Trees are valuable assets, but when they become unstable, they pose serious risks to people, buildings, and infrastructure. Many signs of a dangerous tree are not obvious to the untrained eye. Here are seven warning signs that a tree on your property may need urgent attention.
1. Significant Trunk Lean
While some trees naturally grow at an angle, a sudden or increasing lean is cause for concern. Look for exposed roots on the side opposite the lean, cracked soil around the base, and a lean that has changed noticeably over recent months. A tree that was once straight but now leans has likely suffered root failure.
2. Visible Trunk Decay and Cavities
Large cavities, soft or spongy wood, mushrooms or fungal brackets growing on the trunk, and sections of missing bark all indicate internal decay. A tree can appear healthy from the outside while being hollow inside. Fungal fruiting bodies, particularly shelf-like brackets, indicate decay fungi are actively breaking down the wood.
3. Dead Branches in the Crown
Dead branches, especially large ones, are unpredictable. They can fall in calm weather without warning, which is why they are known as widow-makers. If you notice large, leafless branches within an otherwise green canopy, this could indicate localised dieback from disease, root damage, or structural problems. Prompt assessment by a dead tree removal specialist is recommended.
4. Cracks in the Trunk or Major Branches
Deep vertical cracks, splits at branch unions, or horizontal fractures in the trunk are serious structural defects. These indicate that the wood is under stress and may fail under load from wind, rain, or the weight of the canopy itself. Co-dominant stems with included bark — where two main trunks grow tightly together with bark trapped between them — are a particularly common failure point.
5. Root Problems
Roots anchor and stabilise the tree, so any root damage is a serious concern. Signs of root problems include:
- Visible root decay or mushroom growth at the base of the tree.
- Recent construction, trenching, or soil compaction within the root zone.
- Heaving or cracking soil on one side of the tree.
- Roots that have been severed for driveways, paths, or utility work.
If roots are damaged, the tree may need professional removal before it fails unpredictably.
6. Proximity to Structures and Power Lines
A tree does not need to be unhealthy to be dangerous. Large trees growing too close to homes, garages, power lines, or play areas represent a significant risk simply due to their location. Even a healthy branch can fail during a storm, and a tree that would be perfectly safe in an open paddock becomes a liability when it overhangs a bedroom.
7. History of Branch Failure
If a tree has dropped large branches before, it is likely to do so again. Repeat branch failure suggests systemic issues such as weak wood, internal decay, poor branch attachment, or root stress. Take previous failures seriously as a predictor of future risk.
What to Do If You Spot These Signs
If any of these signs are present, do not ignore them. A tree risk assessment by a qualified arborist can determine the severity of the hazard and recommend appropriate action. For more guidance on identifying tree health issues, read our guide on dead tree removal and when to act. In urgent situations, emergency tree removal services can respond quickly to make your property safe.
Do not wait for a dangerous tree to fail on its own terms. Find a qualified arborist in your area today and get a professional risk assessment before it is too late.