Saturday, September 16, 2017
English ivy is a rapidly growing evergreen vine typically seen growing on hillsides, climbing trees, growing over fences and up the sides of houses. It out-competes other plants for soil, sunlight and water. English ivy can kill large trees by suffocating their trunks and weighing down branches. A mature English ivy plant can weigh up to 2,100 pounds, with trunk-like stems that can be nearly a foot thick.
To identify English ivy, look for year-round waxy green leaves and trailing vines. The leaves can be lobed and typically have whitish veins. In late summer or early fall, the mature plant will produce greenish-yellow, starburst flowers at the end of the flowering stem. Berries are black with a fleshy outer layer and stone-like seeds.
English ivy reproduces both from seeds and from stem fragments. Birds feed on the berries and distribute the seeds in their droppings wherever they fly. Stem fragments that come in contact with the ground will also easily re-root and start a new plant.
This vine is an aggressive invader growing in the canopy of trees as well as on the ground. It out competes native vegetation and reduces animal habitat. It destabilizes streambanks and hillsides as its shallow roots don’t hold the soil as well as native plants. Rats and other vermin are able to hide in the cover of English ivy and use the vines to access our homes.
English ivy is best treated by hand-pulling vines. Cut all berry producing branches and keep vines away from trees — do not let the plant climb. If it has climbed into the trees, cut the vines at the ground and again 4-5 feet up the tree, removing those sections. Pulling long vines off of tree branches is difficult and may damage the trees.
Dispose of ivy by bagging and placing it in the garbage. Larger vines can be cut and stumps treated with herbicide (ask your OSU Extension master gardeners for more information).
Jordan Kim is director of Hood River Soil and Water Conservation District.