It’s thought that the UK will lose around 80% of its ash trees. This will have a devastating impact on the landscape and biodiversity of our woodlands and natural habitats.
What does it look like?
The main signs of ash dieback are:
- dead branches
- blackening of leaves, which often hang limply on the tree
- discoloured stems, often with a diamond-shaped lesion where a leaf was attached
- trees may eventually drop limbs, collapse, or fall
The symptoms are often easier to spot in mid-late summer when a healthy ash should be in full leaf. It becomes much harder in autumn when leaves are naturally changing colour and falling.
Once a tree is infected the disease is usually fatal - but occasionally trees show some resistant to the disease.
Weakened trees are often killed by secondary pathogens such as Honey Fungus.
Blackening of leaves hanging limply on the tree
Diamond-shaped lesion on the tree
Recognise the symptoms of ash dieback in winter
Watch this video by the Forestry Commission
Recognise the symptoms of ash dieback in summer
Watch this video by the Forestry Commission
What are we doing?
Ash dieback on Hampshire County Council’s rural and countryside estate and properties
The Culture, Communities and Business Services department manages over 3,000 hectares of countryside and over 3,000 miles of public rights of way. Infected ash trees have been found:
- across the majority of our countryside and public rights of way
- across our rural estate
- on properties such as schools
The department has been monitoring the spread of ash dieback on a site-by-site basis. Routine tree inspections show ash dieback is widespread with ‘hot spots’ where action is being undertaken. We are working with partners to make plans and take action to respond to the spread of ash dieback.
Ash dieback on Hampshire‘s highways
Hampshire Highways has been carrying out detailed surveys of ash trees along the highway network since 2018. On average there is a ‘significant ash tree’ within falling distance of the carriageway every 326 metres of Hampshire’s primary highway routes. A significant ash tree is an ash tree with a trunk diameter of more than 20 centimetres. Less than 5% of these surveyed trees have displayed severe signs of ash dieback. These trees have been removed as quickly as possible.
Hampshire Highways track ash dieback along the highway as it continues to spread. The number of diseased ash trees that need to be removed alongside the highway is expected to increase.
Hampshire Highways is committed to replacing any tree removed due to highway safety. They will support appropriate replanting where there is enough space above and below ground.
Our ash dieback action plan
The County Council is currently producing an action plan to help reduce the impact of ash dieback on the county’s nature reserves. The first stage will be to identify any affected ash trees where there could be a risk of branches or entire trees falling.
We manage these trees to minimise any risk to people or property, by:
- felling (cutting down trees)
- crown reducing trees (remove certain parts of the tree)
- excluding people from areas where we are looking to keep ash trees a part of our work to promote ash dieback resistant trees
We are addressing the wider impact of ash dieback on wildlife. We will do this through a mixture of:
- replanting appropriate trees
- allowing natural regeneration to take place
Help prevent the spread of ash dieback
Countryside visitors and householders
Make sure you follow local advice and signs.
Do not proactively remove healthy ash trees due to ash dieback concerns. Ash trees are a vital habitat for birds and insects and some ash trees may have a natural resistance. Seeds from surviving ash trees can be used for replanting schemes.
If you think a tree might be infected by ash dieback, consult the ash dieback symptom guides on the Forest Research website. Double check the tree is an ash tree and not a rowan tree (also known as a mountain ash). Rowan trees are easily mistaken for ash and are not susceptible to ash dieback.
If you think a tree is infected with ash dieback, report it to the Forestry Commission online using their Tree Alert website.
You are not required to take any particular action if you own infected ash trees, unless the Forestry Commission asks you to.
Diseased mature ash trees do not need to be removed unless they pose a significant safety risk, as they are valuable to wildlife, take longer to die and can help us learn more about genetic strains that might be resistant to the disease.
Keep an eye on the trees' safety as the disease progresses, and prune or fell them if they or their branches threaten to cause injury or damage.
Householder’s gardens with ash trees suspected of being infected should dispose of leaves by composting in situ or in their normal general rubbish bin. They must not be put in the green waste bins for composting.
Why not look for opportunities to get involved in volunteer tree planting projects!
Landowners and woodland managers
If you own or manage woodland or trees you can follow the advice given by the Forestry Commission - managing ash in woodlands in light of ash dieback.
Most trees next 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. With ash dieback now widespread, it’s particularly important a landowner inspects their ash trees. They should take action to remove these where they are 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 Forest Research's Chalara manual - Managing ash trees and woodland, including logs and firewood.