Honey Fungus is a name used to describe various fungi which decay trees by affecting the root system and then subsequently spreading decaying parts of the tree above the ground.

Usually it is initiated by a tree wound or a tree weakened by unsuitable environmental factors. 

Rhizomorphs spread under the ground from the affected tree further infecting other healthy trees and shrubs that they reach. 
These rhizomorphs remain invisible underground and spread up the tree under the bark.

The ability to reproduce itself this way means honey fungus doesn't necessarily depend on finding damaged wood to infect as other fungi do. 

A root examination can assist in early diagnosis. 



Visible Signs

Parts of the upper tree may die as damage to the root system prohibits enough nutrients reaching these parts. 

A yellow coloured Fungi may appear at the base of the tree trunk and the bark may bleed and crack in this area. 

If the bark comes away from the tree, rhizomorphs with a bootlace appearence may be seen.

The tree may not flower as expected. Either not flowering at all, or overly heavy flowering.

 Leaves may be weak in colour and small in size.

A white fungus may develop at the base of the tree under the bark leading to the bark falling away.