Identifying Tree Defects

pileated woodpecker family
Figure 1: Pileated woodpecker family. Image credit: Steve Byland

Dead or dying trees in the middle of your woodland can be the perfect habitat for a myriad of species like a family of pileated woodpeckers (figure 1) or the porcupine (figure 2). Yet, a dead or dying tree can become a hazard if it is located too close to a house, driveway, or along a trail frequented by you or your family.

Contact a tree care professional if you see the following defects* on a tree either close to your home or along a trail on your property:  

A. Cracks and weak branch attachments

Cracks are splits along the bark and can extend into the wood and through the tree.  Take immediate action if any cracks are found during inspection. A weak branch attachment may occur at a branch union angle less than 45 degrees, but not always. If the union of the two branches is very tight, then bark may grow in between the branches. The 'included bark' is not as strong as wood and may eventually force the two branches apart. 

B. Decay

Signs of decay do not necessarily mean the tree is hazardous. Trees have the ability to compartmentalize injuries or close off decaying tissue by surrounding it with healthy tissue. Upon inspection, make note of how much decayed wood exists compared to sound wood. Mushrooms are a sign of advanced decay. Call a tree care professional to evaluate any tree cavities, especially those associate with mushrooms or found at the base of the tree.

porcupine tree
Figure 2: Trees with cavities near the ground offer habitat for animals like this porcupine. Image credit: Bob Shank

C. Dead wood

Remove any dead wood immediately. Predicting when a dead branch will fall is not possible considering it can happen during a wind storm or on a perfectly calm day - usually without a sound.


D. Hanging branches

A hanging branch is a broken branch that is either still slightly attached or has broken off completely getting stuck in the canopy on the way down. Branches that have already broken off are typically called 'widow makers' and are extremely dangerous.





*This page is not inclusive of all the defects that can be found on trees. If you're concerned about a tree on your property, contact a tree care professional.

tree defects ppt pics

tree sketch with defects
Illustration showing a tree with multiple defects