Chalara dieback of ash (Hymenoscyphus fraxineus) Ash Dieback
Chalara dieback of ash, also known as Chalara or Ash Dieback, is a disease of ash trees caused by a fungus called Hymenoscyphus fraxineus. The fungus was previously called Chalara fraxinea, hence the name of the disease Ash Dieback.
Ash Dieback was first identified in Poland in 1992. Since then it has spread across Europe with Norway, the Netherlands, Germany and Denmark particularly affected. In Denmark it is reported that some 90% of their Ash trees may have been killed or been infected by the fungus which causes Ash Dieback. It has now been identified in areas of Kent. In my travels around Kent I notice Ash Dieback symptoms from Maidstone to Ashford and Dover.
Top ten tips for dealing with Ash dieback https://www.abouttrees.co.uk/ash-dieback-top-ten-tips/
In the UK evidence of Ash Dieback was found early in 2012 in tree nurseries and sites recently planted with young Ash trees. However it was not until October that the disease was found in established trees, in East Anglia. A recent survey has now revealed affected trees in Kent. It is widely accepted as being un-treatable and could potentially see the demise of 90million Ash trees.
Chalara causes leaf loss, crown dieback and bark lesions in affected trees. Once a tree is infected the disease is usually fatal, either directly, or indirectly by weakening the tree to the point where it succumbs more readily to attacks by other pests or pathogens, especially Armillaria fungi, or honey fungus.
The presence of Ash Dieback does not make an infected tree any more hazardous or likely to fail. It can take a number of years to kill a mature tree and there is small evidence of a natural resistance amongst the Ash population. We don’t yet know what the full impact of Chalara will be in Britain. Evidence from continental Europe suggests that older, mature ash trees can survive infection and continue to provide their landscape and wildlife benefits for some time.
It will be difficult over the winter months to assess whether trees have been infected as the most obvious visible symptoms affect the leaves. However, if you are concerned about your trees please email your name, address and a contact telephone number to ashdieback@abouttrees.co.uk our arborist will be able to visit the site and offer advice on current best practice for managing affected trees.
Additional information, including guidance on how to identify Ash dieback and how to formally report suspected outbreaks is available on the Forestry Commission website: http://www.forestry.gov.uk/chalara
