Ganoderma Tree Disease: Signs, Risks & When to Be Concerned
Ganoderma is one of the most common fungal diseases affecting trees throughout the UK and can pose a serious risk to tree stability if left unmanaged. Often found at the base of mature trees, Ganoderma causes internal decay which gradually weakens the structural integrity of both the trunk and root system.
While some infected trees can remain standing for years, others may become hazardous over time — particularly during periods of high winds or poor weather conditions.
At Tall Tree Services, we regularly assess trees affected by Ganoderma across Gloucestershire, helping homeowners identify potential risks and manage trees safely.
What Is Ganoderma?
Ganoderma is a type of fungal decay that attacks the lower stem and roots of trees. The fungus breaks down the wood internally, reducing the tree’s strength and stability over time.
Several species of Ganoderma exist in the UK, and the disease commonly affects:
Willow trees
Beech trees
Oak trees
Maple trees
Plane trees
Poplar trees
The fungus is typically identified by large bracket-like fruiting bodies growing around the base of the trunk or root flare.
Common Signs of Ganoderma
Some of the most common symptoms of Ganoderma include:
Bracket fungi growing at the base of the tree
Areas of decay around the trunk
Hollowing or weakened wood
Deadwood within the canopy
Reduced leaf coverage or canopy decline
Sudden branch failure
Signs of root instability
In many cases, the extent of internal decay can be far more significant than what is visible externally.
Why Ganoderma Can Become Dangerous
One of the biggest concerns with Ganoderma is the effect it has on a tree’s structural stability.
As decay progresses internally, the trunk and root system can become significantly weakened, increasing the risk of:
limb failure
stem failure
partial collapse
uprooting during storms or high winds
In some cases, trees may still appear relatively healthy externally while extensive decay is developing internally.
This is why professional inspection is important, particularly for trees located near:
homes
roads
footpaths
gardens
parking areas
public spaces
Does a Tree With Ganoderma Always Need Removing?
Not always.
The appropriate course of action depends on several factors, including:
the extent of decay
the species of tree
its location
surrounding targets
overall structural condition
Some trees can be monitored and managed through regular inspections and pruning, while others may require removal if the level of decay presents an unacceptable safety risk.
Every tree should be assessed individually by a qualified arborist.
Recent Ganoderma Tree Removal in Gloucestershire
We recently carried out the removal of a mature willow tree in Gloucestershire affected by advanced Ganoderma decay.
Due to the extent of internal deterioration, the tree had become structurally compromised and unsafe to retain. Our team safely dismantled the tree in sections to minimise risk to the surrounding area and property.
Cases like this highlight the importance of identifying decay issues early before they develop into larger safety concerns.
Professional Tree Inspections in Gloucestershire
If you’ve noticed fungal growth, deadwood, canopy decline or signs of decay in a tree on your property, it’s important to seek professional advice.
At Tall Tree Services, we provide professional tree inspections, tree surgery and safe tree removals across Gloucestershire.
Our experienced team can assess the condition of your trees and recommend the most appropriate management solution for both safety and long-term tree health.
Contact Tall Tree Services today for professional advice and a free quotation.