How to spot ash dieback disease

Chalara dieback of ash is a serious disease of ash trees caused by a fungus called Chalara fraxinea Credit: T. Kirisits, Forestry Commission

In October several woodlands in East Anglia were found to have the ash dieback disease, chalara fraxinea. The Forestry Commission has provided a guide on how to spot it:

Symptoms of Chalara fraxinea can include

  • Wilting and black-brownish discolouration at the leaf base and midrib

  • Dieback of shoots and twigs

  • Small lens-shaped lesions or necrotic spots on the bark of stems and branches and enlarge to form perennial cankers

  • Underneath the bark lesions, the wood has a brownish to grey discolouration

  • Trees with withered tops and shoots

  • Heavily affected trees have extensive shoot, twig and branch dieback and often prolific epicormic shoots.

For images of the symptoms click here, and for a further picture guide to chalara fraxinea click here.