, Cost and Long-Term Value

Cedar costs more than treated softwood up front — often two to three times as much for the same dimensions. What you gain is a screen that will not need replacing in eight years, and a surface that ages gracefully rather than turning grey and furry. Look for timber certified as responsibly sourced, and ask whether it is heartwood or a mix that includes paler sapwood, which is far less durable.

Buy a small sample slat first and leave it outside for a month. How it behaves in your own garden, in your own weather, will tell you more than any showroom ever could.