Ash die back disease (Chalara fraxinea) is the latest in a host of diseases to affect our native trees. It appears from the rapid spread across the continent (first recognized in Poland in 1992) that this pathogenic fungi has now taken a hold in the UK with a total of 413 confirmed cases as of 18 March, predominantly in the east of England.
- die back from the tips of trees, most visible when in leaf
- lesions and cankers on stem branch and twigs, visible throughout the year
- leaves die back from mid-summer leaving black or brown leaf stalks
- wilting of leaves in spring and early summer
- crown dies back from the tree tips
- tiny fungal fruiting bodies can be seen on leaf stalks in June/July
- Excision of affected stems reveals dark stains.
What you should do if you notice any of these symptoms: firstly, don’t panic, there may well be other explanations, and if it does turn out to be Ash die back affecting your tree it may not sound the death knoll for the tree, as some trees have a natural resistance to the disease and not all trees die from infection. But as with any other tree problems, assess the safety of the tree first, track the progress of the symptoms and prune or fell where branches threaten to cause significant harm. Where practical, collecting and burning leaf litter in autumn will help limit spread of the disease.
Movement restrictions are in place on infected material and it is good practice for those working on any potentially diseased tree to sterilize equipment after use to limit potential cross infection.. Tree professionals and the general public are helping to track the spread of the disease by reporting symptoms to Forest Research. This can be done via their website where you can fill in and submit a form or download an app for your phone. Much more detailed information as available on the Forestry Commission website at www.forestry.gov.uk/chalara.