Information on Chalara Dieback in Ash Trees

Information on Chalara Dieback in Ash Trees

Chalara dieback of ash trees has been found in four tree nurseries in England and at three sites which were recently planted with ash trees – at a Forestry Commission Scotland woodland west of Glasgow, at a Leicester car park, and in the grounds of a South Yorkshire college. In all cases it is believed the infection arrived with the young ash plants. Diseased ash plants are being destroyed, and other plants sold from the same consignments are being traced to their final planting sites and destroyed. Surveys are being conducted in the surrounding areas to check whether the disease has spread into ash trees in the wider environment.

In response, The Commission and the Food & Environment Research Agency (Fera) has launched a Consultation on risk assessment for Chalara dieback of ash trees. Views are invited on a Rapid Pest Risk Assessment for Chalara dieback of ash, a highly destructive disease of ash trees which has been found this year in nurseries and recently planted trees in Great Britain.

The risk assessment has been drafted by plant disease scientists at the Forestry Commission’s Forest Research agency. It assesses the risks to the United Kingdom’s ash trees, the feasibility and practicality of eradicating the outbreaks which have been found, and measures to prevent more outbreaks occurring.

Fera are now inviting comments and suggestions on the assessment, and on options for a control strategy. If an eradication strategy is adopted, the risk assessment will be used as evidence to support a case for national legislation to strengthen the UK’s protection from accidental introductions of Chalara fraxinea (C. fraxinea), the pathogen which causes the disease.

The rapid assessment is available to download from the plant pests and diseases consultation pages of the Fera website. The deadline for submission of comments is 26 October, 2012.

Further information about C. fraxinea is available on the Forestry Commission website at

The Forestry Commission has also produced a fact sheet on the disease for download here.


Latest news