Ash dieback in Bucks, Berks and Oxfordshire

Maidenhead Thicket - Hugh Mothersole

Along with many other organisations, we're concerned about ash dieback, a fungal disease that's affecting many woodlands, parks and gardens across the country. We're doing all we can to manage the disease in Bucks, Berks and Oxfordshire, which includes felling dead and dying trees for safety.

There are an estimated 80 million ash trees in the UK, helping to shape some of our best loved landscapes. They make up a third of our entire tree population. It's thought that over 90% of these trees will be lost to the disease, having a devastating impact on the countryside and biodiversity of our woodlands. 

Ash trees are a common feature in the woods as well as in the wider landscape of Bucks, Berks and Oxfordshire. Sadly, ash dieback is now present in most of the woodlands we manage in the region.

young ash or rowan tree
young ash or rowan tree
young ash or rowan tree

What is ash dieback?

Ash dieback, Chalara or Chalara dieback is a disease that affects ash trees and is caused by a fungus called Hymenoscyphus fraxineus. The disease originated in Asia and its spread is attributed to the movement of plants as part of the global trade. The fungus spreads quickly as its spores are windborne. 


Ash dieback can affect ash trees of all ages, although younger trees succumb to the disease much quicker. As the name suggests, the disease causes ash trees to slowly die, drop limbs or branches, collapse or fall.

Signs of the disease include;

  • Leaves developing dark patches in the summer. They then wilt, turn black and begin to fall to the ground
  • Dark brown lesions develop where branches meet the trunk
  • Shoots, especially those on the crown dieback during the summer

Once a tree is infected the disease is usually fatal. There is no cure, but some trees are less susceptible than others.

Maidenhead Thicket in winter
Maidenhead Thicket in winter
Maidenhead Thicket in winter

Restricted access and diversions

There may be temporary road closures and restricted access along some routes and pathways during these essential works. Where this is the case, we'll ensure that temporary diversions are in place to keep residents, contractors and visitors safe. We'll keep the disruption to a minimum.

Woodland recovery

Despite the tragic loss of trees, we'll be seizing the opportunity to increase the biodiversity in areas hardest hit. Where we've removed dying ash trees, we'll leave some areas to naturally regenerate, in others we'll replant with native broadleaves like beech, whitebeam, cherry and oak, while in others you'll see us adopt a mixture of both types of woodland management.

Our long-term aim is to improve the resilience of the woodlands against threats such as climate change and disease. By increasing species diversity alongside improving the natural age structure of the woodlands we can help their long-term survival.