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Check a Sweet Chestnut

13th Jul 2023

As part of National Plant Health Week in May, Check a Sweet Chestnut was launched. This is a collaboration between the RHS, Defra, APHA, Forest Research and Observatree looking to understand the health of sweet chestnut trees in the UK.

Running over summer Check a Sweet Chestnut invites you to find a local sweet chestnut tree and report its health to TreeAlert.

What is a sweet chestnut tree?

Sweet chestnuts are large trees with long glossy green leaves and are found throughout the UK in urban areas, parks and woodland.

Sweet chestnut
Photograph: © Forestry Commission/ISOBEL CAMERON

What am I looking for?

Look for Oriental chestnut gall wasp leaf galls

Oriental Chestnut Gall Wasp gall
TreeAlert 111967
Oriental Chestnut Gall Wasp gall
TreeAlert 112375
Oriental Chestnut Gall Wasp gall
TreeAlert 112376

and disfigured patches of bark with a sparse crown of leaves (symptoms of sweet chestnut blight)


Fruiting bodies of Cryphonectria parasitica on a chestnut blight canker.





















Chestnut blight canker on the stem of a sweet chestnut tree. Note ragged appearance of the cankered bark and presence of epicormic growth.






















Report your findings

In order to report a healthy tree you must register with TreeAlert and compile a ‘healthy trees’ report, or if you find Oriental chestnut gall wasp or sweet chestnut blight you can complete a ‘general report’ and select ‘2023 Check a Sweet Chestnut’ as the project (although you do not have to be registered to complete this). Selecting this project will enable us to distinguish these reports from other TreeAlert data and add to previous records collected between 2020 and 2022 for Project HOMED.

TreeAlert screenshots
TreeAlert screenshots

If you are registered your contact details will auto populate at the start of the reporting process speeding up the time it takes to submit a report.  You will also be able to view your healthy and general reports after submission.

In summary:

  • Get prepared
  • Find a sweet chestnut tree
  • Check the tree’s health
  • Report sightings via TreeAlert

Find out more! Check a sweet chestnut | RHS / RHS Gardening