16 Dec What Tree? Yew

Yew (Taxus bacatta)

Arguably the most recognisable evergreen tree in the UK, the yew is commonly associated with churches and places of religious significance.  The Fortingall Yew in Perthshire is considered to be the oldest tree in Britain, with its age estimated to be anywhere between 2,000-5,000 years old.  Closer to home, the yew tree at St Mary the Virgin Church in Oxford is thought to be at least as old as, if not pre-dating, the Norman church itself.

The association between Yew trees and churchyards, while romantically ascribed to the healing and magical powers of the tree, is more prosaically due to its toxicity acting as a means of deterring livestock from disturbing graves.

Appearance and Identification

Yew can grow up to heights of 25m, although it more commonly only achieves lower heights. William Mutch describes it as “A low growing evergreen tree up to 20m, densely branched.” (Tall Trees and Small Woods).  Yew is considered to be a slow growing tree, but when planted as a young tree, the initial growth can be quite rapid although it does slow dramatically with age.

Identification of Yew from its leaves, bark and fruit is relatively straight forward.  The leaves are approximately 3mm in length, found in sprays of upto 30 on each shoot.  The flattened leaves are arranged in a spiral form along the length of each twig.  Mature leaves are deep green in colour, making the tree stand out in winter months, but in spring, new growth is very light green in colour and soft to touch.  This lightness of colour and touch remains for upto three years before hardening and darkening.

The species is dioecious, meaning separate male and female trees are required for fertilising the flowers in spring.  The fruit appears in autumn months, visible by its characteristic red berries, the soft sweet flesh of which covers a highly toxic seed.

The bark of the tree is described as rust red, often flaky and peels easily as it ages.

The bark and winter buds of the tree can be mistaken, on first glance, for walnut.  The bark is often smooth and dark grey with slightly corky ridges that give a slightly snake like appearance, but it is the winter buds that can cause the most confusion.  The heart shaped leaf scars have a very strong resemblance to walnut leaf scars, with a large heart shaped  scar (also described as looking like a monkey face) on the twig.  Small reddish domes buds grow just above this scar.

Propagation & Control

Yew is a highly shade tolerant species and is best grown in sheltered locations on a limy loam soil although it will grow on clay.  It is also highly tolerant of pruning and clipping making iy a fine choice of tree or shrub for topiary.  There are six species of Yew in the UK, with the fastigiate form being the Irish Yew, and a more ornamental form in Golden Yew.

There are very few pests and diseases that have an impact on yew, perhaps explaining its longevity.  Chicken of the woods (Laetiporus sulphureus) is one such fungi, primarily affecting roots, buttresses and the main stem, causing the tree to hollow out.  The relationship is not necessarily fatal, and yew can survive for centuries when colonised by Chicken of the woods.

Source and reference materials

Information detailed in this post has been obtained from the author’s own knowledge and photographic library where possible.  Additional sources of information and photographs include:

Johnson, O & More, D (2004) Tree Guide: The most complete field guide to the trees of Britain and Europe. Collins.

Mutch, W (1998) Tall Trees and Small Woods. Mainstream Publishing

Watson, G & Green, T (2011) Fungi on Trees.  The Arboricultural Association

Images:

Woodlandtrust.org.uk (Yew leaf)

WildfoodUK.com (Yew berry)