Ash dieback key facts

The first cases of the tree disease ash dieback have been found in Leicestershire's National Forest. Trees ranging from five to seventeen years old have been affected at three sites near to Albert Village in North West Leicestershire.

Ash dieback affects more than 550 locations across the UK. Ash forms roughly 15 – 20% of The National Forest tree stock and 1.5 million trees could be affected by the disease.

What is ash dieback?

Tree trunk infected with ash dieback Credit: Gareth Fuller/PA Archive/Press Association Images
  • A chronic fungal disease of ash trees first described by scientists in 2006
  • Trees believed to have been infected by the disease died in large numbers in Poland in 1992
  • It has caused widespread damage to ash populations in continental Europe, including estimated losses of between 60 and 90 per cent of Denmark’s ash trees
  • The disease is now established in many other parts of the UK
  • The disease can be lethal and is particularly destructive of young ash plants, killing them within one growing season of symptoms emerging
  • Older trees may survive initial attacks, but often die after several seasons of infection
  • Unclear whether the disease arrived here by wind borne spores or through infected plant material

Forestry Commission advice and recommendations

Feanedock Wood, one of the forests affected by the fungal disease Credit: ITV Central
  • There is no known cure for the disease
  • No direct action is recommended at infected sites (if diseased trees are felled it will not stop the spores from spreading)
  • Spores are found on decaying leaf stalks and are wind borne
  • Diseased trees should be monitored at the infected sites to identify any symptom-free trees, which may be resilient to the disease
  • Spread of the disease might be slowed by the removal of young infected ash plants

How to spot ash dieback

Common Ash Tree showing symptoms of ash dieback Credit: Gareth Fuller/PA Archive/Press Association Images
  • Spores enter through leaves and cause them to wilt and blacken in colour
  • It leads to the development of lesions in the main stem, preventing the flow of nutrients and water
  • Fungal fruiting bodies appear on fallen leaf stalk material between June and October to release spores and infect more trees

Read more: Ash dieback alert in Leicestershire

Read more: Ash dieback in Dorset