Prevent Hazard Trees on your Portland Property

tree hazards

Downed trees from a tornado.

Last week, after an epic wind storm hit the gorge, Interstate 84 in Oregon was shut down and 3 people were killed in Washington as a result of fallen trees. Most were caught by surprise, and it was a good reminder that it is always better to play it safe than sorry. During storms of any type, trees that are hollow, dead, or diseased create risk for people or property that may be nearby. Certified arborists are trained to identify potentially dangerous trees, also known as “Hazard Trees” to help prevent damage and/or death. Much of our work revolves around these Hazard Trees, and we can’t stress enough the importance of identification and maintenance for trees that may pose a problem.

It’s the Law – You Have to Take Care of Your Trees

Seriously. When damage, injury or death occurs because of a defective tree, the law usually holds the tree’s owner responsible. Under the law, it is your duty to exercise care, good judgment, caution, and foresight by inspecting your trees regularly and recognizing situations that may cause them to break or fall. If that freaks you out, let’s get down to the basics so you can breathe easy.

How to Perform a Hazard Tree Evaluation

in 3 easy steps…


Scrutinize the top and crown.

What type of tree is it? Some trees are just more brittle than others. Willows for example. Do your research to know what types of trees you have in your yard.

Are there dead limbs? Professionals call these widowmakers and know that this is no laughing matter. Dead branches require prompt action.

Do any branches cross or rub? Branches that cross or rub invariably lead to weak spots, and likewise should be pruned as soon as they are spotted.

What’s the history? Trees that have had limbs die in the past is often a sign of a bigger problem. Or, has this tree been “topped” before? That can lead to major issues which we explain in the previous post.

Is the tree dead or dying? Always call an expert if you think a tree could be dead. Dead or dying trees should be immediately removed, but not by you. It is a dangerous job to fell a large tree, leave that to the experts.

How vigorous is the tree? Look at the tree and determine the leaf cover, leaf color, size, and condition. Any problems found may be indicative of unseen problems or future problems. Unsure? Certified arborists are trained to make Hazard Tree evaluations and help you manage trees on your property, so give us a call to check it out.


Investigate the trunk.



Beware of forked trunks. Forked trunks where one side grows outward instead of upward pose a risk. Luckily, arborists can work with forked trees to strengthen them reducing risk.

Look for decay. Visible deformities like cankers and conks indicate decay. If nothing is visibly outward, arborists have special tools to identify decay before it is viewable on the outside of the tree.

Is the tree balanced? Leaning or lopsided trees present more of a problem than straight ones. However, if the tree has always grown like that, it is just something to keep an eye on. If a tree suddenly begins to lean, call an expert immediately.

Examine wounds and cracks. Wounds around the trunk of a tree are dangerous. Particularly those that go into the ground. If you see anything suspicious, ask an arborist to identify it for you. They’ll know if the wound increases hazard or not.


Consider the roots.

Many tree experts agree that over half of fallen trees are due to problems in the roots. Keep a keen eye for mushrooms growing near the roots and if you see any, call an arborist over to dig a sample. Homeowners often put tree roots at risk when digging trenches and holes, for whatever reason. This problem has two issues. Once a root is severed it can no longer hold the weight of the tree, weakening the overall structure. Severed roots are also open wounds which invite decay organisms  into the root system. Always call an arborist if you are planning any type of construction near a mature tree.

Arborists can help!

The bottom line is this, identifying the risk of a “Hazard Tree” is a tough job, and requires a nuanced, experienced eye. Trust a tree expert to give you thoughtful advice on how to deal with any Hazard Trees on your property, personal or commercial. ArborPro Tree Experts works in Portland and all the surrounding suburbs, so give us a ring.

Related posts