Key Signs that a Tree May Be a Hazard

When do you know a tree is a hazard? A tree with a structural defect is considered as a hazard because this defect may cause the whole tree or its parts to fall on somebody or something of value. This is why it’s important to check your trees regularly.

A defective tree is considered a hazard only when the target (i.e., vehicles, structure, and people) is within the tree’s falling distance. So, if a tree is in the open area or away from the paths, then it is not considered as a hazard.


Whose Responsibility is it?

In case of injury, damage or death occurring due to a defective tree, the law states that tree’s owner is responsible. In the case of parks, the manager of trees is held responsible. The law says that it is the duty of tree owner to take care, properly judge, take caution, and act accordingly by regularly inspecting the trees and identifying the conditions that may cause them to break and fall.

How to Inspect a Tree?

When you’re looking for hazardous conditions in a tree, systematically inspect each tree. You should start from the crown (if necessary, use binoculars). After analyzing the crown, move to the trunk, and finally, inspect the root area. Here are some key signs that will help you in knowing whether a tree is hazardous or not.

1. Start from Top and Crown

While examining the top, consider the following points:

Type of Species: There are some species that are hard enough but actually breaks easily. This is one of the main reasons to discourage growing trees like box elders, silver maples, and willows. If these trees are already present in your property, then avoid locating patios or playing areas beneath them.

Look for any dead branches: Dead branches indicate that an accident can happen anytime. Even a light breeze, a mower’s bump, or a child climbing on those dead branches can make them fall. They’re a signal to take immediate action.

Look if any branches rub or cross: Branches that rub or cross each other create weak spots. Get rid of them at an early stage.

See if the tree is dying or dead: If a dead tree is in a human traffic area, it should be immediately removed. Consider an expert to remove it because it’s not easy to do it individually.

2. Check the Trunk

After inspecting the different aspects of the crown, move to the trunk portion.

Watch the Forked Trunks: If the tree has forked trunks, it’s the signal of weakness. If instead of growing upward, the fork grows outward, then it’s considered more dangerous. You should either prune them early or use braces or cables to strengthen the fork.

Check for signs of Decay: If there are cavities, disfiguration or live fungi present on the trunk or large branches, the tree is internally decaying. Sometimes, there are no visible signs. In such cases, you can use some tools like Mallet, Increment Borer, Drill and bait, and Shigometer.

Check the balance: In comparison to trees growing vertically, lopsided, or leaning trees are more of a hazard, but if the tree is slanted from the beginning, it is not that big of a risk. Sudden lean indicates that the support roots are weakened, and immediate action is required.

Look for Wounds and Cracks: If there’s any wound on the trunk, the tree can decay. If the wounds are extended to the ground, even lightning scars, the tree should be examined regularly. Some cracks, like frost cracks, shouldn’t be something to worry about, but if two vertical cracks are present on the opposite sides of the tree, this is a sign of breakage or root injury.

3. Don’t Ignore The Roots

The prime causes of a tree becoming a hazard are the condition of its roots. So, it becomes important to examine them as well.

Check the signs of Root Decay: It is very difficult to detect root decay because the roots are under the soil. If you want to detect root decay, look for the presence of mushrooms on or around the base of the tree. If mushrooms are present, or you suspect some root problem, call an arborist to dig some roots for clarity.

Look for severed roots: Severed roots cannot support the trunk and crown of a tree properly and, these roots are the open wounds that give the invitation to organisms that contribute to the decay.


These are some key signs that you should watch out for in a tree to determine whether it is a hazard or not. If you identify a tree as a hazard, don’t delay in taking the preventive measures. If you don’t feel confident doing the job yourself, remember that there are many experts who can help you out when it comes to tree trimming or removal.


Daniel Stone

Daniel has worked in the management, cutting, and caring for trees for the last 20 years. He works and helps run Bellarine Trees and is passionate about the environment and tree worker safety. He has a wife and two daughters and he enjoys playing tennis in his spare time.