Ash dieback

Find out about ash dieback, how we manage its impact and information for tree owners.

Ash dieback disease is caused by the fungus Hymenoscyphus fraxineus, formerly known as Chalara fraxinea. In West Sussex, nearly 21 per cent of all broadleaved trees are ash, covering 4,968 hectares.

The disease has the potential to kill 95 per cent of West Sussex ash trees over the next 10–20 years. This would have a major impact on the county’s landscape, the wildlife it supports and other ecosystem services that trees provide such as:

  • filtering the air
  • storing carbon
  • reducing flooding
  • providing shade
  • protecting soils.

For more information, including how to recognise and report the disease, visit Forest Research.

How we manage its impact

A targeted drive-by survey of some of the county’s roads was carried out in summer 2019 to record where ash trees are. This information was analysed to help prioritise more detailed condition surveys and any action required, such as felling. The results of this analysis are in the reports below. The rest of the highway network was surveyed in summer 2021.

Our plan to manage ash dieback is closely aligned with the Ash Dieback Action Plan Toolkit. Working proactively with districts, boroughs, other neighbouring authorities and stakeholders will effectively tackle the impacts of ash dieback and promote long-term recovery and resilience in our treescape.

Information for tree owners

Tree owners have a legal duty of care and must maintain their trees in a reasonably safe condition. We are only responsible for trees growing on council property, including adopted highway verges.

In almost all cases, trees that are next to roads and public rights of way are the responsibility of the neighbouring landowner. Where a tree on private land poses a danger to the highway users, we may contact the landowner and explain what work needs to be done and when it should be completed by. The tree owner is responsible for the cost of this work.

For most landowners, the first step will be to contact a tree surgeon. They will be able to provide quotes for the work required and advice on what traffic management will be needed while the work is carried out. The Arboricultural Association has an approved contractor and consultant directory.

Check the standing advice for protected species before any work starts.

The Tree Council has produced guidance for homeowners and those with ash trees on their land. The guide helps tree owners to address any safety risks posed by ash dieback while helping to reduce the ecological impact of the disease.

Information for woodland owners

If you own woodland which contains ash you should be aware of the following:

  • It is recommended that you create or update a management plan to take account of the current or likely future impacts of ash dieback. Countryside Stewardship grants are available for new management plans on woodland areas over 3ha.
  • Markets for lower grade timber are available which may help reduce the cost of felling.
  • Grants are available under Countryside Stewardship which can contribute towards the cost of restocking and ongoing management. Parish councils are also eligible to apply for Countryside Stewardship.

Specific guidance on managing woodland containing ash is available in Forestry Commission Operations Note 46.

To find out about Forestry Commission grants, tree felling licences, regulations and managing private woods and forests, visit GOV.UK or contact your local area office.

Tree works, traffic management and road closures

If you need to close a road or install a temporary traffic regulation, such as a lower speed limit to manage traffic while work is being carried out on a tree, you will need to apply for a Temporary Traffic Regulation Order.

If you need to use other forms of traffic management, such as traffic lights, please apply to work on the highway.

Please note: For the purposes of felling diseased roadside ash trees only, there will not be a charge for the Temporary Traffic Regulation Order. To ensure you are not charged, please state clearly on your application form within the works description that the works are for felling ash trees infected with Ash Dieback.

Tree works and public rights of way

If works are required near to, or on public rights of way, please contact the Public Rights of Way team via the Report a Problem with a Right of Way page at the earliest possible stage to discuss your proposals. These paths are public highways as much as public roads and you have a duty to keep them open for safe and convenient use until such time as a formal closure is agreed with the County Council.

If path closures are required you will need to apply for a temporary closure. We will assess each application on its merits and expect applicants to minimise any closure period - it may be possible that paths can be kept open by adopting a different work practice. It would be helpful to supply a copy of your felling plan and timetable. We will need to be satisfied on the standard of reinstatement, which is required to be no lesser a standard than existed prior to works.

Please note: For the purpose of felling diseased ash trees alongside a public rights of way only, you will be eligible for a courtesy closure for up to five days free of charge. To be eligible, please clearly state on your application form within the works description that the works are for felling ash trees infected with Ash Dieback.

Tree Preservation Orders (TPOs), trees in conservation areas and felling licences

To check whether the tree requiring work is subject to a TPO, or in a conservation area, contact the tree officer at your relevant district or borough council before starting any work.

Under the Forestry Act 1967 as amended, a licence is required to fell most trees. Details of how to apply for a licence, and any exemptions which may apply, are outlined in the Tree felling - getting permission document, available on GOV.UK.

Further information

Last updated:
30 November 2023
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