English/Irish Ivy

English/Irish Ivy

Scientific name: Hedera helix Hedera hibernica

Common names: English Ivy, Atlantic Ivy, Irish Ivy

Description: English/Irish ivy are evergreen vines that trail on on the ground and climb trees, fences, and other structures. Imported from Europe for use in landscaping, they have established in disturbed areas as well as relatively remote forests throughout the Pacific Northwest. They have dull green, lobed leaves that vary in shape and size according to variety. As the plant matures, its leaves turn shiny green, it produces small yellow-green flowers, and purple-black berries.

Impact: The berries of these invasive ivys are easily spread by many common birds, despite being poisonous for some species of birds. Once spread, the seeds are able to sprout in a wide variety of soil and sunlight conditions, thus allowing them to invade shaded forest areas. With no natural competitors in the region, English/Irish ivy are able to grow unchecked and outcompete native vegetation, often forming dense mats in the forest understory. These mats can host pest animals such as the Norway rat and increase slope erosion. As the vines climb on structures, they can integrate into wood/mortar and cause damage. When vines climb trees, they increase the risk of the tree being blown over and damage tree health through increased risk of bark disease and competition for light. Mature vines can grow up to 5 inches in diameter, making them very difficult to remove.

Source: KingCounty.gov

For more information, please visit the Noxious Weed resources at KingCounty.gov: http://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification/english-ivy.aspx