Professor Adam Hart looks at the disease that has devastated ash trees in Europe – ash dieback. Over the last 20 years the fungus that causes ash dieback has been spreading westwards across the continent and last year it was found in the UK for the first time. At the moment there is no cure for the disease and only a tiny fraction of trees seem to be able to survive it. In this programme, he investigates the very latest scientific research into this deadly disease and asks if it will be enough to save this important species.

(Image: Professor Adam Hart in Trolleholm seed orchard in Sweden where ash dieback has infected many of the trees. Credit: BBC)