Every year, our landscape changes as trees fall or break, causing property damage, power outages, and injury. While some tree failures are unpredictable, many can be prevented. By inspecting your trees for warning signs, many potential problems can be corrected before problems arise.

Trees should be inspected on a regular basis especially before and after storms. Larger trees have a greater hazard potential than smaller trees. A hazardous tree is a tree that has significant structural defects that are likely to lead to failure and possibly cause injury or damage.

If a tree is deemed hazardous, keep people, pets, and vehicles out of the area until the hazardous condition has been corrected.

Seek Professional help from one of our certified arborists to evaluate the potential hazards before the next storm hits. We can recommend the proper course of action to keep your trees safer and healthier. The following guidelines can help you recognize the warning signs of hazard trees.


Past tree care, construction and landscape activities can affect the health of your trees. Construction, trenches, and tree topping can all have adverse effects on your trees. If roots have been cut or disturbed, the tree may become unstable.

Trenching in the critical root zone can cut anchoring roots and increase blow down risk


Trees do not necessarily grow straight up. However, trees with a significant lean may indicate a problem. Look for cracked soil and exposed roots around the base of the tree which may indicate the tree has recently begun to lean.

Another warning sign is a tree that has begun to lean. Pay close attention to trees that have recently moved from a vertical position.

Multiple Trunks

Some trees develop multiple trunks. Trees with multiple trunks can break if the trunks are weakly attached. Trees with large trunks with splits or cracks have a high failure potential. Inspect these trees for cracks or splits where the trunks meet.

Multiple trunks are susceptible to splitting.

Weakly Attached Branches

Inspect branches where they attach to the trunk. Tight V-shaped forks are more prone to break than open U-shaped unions. Trees with splits, cracks, and/or several branches arising from the same point on the trunk may also present problems.

Cavities & Decay Pockets

Inspect the trunk or branches for peeling bark and hollow or decayed areas. Large decay pockets and decay where branches meet the trunk can indicate serious structural problems. Mushrooms or conks growing on or at the base of a tree are signs of decay-causing fungus.

This oak tree with a large trunk wound is one example of a decay pocket.

Trunk & Branch Cracks

Inspect the trunk and large branches for cracks. Deep, large cracks indicate structural weakness in the tree and need careful evaluation.


Hangers are broken branches still lodged in the tree. Whether partially attached or separated completely from the trunk, hangers are likely to fall unexpectedly and should be removed. Stubs left by broken branches should be removed to prevent spread of decay.

Hanging dead branches in this Douglas-fir are likely to fall and should be removed immediately.


Dead branches, or deadwood, will eventually fall. Branches over two inches in diameter can cause serious damage when they fall. Removal of deadwood may not be critical, but it should not be ignored.

Deadwood in this tree should be removed before failure occurs.