Larch — the family

Larch — the value exterior softwood

Larch is a softwood that behaves more like a hardwood in service, and it earns its place on value rather than prestige. It’s the timber to reach for when you want the look and weathering of cedar but the budget won’t stretch, or when the job is robust rather than refined — fencing, a shed, a deck, a garden structure that needs to take the weather for a decade without being fussed over.

Its natural durability comes from extractives in the heartwood, the same principle that makes cedar a good outdoor choice. It won’t match cedar for longevity, and it doesn’t have cedar’s low movement or its fine, even texture. What it does have is enough durability to work untreated in many exterior situations, at a price that makes larger projects realistic.

The species under the name

The name “larch” covers several species, and they are not the same timber. In practice you’ll meet three or four, and the differences are real:

• European Larch (Larix decidua) — the traditional European larch. Lighter in colour, moderate in density, moderately durable. The species behind much British-grown larch, and a perfectly good exterior timber, though at the lighter end of the family.
• Siberian Larch (Larix sibirica) — slower-grown in a harsher climate, which makes it denser and harder than European larch, with tighter grain. Older specifications often mean Siberian when they say “larch cladding”, but it is now hard to get in the UK (see the supply situation below), so European larch is the sensible default.
• Japanese Larch (Larix kaempferi) — lighter and less dense than either. Important to know about because a great deal of British-grown larch is Japanese larch or a hybrid of Japanese and European.
• Hybrid / Dunkeld Larch (Larix × eurolepis) — the Japanese × European cross, widely planted in Britain for forestry. Behaves somewhere between its parents; you’ll mostly meet it as British-grown larch in ungraded stock.

The supply situation

Siberian larch is the one to be careful with. Nearly all of it comes from Russia, and the UK has banned imports of Russian wood since 2022, so new stock is hard to find. Belarusian wood was added to the ban in June 2023. Timber still sold under the name may be old stock, or may have been routed through another country, so ask where it was grown and to see the paperwork. For most jobs, European larch is the sensible default, and Douglas fir, western red cedar and thermally modified wood are worth pricing alongside it.

Sources: Herbert Smith Freehills, UK trade sanctions tracker (June 2022); Steptoe, UK expands Belarus sanctions (2023); Earthsight, Russian timber routed through other countries.

One phrase to be careful with: “English Larch”

It isn’t a species — it’s a provenance. If someone says English larch they mean larch grown in England, which is likely to be Japanese larch or hybrid larch rather than European larch. The honest description of the timber is British-grown European larch (or Japanese, or hybrid) — provenance stated, species stated. That’s why this library separates the two ideas rather than treating them as one name.

And the practical warning

Larch moves. It has a pronounced difference between its earlywood and latewood, which makes it dimensionally livelier than cedar, and its grain can be strongly spiral in some stock. That combination means it’s more prone to twisting and checking during drying, and it wants more respect in fixing than cedar does. Cladding fixed tight with no room to move will show it. Cladding fixed with proper ventilation and allowance behind it will settle down and last.

Provenance notes

British-grown larch is a provenance statement, not a species. What’s growing in Britain is mostly Japanese larch and hybrid larch, with European larch in older plantings. So “British-grown” and “European” should never be treated as the same word — the species determines how the timber performs, and where it grew determines the grade and the price.