No, don’t even mention ice storms; my trees can’t take it!

ice-damaged tree
The weight of ice broke several large limbs from this tree in Olympia last January. Photo: DNR

Light rain, heavy rain, showers, scattered showers, rain at times, chance of showers… however you say it, the Washington State weather forecast calls for rain. And we all know that rain could turn into ice later this winter. It did last January.

With this in mind, did you know that some trees can resist ice damage better than others? Certain tree species are more resistant to breakage than others, reducing damage to both trees and property. For example, the dense, springy wood of many oaks breaks less easily than the softer, brittle wood of poplars. It can pay big dividends to do some research before you plant new trees!

Ice storms are caused by super-cooled rain that falls on surfaces, such as tree branches, that are at or below freezing. Accumulations of ice can increase weight on branches to the breaking point and wreak havoc on anything underneath the trees.

Trees with a broad, dense crown and weak, brittle wood, such as flowering plum, are more susceptible to ice damage than trees with narrow crowns, wide branch angles and dense springy wood, such as western red cedar. Dead or diseased limbs are especially vulnerable to breaking when ice accumulates. 

For best resistance to ice breakage, select a tree that is native to the Pacific Northwest. Trees from areas that do not experience ice storms are more susceptible to ice damage because they did not evolve to handle the additional weight – and cold! If you want to use species that are susceptible to ice damage, locate them where falling branches will not pose a hazard to people, structures, transportation routes, or power lines.

Ice storm susceptibility should not be the only reason for selecting trees for landscape plantings, but the numbers of susceptible trees should be limited to areas that will not pose a threat to utilities, buildings, or people.

If you would like a copy of “Trees and Ice Storms; the development of ice storm-resistant urban tree populations,” contact us at urban_forestry@dnr.wa.gov.

An  arborist certified through the International Society of Arborists (ISA) can help evaluate your tree(s) and prescribe the best course of action to treat a tree. You can find a certified arborist near you by looking in the phone book under “tree services” (be sure to look for the ISA Certified Arborist shield), or go to http://www.treesaregood.org/.

Follow DNR on: Facebook Fan See us on Flickr Watch us YouTube Follow us on Twitter Follow DNR Fire Twitter