Sweet chestnut blight: identification, reporting and control
Information about sweet chestnut blight (Cryphonectria parasitica), including how to report sightings.
Latest news
You can read the press notice Sweet chestnut blight outbreak prompts swift action and discover more in Forest Research’s blog New research investigates potential biocontrol programme to manage sweet chestnut blight.
Visit the Check a Sweet Chestnut campaign for more information on how to check for symptoms, this campaign is running from April to November 2026.
Sweet chestnut blight is a destructive disease of sweet chestnut trees (trees in the Castanea genus) caused by the fungus Cryphonectria parasitica.
It is regulated as a quarantine pest in Great Britain, meaning it is under official control measures and cannot be introduced, moved, multiplied or released without prior authorisation.
It is not native to the UK, although it is now widespread in Europe. Since 2011, the disease has been found at a small number of sites in England, which are subject to statutory control measures.
Symptoms
Sweet chestnut blight attacks the bark of sweet chestnut trees, entering through fissures or wounds. All symptoms on infected trees occur above ground.
The fungus can spread so rapidly through infected bark, causing stems or branches to become girdled – meaning the flow of nutrients is eventually cut off to the sections of the tree above the infection. This kills the tree above ground level, and the dead bark becomes visible as a sunken canker.
Orange fruiting bodies, which produce the spores that spread sweet chestnut blight are also visible on the bark. These erupt through lenticels (raised openings) and release long, orange-yellow tendrils of spores in moist weather.
Orange fruiting bodies and fissuring of the canker on sweet chestnut. Credit: Forest Research
When the canker girdles the stem leaves wilt and turn brown but remain hanging on the tree. Below the canker, branches retain healthy foliage and new shoots are produced after a short time. It is common to find many cankers on a single tree.
Young trees may die within a year of infection. Mature trees may take several years or more to decline and die.
The fungus can occasionally affect some species of oak when they are growing in very close proximity to heavily infected sweet chestnut trees, especially when they are significantly stressed. The disease does not affect horse chestnut (conker) trees.
More details and a symptoms guide is available on Forest Research’s sweet chestnut blight page.
Report sightings
Sweet chestnut blight has been found at a number of sites in the United Kingdom, principally in central and southern England.
Please remain vigilant for signs of sweet chestnut blight. If you think you have spotted signs of this disease anywhere in Great Britain, report it using TreeAlert.
Report suspected sightings in Northern Ireland using Treecheck, the all-Ireland tree pest reporting tool.
If you trade in plants in England or Wales and suspect sweet chestnut blight on your site, please contact your local Animal & Plant Health Agency (APHA) plant health and seeds inspector or contact planthealth.info@apha.gov.uk.
Management
Sweet chestnut blight is a notifiable plant disease. If you suspect it, you must be report it immediately to the relevant plant health authority – do not wait for confirmation before doing so.
You must not destroy or move any infected plants, bark or wood unless you have been instructed to do so by the Forestry Commission or APHA.
Demarcated area restrictions apply to parts of England where specific controls are in place to prevent spread.
Regulation
Cryphonectria parasitica is a regulated pest in the UK. Import restrictions apply to sweet chestnut material from all third countries outside the UK, including plants for planting, wood and bark. These restrictions are intended to minimise the risk of further introductions of the disease.
UK legislation also requires the use of UK plant passports for the movement of all Castanea species, including sweet chestnut, with bark and isolated bark of these species.
Plant health notice (sweet chestnut blight)
To protect England against sweet chestnut blight, the Forestry Commission has introduced a demarcated area around the Devon outbreak site under powers conferred by The Official Controls (Plant Health and Genetically Modified Organisms) (England) Regulations 2019.
Demarcated Area No.1 Notice comes into force 2 April 2026 and applies to the parts of Devon within the boundaries shown and described in the notice.
The notice:
- restricts the felling or killing of any trees of the genus Castanea without prior notification to the Forestry Commission
- restricts the movement of materials capable of spreading the disease both within and out of the demarcated area, including wood, chips and isolated bark
Provision is made within the notice to enable plant health inspectors to authorise movements and processing of material from the demarcated area where this can be achieved without risking the spread of sweet chestnut blight.
Landowners must provide notice of their intention to fell relevant material at least 30 days in advance of any felling in the demarcated areas. Felling may only commence once written authorisation is provided the Forestry Commission.
Contact
For all enquiries please contact sweetchestnutblight.authorisation@forestrycommission.gov.uk
Updates to this page
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Corrected date of notice. Demarcated Area No.1 Notice comes into force 2 April 2026 and applies to the parts of Devon within the boundaries shown and described in the notice.
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First published.