St Nicks

Centre for nature and green living

November 2015: Spotlight on … Ash trees

Ash "keys"

Ash “keys”

Ash (Fraxinus excelsior) is a native tree, but it’s one on its own. It belongs to the Oleaceae, along with the Olive and Lilac, and its only native relation is a form of wild Privet. Two or three Mediterranean and American forms have been introduced as ornamental trees, but you’re unlikely to find them outside parks and large gardens.

Ash flowers

Ash flowers

If you can’t confidently recognise it, now is a good time to look for it. No other British tree has matt black buds on smooth, greyish twigs. The buds are arranged in opposite pairs with a single one at the tip, and the twigs are slightly flattened just beneath the buds. In spring, look out for the beautiful dark purple-red flowers. They open well before the leaves, but it’s surprising how few people seem to notice them. Reputable sources differ in points of detail, but it seems that trees can vary in producing male-only, female-only and bisexual flowers, or different permutations on the same tree.The leaves are composed of leaflets, again with one at the tip of the stem and the rest in opposite pairs. The fruits are winged seeds that hang in dense clusters right through winter. Young trees have smooth bark which becomes increasingly ridged as they age.

Ash leaves

Ash leaves

Environmentally, it’s a useful tree because its canopy lets dappled light through, allowing other plants to thrive underneath. Bullfinches are said to enjoy its seeds, and reports suggest that in the region of a thousand species ranging from birds to lichens are directly associated with Ash. This of course means that the threat from Chalara, the Ash die-back fungus, is serious for much more than just the landscape. The disease has dropped out of the headlines, but is steadily spreading – perhaps because, unlike Dutch Elm disease, it tends to kill saplings faster than mature trees. So the line of defence is to preserve older trees for as long as possible, while trying to identify resistant strains to propagate. There is a real threat to St Nicks’ young trees, but any surviving an outbreak could be nationally important.

The botanical name excelsior is Latin for loftier, more elevated – presumably reflecting the fact that a mature Ash normally grows to between 20 and 25 metres, but in a really favourable situation is said to be able to reach as high as 45 metres. Fraxinus is simply Latin for an Ash tree, though the Romans also used it as a poetic word for a spear with an ash wood shaft. Young Ash branches, particularly when coppiced, grow straight, strong and flexible, so it’s hardly surprising that the Anglo-Saxons also used them to make spears, and they too used æsc (the ancestor of our word) as a poetic term for spear. The qualities of the wood that made it good for spears have kept it in use for items that need resilience – wooden ladders, hockey sticks and handles for tools.

Important native trees often come with a lot of folklore, and Ash is no exception. There are various (and contradictory) versions of a weather rhyme based on when the leaves come out: “Oak before Ash, only a splash; Ash before Oak, in for a soak”. In Norse mythology, the first man was formed from an Ash trunk, and the great tree Yggdrasil that connects the worlds of the cosmos is usually identified as an Ash. A serpent gnaws its roots, and when the tree finally dies, the present cosmic cycle comes to an end. Maybe we should be even more worried about Ash die-back!

Source and further information on Ash die-back:

19 November 2015 | Categories: Spotlight on... | Tags: ash, ash tree, tree