Our stormy weekend hasn’t been kind to trees. The one in Benjamin Hutchinson‘s photo, above, toppled onto an Alki sidewalk overnight. Our Saturday coverage showed several cases of sizable trees or branches falling in the wind – bringing down wires in The Junction, mashing a car on 40th SW in Morgan Junction. Trees are a big part of what makes our city so beautiful – Seattle has seven times as many trees as people! – but you might wonder sometimes which one(s) are at risk in the next 45+-mph gust. We took the tree-safety question to arborist Mark Harman from longtime WSB sponsor Stonehedge Tree Experts, who is also a certified tree-risk assessor. Here’s his reply:

With these strong winds recently and the accompanying damage that may result from trees or their parts flying off or falling on your car or home, it makes one take a second look at the large trees around us. Should we be worried about the trees in our yards or the neighbors’ yard? Here is my opinion from a guy who has been working with trees for the last 30 years from Washington to Idaho.

Around here in the Seattle area, it is very unusual for a healthy tree to totally blow over. Of those trees that do blow over or those trees that lose the top part of the tree, almost all of those episodes could have been predicted if an experienced Arborist had looked closely at the tree prior to it falling apart. There are almost always signs on the tree that show its problems. Trees have “body language” – they can tell us if they are sick, hollow, rotten, twisting, failing, or tipping over. We just have to be educated to read those signs.

Every tree species has its own problems:

Hemlocks are very prone to root rot, making them vulnerable to tipping over or breaking at the stump. (Like the one on 40th SW between Morgan and Fauntleroy.) Douglas Firs shed limbs. Corkscrew willows break limbs and stems during snow loads. Black Cottonwood shed large limbs. Native Big Leaf Maples break apart when they have multiple stems weakly attached. Some trees never ever break. The London Plane Trees have the strongest branches of all, never breaking. Beech trees are another very strong tree. Alders die back from the top down, but their base and roots will be sound.

It’s interesting to note that after windstorms, I rarely ever get calls from my clients. That’s because I have been keeping an eye on their trees for many years, watching for signs of problems and then dealing with them before the worst happens. When I watch the TV news after storms and see the film clips of trees on houses, I bet big bucks that those trees were either diseased, dead, full of ivy, or had their roots cut during recent construction of the new house or garage next door. It could have been predicted if a qualified Arborist had been watching over those trees.

Granted, there are always exceptions, and if we all get paranoid and decide we can’t live with some risk from the trees around us and cut them all down, this is going to be a pretty boring place to live.

So the wise thing to do if you want to know how risky those trees are around you would be to hire or consult with a Qualified Arborist. Preferably a Certified Arborist with membership in the International Society of Arboriculture. Some of us are trained as “Tree Risk Assessors” who understand the body language of the trees. We can do a risk analysis of your trees, finding and dealing with problems before they occur.

Mark Harman
Certified Arborist and Certified Tree Risk Assessor
Stonehedge Tree Experts, Inc.

Not sure what kind of trees yours are? Here’s a city info-sheet that might help.