Ash Dieback

Please read our information on how we are supporting residents and businesses, as well as information on affected services.


Ash dieback (Hymenoscyphus pseudofraxineus) is a new disease to Britain. It was identified in the UK in 2012. The disease originated in eastern Asia. It was introduced to eastern Europe in 1992 via Poland, Lithuania, Latvia. It then moved through the Scandinavian countries. This disease has had a devastating effect on ash trees across Europe. Some countries have experienced a 95% loss of their ash tree population.

The greatest impact has been in the east and south-east of England. But the disease has now spread to most regions of the UK.  The first confirmed cases in Cornwall occurred in 2014. It has now been identified at locations across Cornwall, and as far west as Penwith. Ash dieback is more widespread in the east and centre of the county. Here some mature ash trees are showing signs of decline. There are parts of Cornwall where the disease has not yet been confirmed. However, it is likely that it will spread to these areas in the next couple of years. 

Recent research by FERA shows that the total cost to the UK public and private sectors is estimated to be £15 billion.  This is in collaboration with The Woodland Trust.

The Forestry Commission produce an interactive map which shows the spread of the disease since 2012. It is regularly updated to show the current situation

What we are doing in Cornwall

Cornwall Council is following the approach used by other local authorities where the disease is more advanced. We are constantly monitoring the development of the disease across Cornwall. 

We are also monitoring trees on Cornwall Council land for signs of the disease. We intend to manage the risk posed by diseased ash with our Tree Risk Management Framework. We are raising awareness within council staff and services, and training officers that attend and manage sites. This will ensure familiarity with the disease and the actions that need to be taken when it is identified.  We have prepared an Ash Dieback Action Plan to manage the growing impact of the disease on our trees and woodlands. This plan will guide our actions on Cornwall Council land and provide guidance to others.

It is important to note that all trees on private land are the responsibility of the landowner. This responsibility extends to the maintenance, felling and removal of diseased trees. Cornwall Council is only responsible for trees on Cornwall Council land. 

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