Ash dieback Also known as Chalara fraxinea, identified back in 2012, is a serious disease spreading across northern Europe, usually fatal.
Causes
Ash dieback is caused by a fungus (Hymenoscyphus fraxineus)
It is spread by spores from the fungus on fallen leaves, these spores can travel in the wind over many miles.
The movement of ash around the country, prior to the ban, would have likely increased the spread over further distances.
Symptoms
Leaves can appear blackened
Dark lesions on the trunk, often in diamond pattern or long and thin.
Tips of shoots may appear black, shrivelled and wilted.
The stalks and the veins within the leaves may appear brown
In older mature trees you will notice dieback within the crown, bushy newer growth may appear further down the branches.
Summer is the best time to look for these symptoms when the tree is in full leaf, these symptoms can often be caused by other problems so if you suspect it is Ash Dieback you are best to consult an expert.
In order to import fraxinus you must have a plant passport, all imports must be notified to the UK plant health authorities so inspections can be carried out.
For more information on Ash dieback please visit Forestry.gov