Honey Fungus
Honey fungus is one of the most destructive pathogens a gardener can face, capable of killing a wide range of trees, shrubs, and woody perennials. In autumn it fruits in dense clusters of honey-coloured to tan mushrooms at the base of an infected plant or over its roots — caps often finely scaly, with a ring on the stem and pale gills. Its more telling signs are hidden: flat, white, fan-shaped sheets of mycelium beneath the bark at the base of the trunk with a mushroom-like smell, and tough black 'bootlace' rhizomorphs in the soil that spread the infection from plant to plant.
Ecologically it is also a powerful decomposer of dead wood and stumps, but in a planted garden its parasitic side dominates: infected plants show dieback, sparse or yellowing foliage, and sudden death, often after years of slow decline. Its autumn clusters can be confused with the deadly galerina, which fruits on wood in similar tufts — a serious reason never to trust clustered wood-growing brown mushrooms by eye.
Progressive dieback, sparse or yellowing foliage, poor growth, and eventual death of trees, shrubs, and woody perennials; white fan-shaped mycelial sheets under the bark at the stem base and black bootlace rhizomorphs in the soil; honey-coloured mushroom clusters in autumn.
Spreads through soil by rhizomorphs and via root contact with infected stumps and roots; favoured by stressed plants and by old stumps and buried wood left in the ground.
There is no chemical cure. Dig out and destroy infected stumps, roots, and as much of the rhizomorph network as possible, and grub out dead plants promptly. Replant the area with more resistant species and remove buried woody debris. Physical root barriers can slow spread between beds; keeping plants unstressed and well-watered improves their resistance.
Decomposes dead wood, stumps, and roots in woodland. The same aggressive wood-digesting ability makes it a serious garden pathogen when it reaches living plants.
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