English ivy (Hedera helix) grows as a vigorous, often invasive, evergreen woody vine. The vine utilizes tiny root-like tentacles that secrete a sticky substance which enables the plant to cling to a multitude of surfaces. The stems of the English ivy vine can grow quite large, up to a foot in diameter. Leaves appear with three to five lobes that range in color from solid green to variegated varieties.
When English ivy reaches 10 years of age it produces small yellow flowers in large clusters. Flowers appear in the fall and attract not only bees but also an abundance of flies.
Following flowering, tiny dark purple fruit appear. Each tiny berry contains one to three seeds. The berries are often consumed by birds. If consumption does not occur the berries persist on the vine into the winter months. The fruit contains glycoside hederin, which is toxic to humans and often causes gastric upset. In birds, the berries appear to have a laxative effect, which enables widespread seed dispersal to occur as the bird eliminates.
English ivy is extremely invasive. The vigorous growth of the vine overtakes plants, underbrush, shrubs and trees as the vine climbs toward the sunlight. The vine quickly engulfs an entire tree and kills the limbs until the tree dies. Trees covered in ivy pose a dangerous problem because they are more prone to falling in heavy winds. As English ivy spreads across the ground it overtakes and kills all native plant life. Currently, 18 states report to have a serious problem with the vines invasion, according to the National Park Service.
English ivy grows in forests, salt marshes, coastal areas, fields and even alongside roadways. The ivy thrives in moist, acidic soil conditions.
English ivy was brought to the United States from Europe by setters who immigrated into North America. The ivy was widely planted as an ornamental. Today it still persists as a popular landscape plant that is favored by the homeowner and business owners for its fast growth and pleasing appearance. The plant is also widely grown as a houseplant.