Ash dieback disease

Ash dieback is spreading throughout Hampshire and we will see the loss of most of our ash trees. This will have a significant impact on our landscape and wildlife. More importantly, dead and dying ash trees pose a risk to life and property and this risk must be addressed.

What is ash dieback?

Ash dieback is a disease caused by a fungus called Hymenoscyphus fraxinea, previous known as Chalara fraxinea, and is of eastern Asian origin. The disease causes leaf loss and crown dieback in affected trees and will in most cases lead to tree death particularly in younger trees. Evidence from continental Europe suggests that older, mature ash trees can survive infection for longer and continue to provide landscape and wildlife benefits for some time. However, over a period of 20 years we can expect a mortality rate of around 85% of all ash trees.

How to identify Ash dieback

Ash dieback was confirmed in Hampshire in 2014 and is spreading. Ash is a very common tree in Hampshire in woodlands and hedgerows and is important for wildlife and for wood products. To help you spot symptoms of the disease please visit the Forestry Commission's guide.

Report a suspected case of Ash dieback

All suspected cases should be reported directly to the Forestry Commission using the online reporting form on their website.

Advice for woodland managers and countryside workers

The Forestry Commission has published guidance called ‘Managing ash in woodlands in light of ash dieback’ for people who manage ash in woodlands in England, and there is guidance on biosecurity measures to help prevent spreading diseases. A Plant Health Order introduced in 2012 prohibits all imports of ash seeds, plants and trees, as well as all internal movement of ash seeds, plants and trees.

Advice for countryside visitors and householders

The risk of spreading the disease by visiting a forested area is low, but you can help by following the advice to forest visitors from the Forestry Commission. Householders with ash trees suspected of being infected should dispose of leaves by composting in situ or in their normal general rubbish bin and not in the green waste bins for composting.

Ash dieback on Hampshire County Council’s Farmed and Countryside Estate

The Countryside Service manages over 3000 hectares of countryside covering 80 Parks and Sites, the majority of which contain Ash trees.  The Service has been monitoring the spread of Ash dieback over the last few years on a site by site basis. These surveys indicate Ash dieback is widespread and there are ‘hot spots’ where action is being undertaken. The Countryside Service is working closely with partners such as the Forestry Commission to formulate appropriate plans and actions to respond to the spread of Ash Dieback as many of their sites have shared boundaries with other partners.

Ash dieback on Hampshire ‘s Highways

Hampshire Highways have been carrying out detailed surveys of ash trees along the highway network since 2018 and on average there is a ‘significant ash tree’ (> 20cm diameter) within falling distance of the carriageway every 326m. This is based on a survey of the primary routes (34% of network) and equates to approx. 25,400 trees across the whole network.  Of the trees surveyed in 2018 less than 5% displayed severe signs of dieback (>75%) but it is clear that the failure of ash trees along the highway and on adjacent properties is increasing.

The time for action is now!

Most trees adjacent to the public highway and within falling distance of roads and footpaths will be the responsibility of private landowners. All landowners and managers have a legal duty to maintain their trees and should ensure that any trees on their land are inspected appropriately and that action is taken to remove tree hazards. With Ash dieback now widespread, it’s particularly important that a landowner’s ash trees are inspected, and that action is taken to remove these where they constitute a hazard, especially alongside the public highway. We would also urge landowners to consider and carry out tree planting to replace any ash trees that are lost. Alternative species for planting are suggested in the Chalara manual - 2. Managing ash trees and woodland, including logs and firewood.

Ash dieback will continue to be monitored closely in accordance with established highway policy. Hampshire Highways is also committed to replacing any highway tree that is removed for highway safety and where space allows and will consider new sites suitable for tree planting where there is sufficient space above and below ground. 

Report a tree problem

Ash trees