This article written by Susan Sanders, urban forestry commissioner and tree steward for the Carter Park Neighborhood, City of Vancouver, WA.
I have a huge, old ponderosa pine in my front garden in Vancouver, Washington. With all the news reports about trees falling during storms, I have worried if my tree is at risk of being next. And many of my neighbors have large, native Douglas firs or cedars in their yards.
Here in the Pacific Northwest we have ideal conditions for growing trees. Our native trees grow big here—that is what they do. It is frightening sometimes to hear news reports of downed trees during our winter storms. You may start to ask yourself questions like: Should I concerned about the stability of my trees? Could mine be next? Am I in danger?
I began doing some research and discovered there are usually clear warning signs that a tree is potentially unstable. A tree doesn’t just fall over. There is almost always an underlying condition that led to the tree’s failure, though this isn’t always reported on by the media. Being a careful observer and noticing changed in your trees, especially over time, helps to reduce risks or problems.
Arborists say these are indicators of problems in trees:
- A crack or split in the trunk of the tree
- The soil heaving or raising at the base of the tree
- Movement of the ground at the bottom of the tree, around the root plate, when it is windy
- Large, dead tree limbs
- Large cavities or hollows in the trunk along with other tree decay
- Large portion of bark that is peeling or falling away from the trunk
- Fungal/mushroom growth at or near the base of the tree.
Another thing that can put your mature tree at risk is recent construction near the tree. Potential damage caused by construction can include soil compaction, severed roots, physical injury to the trunk or crown, smothering of roots from added fill soil and changes to grade or drainage.
Whether construction or natural causes have damaged your tree, it would be a good idea to get a professional assessment about the health and stability of your tree by an International Society of Arboriculture (ISA) Certified Arborist. When choosing an arborist, ask if he or she also possesses the ISA’s Tree Risk Assessment Qualification (TRAQ). These professionals are trained to balance benefits with liabilities and can help you decide what is best for your tree.
I know my tree has many benefits to the neighborhood, especially since it is mature. It may be obvious but a large tree provides more long-term benefits than a small one. It cleans the air, assists with storm water runoff, cools the air, provides a habitat for birds, and helps us relax and feel better. It can also increase the value of my property! In the summer, sitting under that tree is a perfect place to cool down and its canopy will even provide some protection from a downpour in a rain storm.
Of course, trees can have risks but we all take many, many risks every day. I take risks every time I jump in my car and head to the grocery store, but that’s why I take my car to the mechanic regularly to be serviced. The same thing goes for the big beautiful ponderosa pine in my yard. Look for the warning signs yourself and hire a professional to help you minimize the risks of your tree. Perhaps there is wisdom in focusing on the beauty and benefits of large trees, rather than just the risks.
This article was republished with minor editorial changes from how it originally appeared in the May 2016 edition of the city of Vancouver’s Carter Park Neighborhood Association newsletter