The best time to do this survey is between May and September.
Help scientists monitor and protect our trees and woodlands
Trees are vital – bringing nature into urban areas, supporting the rural economy, providing food and habitats for wildlife, and helping to combat climate change.
However, our trees are under threat. The number of pests and diseases attacking them has increased in the last few years.
How to take part
Did you know?
Knopper galls, which can form on acorns, are caused by a tiny wasp called Andricus quercuscalicis. It arrived in England in the 1950s and has now invaded most of the UK.
Step 2 – Find a site with safe access to one or more broadleaved trees and start surveying!
Step 3 – Tell us what you find using our simple online form.
Ready to enter your results online?
Once you've completed the survey, simply submit your results
using the online form.
A good biosecurity routine can reduce the risk of spreading diseases and invasive species.
Just want to submit a pest or disease sighting?
Use the form below to report a pest or disease without entering full survey data. Please include a photo if you can.
Get our free app
Tree ID guides at your fingertips with the OPAL Tree Health Survey app.
Problems entering your results online?
Send your results to:
OPAL, Centre for Environmental Policy,
Imperial College, South Kensington,
London SW7 2AZ.
Survey instructions and information about the most common UK tree species.
Recording sheets and information on the pests and diseases to look out for.
|Most Unwanted Guide (PDF, 1.18MB):
Pests and diseases that could pose a serious threat to UK trees.
Tree ID guide and poster (PDF, 2.4MB) – a guide for your wall to help you identify common UK tree species
- Electronic record sheet for up to 50 trees (Excel, 52KB) - for laptops/tablets
- Printable record sheet for up to 30 trees, Activity 1 (Excel, 42.5KB) – record by hand
- Printable record sheet for up to 30 trees, Activity 2 (Excel, 45KB) – record by hand
You may download these documents for use in the context of the OPAL project only. All other rights are reserved.
Looking for the Welsh language survey pack? Visit the Welsh Tree Survey page.
Policy and regulation
To find out about the action being taken by UK governments and their agencies to protect our trees from pests and diseases, visit:
- Gov.uk – sustaining and enhancing trees, forests and woodland
- Welsh Government – forestry
- Scottish Government – Forestry
- Northern Ireland Environment Agency – Forestry