Other symptoms include withered and blackened leaves (above). The small, white fruiting bodies, or fungi, may be seen on infected leaf stalks during the autumn.

Ash (Fraxinus excelsior, above) is a native British tree, and is the UK's third most abundant broadleaved tree species, with an estimated population of 126 million trees.

Ash Dieback symptoms include bark lesions (above) and crown dieback, leading to tree death. 80-99% of our ash trees may die from the disease within the next 20 years or so.


Ash Dieback is caused by a fungal infection, now known as Hymenoscyphus fraxineus  (aka H. pseudoalbidus, or Chalara fraxinea).  Ash Dieback is a serious tree disease and has moved across Europe since the early 1990's, decimating ash tree populations. This website aims to explain what Ash Dieback is and its likely impact in the UK. It also links with other useful websites, giving timber movement rules, research findings and management policies