Look for
Leaves will become a dark brown colour and drop. Blossoms will die back. Fruits will become discoloured and wrinkled. A white slimy substance may excrete from infected areas. Often, the first time this disease becomes apparent is when new leaves do not appear in spring on deciduous trees and shrubs. Alternatively, woody plants may suddenly defoliate and die-back along their stems. Determining the cause as honey fungus can be tricky though. A clear indicator is the presence of strands of the fungus in the soil around affected plants. These look like thick black bootlaces. Pale brown or yellowish toadstools may appear in autumn and a gooey resin may be found oozing from the base of stems.
Plants affected
- The most susceptible include: apples, crab apples, walnut, willow, wisteria, cotoneaster, rhododendron, roses and many conifers, including pine, cypress and thuja. In addition almost all garden trees and shrubs and some herbaceous plants can also succumb.
About Honey fungus
- Honey fungus lives in dead tree stumps and spreads from there to healthy plants nearby.
- There are a group of closely related fungi which are collectively known as honey fungus.
- Honey fungus is notoriously difficult to diagnose as the symptoms are easily confused with other problems.
- Honey fungus remains in the soil for years if allowed to establish.
Treatment
Chemical
There is currently no chemical control commercially available for honey fungus.
- Remove diseased plants and dig out the roots as far as possible.
- Do not replant with trees or shrubs for at least a year.
- Remove and replace the infected soil from around the affected plant.
- Where possible, have any large stumps removed from the garden.
- When replanting, stick to resistant plants such as oak, ash, beech, yew, clematis, laurel or mahonia.
- Sterilise any tools used for removing infected material with a household bleach solution after every use
- Remove diseased plants and dig out the roots as far as possible.
- Do not replant with trees or shrubs for at least a year.
- Remove and replace the infected soil from around the affected plant.
- Where possible, have any large stumps removed from the garden.
- When replanting, stick to resistant plants such as oak, ash, beech, yew, clematis, laurel or mahonia.