Ash Dieback Disease

Ash dieback is a serious disease of ash trees caused by the fungal pathogen Hymenoscyphus fraxineus (previously known as Chalara fraxinea).

In this section:

• See below: Introduction
• Symptoms of ash dieback 
• Lifecycle of Hymenoscyphus fraxineus 
• Management options when ash dieback is present in an ash woodland
• Research into ash dieback
• Government information and support 
• Legal requirements - ash dieback 

Introduction

Ash dieback is a serious disease of ash trees caused by the invasive fungal pathogen Hymenoscyphus fraxineus (previously known as Chalara fraxinea), which originates in Asia and was brought to Europe in the early 90s. Today, the pathogen covers most of the natural range of ash in Europe causing high mortality rates of ash trees.

Ash dieback was first detected in the Republic of Ireland in October 2012 on plants imported from continental Europe. The disease is now prevalent throughout most of the island of Ireland and is likely to cause the death of the majority of the ash trees over the next two decades.

The disease can affect ash trees of any age and in any setting. The disease can be fatal, particularly among younger trees. Ash dieback is more severe in wet sites, where it is more likely to cause collar infections in ash trees.

Teagasc is carrying out research to establish a gene bank composed of genotypes of ash tolerant to ash dieback with the aim to produce planting stock for forests and hedgerows in Ireland. 

Further information:

• Forestry Division of the Department of Agriculture, Food and the Marine (DAFM), 01 6072651, forestprotection@agriculture.gov.ie 
• Contact your local Teagasc Forestry Advisory Staff