Forest Research looks for ash dieback resistant trees
Several strains of Ash tree are being planted at 20 different sites across East Anglia in a bid to find varieties resistant to the Ash Dieback fungus.
Forest Research, part of the Forestry Commission, is leading the project to plant 250,000 trees on land donated by farmers, charities or councils.
Most of the trees are in areas of known infection by the fungus Chalara fraxinea that causes ash dieback.
Britain's 80 million ash trees are under threat from the fungus.
In Denmark, a variety known as Tree 35, which makes up 2% of the species' population, has managed to survive the epidemic.
Forest Research now wants to see if there are other trees with natural resistance.
If resistant strains are found then they will be propagated to produce ash trees for the future, Forest Research said.
Grants have been made available from the Forestry Commission to help fund and support the removal and disposal of infected ash trees and replacement with alternative species.
The organisation also wants to make woodlands more resilient for the future by increasing the number of species.
Forests in Norfolk, Suffolk, Kent and Essex are among the worst affected, and the disease has now spread to woodland and nurseries across the UK, according to the Forestry Commission.
The first three cases of ash dieback in 2013 were found in Wales, the Forestry Commission confirmed.