Tree Health Survey


Join in - the best time to complete this survey is between May and September.

Help scientists monitor and protect our trees and woodlands

Mike Dilger and chestnut treeTrees 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.

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.

Enter your results online

Once you've completed the survey, simply submit your results:

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.

Problems entering your results online?

Send your results to:

OPAL, Centre for Environmental Policy,
Imperial College, South Kensington,
London SW7 2AZ.

Downloads - what you need to get involved

Survey pack

Also available:

Looking for the Welsh language survey pack?

Group leaders and schools

Download our group leader support guide, example risk assessment, and our new recording sheets for schools.

Recording sheets:

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

Watch it

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.

Watch it

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

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Tree ID guides at your fingertips:

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: