Ash dieback

A highly infectious fungal disease known as ‘Ash dieback’ or ‘Chalara’ is threatening to wipe out all species of ash trees, including our native ash (Fraxinus excelsior). Ash trees are valuable features of Devon’s landscape and are present in our native woodlands and hedgerows. Both native and ornamental ash trees are present in parks and gardens.

Cases of the disease are now confirmed in many English counties, including Devon. View the latest information from the Forestry Commission including a map that is updated weekly, showing the location of confirmed cases in the UK. There is also information on how to recognise signs of the disease in ash trees.

As an emergency measure to control the spread of the disease, the import and movement of ash seeds, plants and trees in the UK has been prohibited since 30 October 2012 under the Plant Health Order 2012. Legally enforceable action can therefore be taken to control the spread of the fungus when it is found.

Devon County Council fully supports the Defra Chalara Management Plan.

The plan objectives, which were set out in the December 2012 interim Control Plan, remain the same. These are:

  • reduce the rate of spread of the disease
  • develop resistance to the disease in the ash tree population
  • encourage landowner, citizen and industry engagement and action in tackling the problem
  • build economic and environmental resilience in woodlands (and other non-woodland trees) and in associated industries.

The management plan predicts the ‘risk of infection by 2017’ as low for Devon. It is believed that the disease has spread from the continent by air and therefore south-east England has high and medium risk of infection. Devon is classed as having a high ‘hazard value’ due to the high amount and value of ash in the county. These two measures combine to class Devon as a ‘high priority area’ where interventions, such as removing young infected plants, are most likely to be cost effective. Therefore, Devon is one area where Defra and the Forestry Commission inspectors are focusing their efforts by tracing recent deliveries of young ash trees and checking for signs of infection.

The Forestry Commission has produced an advice note on ‘Managing Chalara dieback of ash in South West England’ This provides a useful source information to guide the actions taken by all those involved in the care and management of trees and woodlands.

Ash dieback looks set to have a major impact on Devon’s countryside, much of which is defined by its rich networks of hedges. Ash is one of our three main hedgerow trees, along with oak and beech, and makes up about one sixth (16%) of their shrubby growth. If the ash goes, and evidence from the continent suggests we will lose 90% of them, then our landscape will change dramatically.

What you can do

  • Exclude ash (Fraxinus sp.) from landscape planting schemes to be implemented this planting season and substitute other native / locally appropriate trees
  • Check ash trees in land under your control for signs of the disease and report all suspected cases to the Forestry Commission
  • If you suspect a case of ash dieback, please:
    • take photos of the ash tree/s. Good photos and detailed information are very important to help Forestry Commission staff diagnose the disease and they may visit suspected cases
    • fill in the online Forestry Commission Tree Alert form
    • use the Forestry Commission Tree Alert form apps for Android or iPhone.