Ash Dieback disease is caused by the Chalara fraxinea fungus. The disease causes leaf loss and crown dieback in affected trees, and it can lead to tree death. It is believed to spread from both nursery transplants and ash wood, consequently imports of nursery stock, firewood and wood for hurley manufacture in particular all pose a threat.
Chalara fraxinea was first confirmed in eastern Europe in 1992 and it has spread westwards since. The disease was found in Britain in Spring of 2011 and first identified in Ireland in a plantation in Leitrim Autumn 2012. To date there have been 39 confirmed findings of Chalara fraxinia in forestry plantations in counties Carlow, Cavan, Clare, Galway, Kildare, Kilkenny, Leitrim, Longford, Meath, Tipperary and Waterford.
Symptoms to look for include necrotic lesions on stems and branches leading to foliage wilt, dieback of branches and death of the top of the crown.