Ash dieback

Ash dieback is a serious disease of ash trees caused by the fungus Chalara fraxinea.

The disease causes leaf loss and crown dieback in affected trees and it can lead to tree death. Chalara fraxinea is being treated as a quarantine pest and it is important that suspected cases of the disease are reported.

Planning conditions

Landscaping conditions frequently require the planting of trees as a form of mitigation. As a locally abundant and characteristic species, ash is frequently specified for planting schemes. However under a Plant Health Order the movement of ash planting stock has been banned.

Until further notice none of the ash species should be specified for planting in any scheme that is submitted to us. No scheme which proposes the planting of ash will be approved. Existing approved landscaping schemes that include ash cannot be fully implemented because of the ban on ash nursery stock. It is not practical to recommend an overall substitute species for all schemes because each site and its conditions will vary. It may be appropriate to merely increase the proportions of other species in the scheme.

Providing that the overall strategy and impact of the scheme remains substantially similar, an amendment which proposes a change of species from ash to another may be considered of minimum importance. In this situation, applicants or their agents are advised to contact us outlining the proposed changes and seeking agreement that the scheme may proceed.

If we consider that the changes are significant, an application will need to be made seeking consent to modify or vary the approved scheme.

Tree Preservation Orders and trees in Conservation Areas

it is considered unnecessary to fell healthy ash trees and applications for consent to fell unaffected trees will be judged on their merits as normal. The potential for infection by Chalara fraxinea will not be a significant consideration.

Applications for consent to fell trees which are confirmed to be infected will be judged on their merits with consideration of the likely outcome of infection and the benefits of disease control.

Dead or dangerous trees

Certain exceptions are made for the removal of dead trees and branches, or the removal of trees and branches that pose a significant and imminent risk. We advise you to contact us about plans to work on such trees unless the situation is so dangerous that it would be unacceptable to do so.


Notification should be made as soon as the problem becomes apparent and a minimum of five working days before the works take place. We will respond in writing confirming whether the works may proceed. 

New Tree Preservation Orders

The potential risk of infection will not be considered a significant justification for not making a TPO. A confirmed infection is likely to be a significant factor against making a TPO. Each case will be judged on its merits and influenced by current national guidance. A tree with a Plant Health Order against it would not be made the subject of a TPO.