What can save Britain’s ash trees?

The next time you drive or walk down a country road, you may well notice that something is not quite right. Look around and you might see that tall ash trees in the verge-side hedgerows are no longer as handsome, their leaves sparse and scattered, even brown and wilting, while naked branches point accusingly to the sky. A disaster is unfolding, which, on the face of it, seems hardly less serious than the one that hit the countryside in the early 1970s, after ‘Dutch’ elm disease was imported in timber from Canada and killed 30 million trees. This time, the victim is the European ash (Fraxinus excelsior).

Hymenoscyphus fraxineus is a fungus indigenous to Asia, where ash species tolerate it, because pathogen and trees have evolved together. The fungus arrived in Europe 30 years ago.