While we sometimes think of ivy and other climbing vines as harmless groundcovers, they are anything but harmless to trees. English ivy wreaks more havoc on our local native ecosystem than probably any other invasive species. Listed as a noxious weed in the state of Washington, ivy is costly to control, nearly impossible to eradicate, and creeps so subtly in to the landscape that the damage it causes often becomes irreversible before it is even noticed.
The shade created by the growth of ivy into the canopy of a tree can kill the tree by disrupting the process of photosynthesis; or ivy can develop into such a dense matte that the tree simply falls over from the weight (the estimated weight of ivy removed from one tree in Olympic National Park was 2100 pounds!). It can also kill a thin-barked tree by slowly strangling its stem. At a minimum, ivy that has been allowed to become established in a tree can cost hundreds or even thousands of dollars to remove.

Whenever possible prevent ivy from growing into your trees or, better yet, eliminate it from your landscape altogether. If you observe it growing into trees in your local park, do the trees and your neighbors a favor by taking the time to sever the ivy at the base of the tree (using caution to avoid cutting into the tree trunk) and you will have at least halted further damage.

Marc Castoriano
marc@natureshelpernw.com