How to prep and protect trees ahead of extreme winter weather

Last January’s ice storm led to widespread damage across the Willamette Valley, particularly from hundreds of trees falling due to wind and ice.

Now, experts say residents should prepare their trees ahead of this winter, possibly saving the trees, personal property and potentially lives.

Portland City Forester Jenn Cairo said the biggest risk isn’t entire trees collapsing, but large branches breaking off. Thick sheets of ice are typically the culprit.

“When we have extreme weather that’s unusual, that can add additional weight that the tree limbs aren’t accustomed to, and can lead to them cracking or breaking off,” Cairo said.

Trees crashed through multiple homes during the ice storm, including one in Lake Oswego that killed a man. Another tree crashed through an RV in Southeast Portland, which ignited a fire and killed one person inside.

And in Northeast Portland, three people were electrocuted when a falling tree branch brought a power line down on top of a vehicle.

Now, weather experts are forecasting another active winter season, with a La Niña system that typically leads to cooler temperatures and more precipitation.

Related: Oregon could see wetter and cooler winter conditions this year, thanks to La Niña

During extreme weather, there are some signs that a tree could be at risk for falling down, Cairo said. Trees leaning in a more pronounced direction, foliage that is unusually discolored and increased insect activity are all potential symptoms of something being wrong.

She also said people caring for their trees can unintentionally put them at risk. If all the lower limbs of a tree are removed, for example, that causes the top of the tree to act like a sail, making it easier to blow down.

The Oregon Department of Forestry also advises homeowners to be careful where they plant new trees, and first ensure they won’t pose any risks.

Cairo recommended that property owners hire experts to inspect their trees and perform maintenance before winter begins.

“I encourage people to think of it as a good investment, so that their trees can be healthy and stable,” she said.

Depending on the tree’s location and size, the city of Portland may require a permit for pruning or removal.

ODF: Oregon Homeowner’s Guide to Tree Care (pdf)