Why does cedar turn red???

Red cedar is a high yielding productive species, which grows well on lowland sites in South Scotland. On such sites, we would tend to plant a combination of different productive species.

Sitka spruce tolerates high DAMS scores, even if the wind is salty- so is an excellent choice for the upper slopes. On the steeper, mid-slopes, Douglas fir is a good choice, as long as it is not too exposed. On the slightly damper, lower slopes, red cedar is one of our key choices.

Between these three species, they produce the full range of softwood timbers. Spruce produces general purpose carcassing, whilst Douglas fir can produce premium construction timber. Redwood can produce superb, durable timber, for uses such as cladding and glass house framing- where it can last over 100 years without treatment. As a result, red cedar timber (normally imported) is in strong demand and is an expensive product.

Like Douglas fir, red cedar is best managed through thinning, with longer rotations to maximise the proportion of heartwood and processed by specialist mills.

As a later succession species from the Pacific North West (found alongside Sitka spruce and Douglas fir), it is also very shade tolerant. This means that it could play an important role in natural regeneration within forests.

We have found that it establishes well. However, many are surprised by the unusual winter colour. Indeed, it often looks as though the trees have died.

So why do they change colour from vibrant green to reddish brown?

Apparently, at low temperatures, the enzymes required for photosynthesis are not active and the excess light energy (even in Scotland) can cause cell damage. As a result, red cedar has evolved its own internal 'sun-screen' to protect it during dormancy. This is called Rhodoxanthin and is a xanthophyll carotenoid.

This effect is only found in the 'sun leaves' of younger trees and in the spring, the trees revert to their vivid green.

Red cedar is revered by many indigenous North Americans because of the range of materials which it can provide. Indeed, some tribes developed techniques to harvest the heartwood, without killing the tree, such was its importance. The timber, branches and bark were used to produce a range of products such as rope, fishing line, clothing, baskets, buildings, totem poles and canoes.