Tree Health Survey – join in today

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.

UK governments have already stepped up their activity to protect trees, and you can help too, by taking part in the OPAL Tree Health Survey, designed in collaboration with Forest Research and FERA.

Did you know?

Knopper galls, which can form on acorns, are caused by a tiny wasp called Andricus quercuscalicis. It first arrived in southern England in the 1950s and has now invaded most of the UK.

How to take part

Step 1 – Download and print the survey documents in English or in Welsh (ideally in colour).

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.

OPAL logoA good biosecurity routine can reduce the risk of spreading diseases and invasive species.

Watch this video to find out more about forest biosecurity measures

Ready to enter your results online?

Once you've completed the survey, simply submit your results using the online form.

You'll be able to see your contribution instantly on our interactive maps.

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.

Just submit a pest or disease sighting

Learn more about pests and diseases that can affect trees

Problems entering your results online?
Send your results to: FREEPOST RSCH-CHYJ-HYYC, OPAL, Centre for Environmental Policy, Imperial College, South Kensington, London SW7 2AZ.


Downloads – what you need to get involved

Ash leavesField guide:
Instructions and information about common UK tree species
  Tree health survey Field NotebookField notebook:
Recording sheets and information on pests and diseases to look out for
  Citrus Longhorn BeetleMost Unwanted
Guide: Pests and diseases that could pose a serious threat to trees

Tree ID guide and poster (PDF, 2.4MB) – a guide for your wall to help you identify common UK tree species


Electronic field record sheet for multiple trees (Excel, 52KB) – survey up to 50 trees on your laptop or tablet

Printable field record sheet for multiple trees, Activity 1 (Excel, 42.5KB) – record data by hand for up to 30 trees

Printable field record sheet for multiple trees, Activity 2 (Excel, 45KB) – record data by hand for up to 30 trees


Find out how the survey fits into the National Curriculum in England (PDF, 53KB)

Find out how the survey fits into the curriculum in Scotland (PDF, 126KB) and download an activity guide for teachers (PDF, 259KB)


You may download these documents for use in the context of the OPAL project only. All other rights are reserved.


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: