Please see latest news from the Forestry Commision on the ash disease (Chalara dieback of ash (Chalara fraxinea)
Chalara dieback of ash is a serious disease of ash trees caused by a fungus called Chalara fraxinea (C. fraxinea), including its sexual stage, Hymenoscyphus pseudoalbidus (H. pseudoalbidus). The disease causes leaf loss and crown dieback in affected trees, and usually leads to tree death.
Ash trees suffering with C. fraxinea infection have been found widely across Europe since trees now believed to have been infected with this newly identified pathogen were reported dying in large numbers in Poland in 1992. These have included forest trees, trees in urban areas such as parks and gardens, and also young trees in nurseries.
In February 2012 it was found in a consignment of infected trees sent from a nursery in the Netherlands to a nursery in Buckinghamshire, England. Since then it has been found in a number and variety of locations in Great Britain, including a car park, newly planted woodland and a college campus. All these sites had received stocks of young ash plants from nurseries within the past five years. Further cases have also been confirmed in the nursery trade.
In October 2012, Fera scientists confirmed a small number of cases in East Anglia in ash trees at sites in the wider natural environment, including established woodland, which do not appear to have any association with recently supplied nursery stock. Further similar finds were confirmed in Kent, Essex and other counties in early November 2012.
C. fraxinea is being treated as a quarantine pest under national emergency measures, and it is important that suspected cases of the disease are reported.
Hundreds of staff from government agencies checked ash trees across the UK for signs of the disease during early November. It was one of several actions to emerge from a meeting of the Government's emergency committee, COBR, which Environment Secretary Owen Paterson chaired on Friday 2 November.
Plant health experts are also undertaking a survey of about a thousand sites which have received saplings (young trees) from nurseries where Chalara dieback has been found.
Please see the rest of the information on the Forestry Commisions web site