A very serious fungal disease, named after the yellowish-coloured toadstools that may appear around stumps or affected trees in autumn. From the dead wood, which the fungus lives on as a saprophyte, black threads spread into the soil and penetrate the roots of healthy trees and shrubs. If trees and shrubs start dying off one by one in a garden, honey fungus should be suspected. Peel off some bark from a dying plant. If there is a sheath of white, fungal growth underneath, possibly with some black root-like threads as well, the disease will be confirmed.
Remove dead and dying plants, and dig a trench about 45cm/18in deep around affected plants to isolate them. Change the soil before replanting it, preferably with honeyfungus- resistant species (such as bamboos, box, Cistus, Cotinus and Eleagnus spp., holly, honeysuckles, mahonias, Robinia spp., yews).