Honey fungus
A destructive fungus that attacks and kills the roots of trees and shrubs, spreading underground by black, bootlace-like strands.
Also known as: Armillaria root rot, Shoestring root rot
Symptoms and identification
Plants decline, leaves are small and pale, and branches die back. Peeling bark at the base reveals a white, mushroom-scented fungal sheet. Honey-coloured toadstools may appear in fall.
Causes
The fungus lives on dead stumps and roots and spreads through soil by rhizomorphs. It is common in the UK and North America.
Organic treatment
Remove infected plants with as much root as possible. Replant with more resistant species such as yew, boxwood or bamboo.
Prevention
Remove old stumps and large roots, and keep plants healthy. A buried vertical barrier can stop the strands spreading.
Chemical treatment (use with care)
There is no effective chemical treatment for gardens.