Honey Fungus
Honey fungus is a genus of parasitic fungi and lives in dead and decaying roots, tree stumps and other woody items in the soil. It grows out from these in the form of black root-like rhizomorphs ('bootlaces').
The rhizomorphs grow relatively close to the soil surface and invade new roots, or the root collar (where the roots meet the stem) of woody plants. An infected tree will die once the fungus has girdled it, or when extensive root death has occurred. As a forest pathogen, Armillaria can be very destructive. It is responsible for the "white rot" root disease.
Trees affected include:
The fungus also spreads from root to root where they are in close contact. The fruiting bodies of the fungus are mushrooms that grow on wood, typically in cestipose clusters. The honey fungus 'fruiting body' or toadstool appears in the autumn, if at all. Airborne infection by spores from the toadstools is rare.
Honey fungus can be prevented by removing tree stumps or other dead woody material such as roots from the soil, for example by mechanical stump-grinding. Killing stumps chemically is often not sufficient.
If the presence of honey fungus is confirmed, all dead or dying woody plants should be dug up and any roots or stumps removed. If removal of a stump is impossible, the stump can be ground, or chipped, by a contractor. The resulting woodchips should be burned or disposed of outside the garden, not used as a mulch. As a last resort, a stump can be treated chemically. NOTE: Without host plants the fungus will eventually die out. |