Have you ever seen a dark orange to purple mushroom at the base of a tree trunk or out in the grass around a tree? It might be Ganoderma, a saprophytic fungus that almost always results in death of the tree.

How does it happen? The spores of these fungi enter a tree’s root system when the roots are severed and the woody tissue is exposed. Tree roots can be severed from mower blades or weed eaters, or during installation of utilities or new construction. Ganoderma already exists in the soil, it just needs an open wound to enter the tree and infect it. Once it is in the tree’s system, the tree could live for an indeterminate amount of time and not show any symptoms, or it could show branch dieback, leaf wilting and crown thinning. A sign that the tree has Ganoderma is when the fungal conk, or mushroom, grows at the tree trunk base or along the roots on top of the grass, letting you know the tree is infected.

Ganoderma is not a treatable fungus so tree removal is almost always recommended. Another option is to have a root excavation performed with an air spade by a Certified Arborist to see the extent of root dieback. This will tell the tree owner the extent of structural root damage and an approximate estimation of how soon removal needs to occur. Very early detection, caught early enough, could mitigate removal in some cases.