Ash dieback

Ash is the third most common broadleaved tree in Britain.

Ash dieback is a very serious disease of ash trees caused by a fungus called Hymenoscyphus fraxineus which originated in Asia.

It is estimated that Ash dieback will kill around 80% of ash trees across Britain.  It will change our landscape and threaten many species which rely on ash.

If you have an ash tree in your garden you need to be aware of this and you need to be able to recognise the symptoms of Ash dieback.

What does ash dieback look like?

Ash dieback can affect ash trees of all ages. Younger trees succumb to the disease quicker but in general, all affected trees will have these symptoms:

  • Leaves develop dark patches in the summer
  • They then wilt and discolour to black. Leaves might shed early
  • Dieback of the shoots and leaves is visible in the summer
  • Lesions develop where branches meet the trunk. These are often diamond-shaped and dark brown
  • Inner bark looks brownish-grey under the lesions
  • New growth from previously dormant buds further down the trunk. This is known as epicormic growth and is a common response to stress in trees
  • Find out more from the Woodland Trust

Managing Ash dieback if you are a homeowner

The Tree Council has produced useful guidance to help homeowners manage affected trees, while at the same time minimising the ecological impact.

Preventing tree pests and diseases

Tree bio-security has never been more important. We all need to try and prevent future tree diseases such as Ash dieback reaching the UK. 

The key messages are:

  • Don’t risk it: never bring any plants or cuttings back to the UK from abroad
  • Buy safely: Source your new trees carefully. Collect local seed and grow your own trees whenever possible. If you have to buy trees, ensure that your trees have been grown in the UK and that you check the biosecurity policy of the organisation supplying you with trees. Don’t just buy online and hope for the best
  • Clean: Clean shoes before and after visiting a wood
  • Wash: Wash bike wheels to remove mud or plant matter
  • Be vigilant: Report any unusual symptoms on trees to the Forestry England’s Tree Alert system
  • TreeAlert

Contact us

Newark and Sherwood District Council
Castle House
Great North Road
NG24 1BY

01636 650000


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    Castle House
    Great North Road
    NG24 1BY

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