Ganoderma Butt Rot: Deadly Tree Disease

Ganoderma is a large genus of fungi which has been popularly associated with Asian medicine. And while some claim that Ganoderma fungi can improve human immunity and even cure cancer, Ganoderma can kill a tree.

Ganoderma Rot Disease

Ganoderma is a spore-born wood-rotting fungi that infects tree roots and root flares. Oaks, maples, ashes, elms, and other deciduous trees, as well as conifers and Palm trees are susceptible to infection. The fungus will not die until it has consumed the entire tree.

However, long before a tree dies from Ganoderma rot, the buttress roots and butt (lower trunk) of the tree are slowly damaged by decay. This can cause the tree to become a risk to property and people. The most pressing concern with the disease is tree stability.

Symptoms of Ganoderma Rot Infection

The most recognizable symptom of Ganoderma are the rusty red shelf mushrooms that form on the trunks of living or dead trees. These mushrooms, known as conks, are fruiting bodies which are responsible for the production of the fungi spreading spores. They are not the agent of attack. They are only the fruit of it, so to speak.

Other symptoms of Ganoderma rot include yellowing or wilting of leaves, die-back throughout the tree canopy, and reduced tree growth and vigor. However, it must be noted that generally healthy trees can tolerate a significant level of infection before showing symptoms. When symptoms do appear, a large portion of the root system tends to have already been infected. 

Disease Prevention

The most effective way to control Ganoderma rot is to prevent it. Proper planting, fertilization, watering and pruning practices are essential to fighting disease. Healthy trees are better equipped to maintain natural defenses against infection.

It is also important to guard your tree’s trunks or roots from contact with lawn mower blades, chainsaws, or other devices which might lead to wounds. Avoid mowing over a tree’s roots or using a weed whacker around the trunk. Ganoderma spores enter through wounds or openings on the tree’s surface.

Disease Management

While there is no cure to Ganoderma rot, there are several things that can be done to manage the disease. Trees with conks should be examined by a certified arborist immediately. Removing conks will do nothing to stop or slow the fungal infection.

Any tree that is infected, but is not a safety hazard, should be monitored closely. Efforts should be made to improve the tree’s health by following proper watering and fertilization practices and by removing any damaged or dead limbs.

Trees that have an advanced level of infection can be structurally unsafe and are a serious danger to property and life. Any tree with significant deterioration of the supporting buttress roots should be removed.

Live in Denton County, Texas? Contact Tree Shepherds. Our ISA Certified Arborists can help you with all of your tree care needs.