Testing a range of ash species for tolerance to Chalara

This project aims to identify all the different ash species growing in arboreta in Britain, collect shoots for grafting onto native ash rootstock and then plant out onto sites where Chalara is known to be present. Trees will be monitored for infection rates and survival across the various species.

Research objectives

  • Source as many different ash species as possible growing in arboreta and botanic gardens in Britain
  • Identify at least 4 unrelated individuals within each species
  • Collect scions from selected trees and graft onto rootstock of native ash
  • Plant out successfully grafted trees in statistically replicated trials on three sites known to be infected with Chalara
  • Observe and monitor disease development and species survival
  • Consider possibility of introducing Chalara resistance into native ash by hybridising with species that demonstrating high levels of tolerance.

Results so far

  • Engagement with all the major British arboreta and botanic gardens: Westonbirt (Forestry Commission); Kew and Royal Botanic Gardens Edinburgh
  • Four individuals from a total of 29 species identified for scion shoot collection
  • Approx. 1/3rd of grafting completed spring 2014 (apical side veneer grafting)
  • Balance of grafting completed late summer 2014 (bud grafting)
  • Trees now all growing-on at Forestry Research nursery


Programme started in April 2014; end date 31st March 2017


Steve Lee

Funders and partners

  • This contract is being co-ordinated by Richard Buggs of Queen Mary University of London
  • THAPBI is funded under the auspices of the Living With Environmental Change Partnership with support from the Biotechnology and Biological Sciences Research Council, Department for Environment, Food and Rural Affairs, Economic and Social Research Council, Forestry Commission, Natural Environment Research Council and the Scottish Government
  • Main funder (80%) is BBSRC as part of the LWEC framework
  • Forestry Commission funds the balance (20%)

Forestry Commission policy

This project is seen as a major contribution to the objectives of the joint Defra-Forestry Commission ‘ Tree Health and Plant Biosecurity Action Plan’.