Ash dieback (Chalara fraxinea)

What is Ash dieback?

Ash dieback, Hymenoscyphus fraxineus (also known as Chalara fraxinea), is the most significant tree disease to affect the UK since Dutch elm disease which was first recognised in the 1960s. It will lead to the decline and death of the majority of ash trees in Britain and has the potential to infect more than two billion ash trees (over 1.8 billion saplings and seedlings to more than 150 million mature trees) across the country.

It is an airborne fungus that enters the tree via the leaves and occasionally the stem in young trees. During the summer these will turn black and fall to the ground. The tree then shuts down its water carrying vessels to stop the fungus spreading through the tree. This causes the die back of young and eventually all branches.

Observatree ash dieback identification guide

The Tree Council identification guide

The Tree Council identification guide in larger trees

What are we doing?

ESCC are surveying the county’s roads in 2019 in order to record where ash trees are and what level of infection they are showing. This information will help prioritise any action required, such as felling or further inspections.

Our ash dieback strategy will include working closely with districts, boroughs and parish councils, as well as members of the public who owns ash trees close to public highways.

If you own an ash tree

If you are aware that you have an ash tree on your property, you should be aware of the responsibility you have to ensure it does not become a risk to people or property. Ash trees can decline rapidly once infected and become brittle and weak at the roots, especially if a secondary pathogen attacks the tree.

If your ash are within falling distance of the public highway (which includes footpaths and bridleways) and shows signs of Chalara infection, you may be served with a notice to fell the trees by ESCC Highways who are the local Highway Authority under section 154 of the Highways Act.

If you are unsure whether your tree(s) are infected, you can use the guidance above, or ask a reputable tree surgeon.

Woodland managers and countryside workers

If you own woodland which contains ash you should be aware that:

  1. Markets for lower grade timber are available which may help reduce the cost of felling; and
  2. There are grants available under Countryside Stewardship which can contribute towards the cost of restocking and ongoing management.

For further information on managing your woodland and available grants, and for the contact details of your local Forestry Commission Woodland Officer please visit The Forestry Commission’s website.

For guidance about biosecurity, cleaning tools and equipment, see:

Countryside visitors and householders

The risk of spreading the disease by visiting a forested area is very low, but you can help by following advice from the Forestry Commission website – Advice to forest visitors.

Contact us

For more details on ash dieback, contact our Dutch Elm Disease Officer.