Spruce, Sitka (Picea sitchensis)
Sitka spruce is named after a place called Sitka in Alaska.
Common name: Sitka spruce
Scientific name: Picea sitchensis
UK provenance: non-native
Interesting fact: all spruces all have a woody peg at the base of every needle, which helps to identify them.
What does Sitka spruce look like?
Overview: can reach a height of 60m, and have a straight, conical trunk and pointed crown. The bark is purple-grey, developing curved ridges and flaky plates with age. Twigs are light brown and hairless, and the long branches hang downwards.
Leaves: needle-like leaves are straight, flattened and sharp, with two blue-white bands beneath and narrower lines on top.
Flowers: male flowers are oval-shaped, blunt and pale yellow. Female flowers are red, upright and oval, and are rarely seen as they usually grow at the top of the tree.
Fruits: pollinated by wind, female flowers develop into cylindrical, pale green cones, which ripen to a pale creamy-brown in autumn. The seeds within the cones are small and winged.
Look out for: the cones have crinkled and toothed margins.
Could be confused with: Norway spruce (Picea abies). Sitka needles are more harsh and prickly to the touch.
Identified in winter by: in a cross section, the needles are flattened.
Where to find Sitka spruce
The Sitka Spruce has been grown for timber in upland locations since the 1800s. It prefers deep, moist and well drained soils so it tends to flourish in the north and west of the UK on damper and elevated sites.
It is native to coastal areas of northwest America and was introduced to Britain in 1831. It is commonly seen growing in plantations, where it is harvested for its timber.
Value to wildlife
Sitka spruce trees grow close together, forming a dense canopy, so few plants can grow beneath them. The dense foliage does provide cover for larger mammals from the wind and rain, and birds of prey may nest in the branches. Smaller birds such as the crossbill, tree creeper, coal tit and siskin may also use Sitka spruce for nesting.
Mythology and symbolism
In native American mythology, there is a tale of a young man who took up the challenge to twist the trunk of a Sitka spruce tree. He prepared for the challenge by bathing in the ice cold sea and wrestled at night with a stranger wearing bearskin. He won his place as chief of the village, and was rewarded with a Sitka spruce root hat which contained the spirit of a weasel.
How we use Sitka spruce
Sitka spruce is an important timber species in the UK, accounting for around 50% of commercial plantations. The wood is versatile and has a variety of uses from paper making to construction.
Small trees are particularly useful for making paper, while timber from mature trees is used to make boats and ships, pallets and packing boxes.
Sitka spruce can suffer from attacks by the green spruce aphid, which can defoliate the trees and impact growth. The spruce bark beetle can also be a problem in parts of the UK, and trees can also be affected by root and butt rot.