USDA, NRCS

English Ivy
Hedera helix

Origin: Europe, Western Asia and Northern Africa

Background
European immigrants likely introduced English ivy to the United States. It is extremely popular and widely planted because of its evergreen foliage and dependability as a year-round ground cover. Although widely recognized as a serious pest of natural areas, it continues to be sold as an ornamental plant in the United States.

Distribution and Ecological Threat
English ivy occurs throughout the eastern United States, across the southern states and up to Washington State. It is one of the most abundant and insidious invasive plants, as it threatens all vegetation levels of forested and open areas, growing along the ground as well as into the tree canopy. English ivy infests woodlands, forest edges, fields, hedgerows, coastal areas, salt marsh edges and other upland areas, especially where some soil moisture is present. As a ground cover, the dense growth and abundant leaves form a thick canopy just above the ground that prevents sunlight from reaching herbs and seedlings. Vines that climb up trees slowly kill the tree from the base upwards by enveloping branches and twigs, blocking sunlight, causing branch and eventual tree death. The added weight of vines also makes trees susceptible to blowing over during storms. English ivy has been confirmed as a reservoir for bacterial leaf scorch (Xylella fastidiosa), a harmful plant pathogen that affects a wide variety of native and ornamental trees such as elms, oaks and maples.

Description and Biology

• Plant: an evergreen climbing vine in the ginseng family (Araliaceae). Vines attach to the bark of trees and other surfaces by way of numerous, small, root-like structures, which exude a glue-like substance; older vines can reach a foot in diameter.
• Leaves: dark green, waxy, somewhat leathery, arranged alternately along the stem; leaf forms are extremely variable with the most recognized leaf form being three-lobed.
• Flowers, fruits and seeds: when sufficient light is available, umbrella-like clusters of small, greenish-white flowers are produced in the fall on flowering branches that extend out at right angles from clinging vines; fruits and are black with a fleshy outer layer and mature during the following spring; seeds are stone-like.
• Spreads: reproduces vegetatively and by seed, which is dispersed to new areas primarily by birds. English ivy contains glycosides that cause some birds to vomit and disseminate seeds. New plants grow easily from cuttings or stem fragments that make contact with the soil.
• Look-alikes: Boston ivy (Parthenocissus japonicus) is sometimes confused with English ivy.

Prevention and Control
Do not plant English ivy. Vines on the ground can be pulled up by hand, with some difficulty and bagged and disposed of as trash. Vines climbing up trees should be cut to kill upper portions and relieve the tree canopy. Portions of vines rooted in the ground will remain alive and will need to be treated with herbicide or cut repeatedly until no re-growth occurs. A systemic herbicide like triclopyr may be applied to foliage or cut stems. There are no biological controls currently available for English ivy.

Native Alternatives
Vines:

Virginia creeper (Parthenocissus quinquefolia) Britt Slattery, USFWS

crossvine (Bignonia capreolata) Britt Slattery, USFWS

Groundcovers (use alone or mix for diversity and sustainability):

wild ginger (Asarum canadense) Britt Slattery, USFWS	lady fern (Athyrium filix-femina) Kenneth J. Sytsma, UWI	foam flower (Tiarella cordifolia) Britt Slattery, USFWS
partridgeberry (Mitchella repens) Britt Slattery, USFWS	creeping phlox (Phlox stolonifera) Britt Slattery, USFWS	evergreen wood fern (Dryopteris marginalis or intermedia) Emmet J. Judziewicz, UWI

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Publication by USFWS BayScapes Conservation Landscaping Program
http://www.nps.gov/plants/alien/pubs/midatlantic/hehe.htm
Last updated: 7 October 2004