Report a tree pest or disease in the United Kingdom: TreeAlert, TreeCheck and the plant health offices
Who the United Kingdom agencies say takes a report of a suspected tree pest or disease, the online tools and phone lines they publish, what they ask a reporter to include, and the pests they name.
Checked against the sources at the bottom of this page on October 8, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. It sets out how Forest Research and the plant health offices describe reporting a suspected tree pest or disease in the United Kingdom, with the date each page shows where it shows one. For the wider country-by-country picture see tree pests and diseases.
Who takes the report
| Where the tree is | Route the agency gives | Source and date |
|---|---|---|
| England, Scotland and Wales | TreeAlert, the online reporting tool run by Forest Research. Its home page says it takes reports of suspected tree pests and diseases found anywhere in Great Britain. | Forest Research. No date shown on the pages. |
| Northern Ireland | TreeCheck, which Forest Research calls the all-Ireland tree disease reporting tool. | Forest Research oak processionary moth page. No date shown. |
| Plants outside woodland, or plants moving in trade, England and Wales | Animal and Plant Health Agency, telephone 0300 1000 313. | Forest Research ramorum disease page. No date shown. |
| Same, Scotland | Scottish Government plant health, telephone 0131 244 8923. | Forest Research ramorum disease page. No date shown. |
| Same, Northern Ireland | Department of Agriculture, Environment and Rural Affairs, telephone 0300 200 7847. | Forest Research ramorum disease page. No date shown. |
The same route appears on the GOV.UK biosecurity page, last updated January 20, 2026, which tells the public to report trees they suspect are in ill-health through TreeAlert, to the Forestry Commission, Scottish Forestry and Natural Resources Wales.
What the agency asks the reporter to include
On the Forest Research TreeAlert page, the agency lists what a report needs. The reporter gives a name, an email address and a level of experience. The report gives the date of the observation, the type of location, and the place of the problem as a grid reference, a point on a map or a postcode. Forest Research says it prefers the map or grid reference, and that a 10-figure grid reference is best, with 6 or 8 figures accepted. The report also gives the number of trees, their approximate age and trunk diameter, whether the tree is a conifer or broadleaf, its species, where on the tree the symptom sits, and the symptom itself. Forest Research asks ideally for three photographs: the tree in context, the symptom in context and the detail of the symptom.
For oak processionary moth, the Forest Research page says that reports sent by email or telephone instead of TreeAlert include a precise location, a daytime telephone number, a clear photograph if possible and the owner's contact details if known.
Pests the agency names
TreeAlert has its own report forms for chalara dieback of ash, Dothistroma needle blight, acute oak decline, Phytophthora lateralis, Asian or citrus longhorn beetle and oak processionary moth. Its general report form covers any other problem. The Forest Research oak processionary moth page says to report nests even when no caterpillars are seen, says not to touch spent nests, and says the plant health authorities do not require reports of adult moths. It also says that suspected sightings of ramorum disease on trees or other woodland plants must be reported to the forestry authorities. The Defra Plant Health Portal Xylella page, last updated December 17, 2025, describes Xylella fastidiosa as a bacterial disease not known to occur in the United Kingdom.
The biosecurity steps the same agencies list for tools, boots and vehicles are in the biosecurity table by pest. The guides on ash dieback and oak processionary moth give the rules for those two.
Sources
- Forest Research, TreeAlert home page, read October 8, 2026
- Forest Research, TreeAlert: what you need to make a report, read October 8, 2026
- Forest Research, oak processionary moth page, read October 8, 2026
- Forest Research, ramorum disease page, read October 8, 2026
- GOV.UK, how biosecurity can prevent the introduction and spread of tree pests and diseases, updated January 20, 2026, read October 8, 2026
- Defra, UK Plant Health Information Portal, Xylella fastidiosa, updated December 17, 2025, read October 8, 2026