Ash Dieback Update

Following confirmation of a finding of Ash Dieback (Chalara fraxinea) in Ireland in October 2012 (on plants imported from continental Europe), an ongoing major survey of ash has been carried out by the Department of Agriculture, Food and the Marine. This included targeted and systematic ash surveys of plantations, nurseries, roadsides, landscape and farm landscape plantings and hedgerows. As of 29 October 2013, there have been a total of 101 confirmed finding’s of the disease located throughout the country.

As part of the surveillance effort a systematic survey of Ireland’s hedgerows as well as a targeted survey of hedgerows surrounding infected plantations was carried out. Following confirmation of the first hedgerow infection earlier this month in county Leitrim the Department has now confirmed a second infected ash hedgerow site in county Tipperary. This hedgerow is within 50 metres of a farm landscaping shelterbelt of ash planted 8 years ago with imported plants that have also tested positive for the disease. This is now the second confirmed site of Chalara in a native hedgerow in Ireland. The Department are carrying out a survey of the hedgerow system in the vicinity of this finding before determining the extent of hedgerow to be removed in order to eradicate the disease at this site. In the meantime the farm landscaping shelterbelt is being removed.

Meanwhile the felling of trees in the first hedgerow infection site in Leitrim site has been completed. All ash trees in the surrounding hedgerows and associated leaf litter have been removed and destroyed from a 250m buffer zone around the site.

For further details: see the Department’s press releases (7 and 29 October 2013) below.

What is it?
Ash dieback is a serious disease of ash trees caused by the fungal pathogen Chalara fraxinea (Hymenoscyphus pseudoalbidus). It has spread rapidly across much of Europe. The disease can affect ash trees of any age and in any setting. The disease can be fatal, particularly among younger trees.

What does it look like?
The wide range of symptoms associated with ash dieback includes:

foliage wilt – black/brown leaves may be retained;
shoot dieback with brownish to orange discolouration, often multiple shoots; and,
elongated angular stem lesions, often diamond shaped.

Foliage wilt Shoot dieback Elongated angular stem lesions
Note, symptoms similar to the above may be caused by other factors, e.g. frost.

How can it spread?
Many details associated with the biology of Chalara fraxinea still remain unclear. However, it is likely that plants for planting and wood are pathways for spread over long distances and the disease may be introduced into Ireland through the imports of ash plants and wood, including firewood, from continental European countries.

What to do?
Forest and land owners are asked to be vigilant for the disease and to report (with photographs, if possible) any sites where they have concerns about unusual ill health in ash, to the Forest Service, Department of Agriculture, Food and the Marine: by email (; or, by phone (01-607 2651).

Please do not remove any plant material from a site containing suspect trees. Also, please observe the following hygiene measures on sites where the disease is suspected or where an ash survey is being carried out to help avoid its potential spread:

footwear: wash off all soil and plant debris from boots. Spray your boots with disinfectant and dispose of any used water onto an area where the water will not run into a watercourse;
clothing: check all clothing for any plant material; and,
tools and equipment: wash off all soil and plant debris, and disinfect and dispose of any used water onto an area where the water will not run into a watercourse.
When visiting a forest:
do not remove any plant material from the site; and,
clean clothes and footwear of any plant material, including leaves, before leaving the forest.
Please highlight this serious disease by downloading and displaying this Chalara poster (2.5 MB) in a prominent place.