Hedera helix 'Baltica', 'Pittsburgh', and 'Star'; Hedera hibernica 'Hibernica'
Other Common Names: English ivy, Atlantic ivy
Weed class: C
Year Listed: 2002
Native to: No data provided
Is this Weed Toxic?:
not known to be
Why Is It a Noxious Weed?
Ivy can outcompete native plants, reducing animal foraging habitat. It inhibits regeneration of understory plants and kills understory and overstory trees by shading them out. Ivy can cause storm damage trees due to its added weight in the canopy.
How would I identify it?
English ivy is a woody evergreen perennial. It can grow as a vine (juvenile form) or a shrub (adult form). Vines can grow up to 99 feet. In its juvenile form, the plant produces adventitious roots that allow vines to anchor to vertical surfaces.
English ivy only matures to produce flowers when it begins to grow vertically. The small (0.2 to 0.3 inch), bisexual, greenish-white flowers occur in umbrella-like clusters in the fall.
Leaves are alternate and leathery, with long petioles. Juvenile leaves are deeply 3 to 5 lobed and 1.6 to 4 inches long and wide. Flower stem leaves have primarily un-lobed leaves that are egg-shaped to diamond shaped. Only young leaves are hairy.
Stems are climbing vines, shrub-like or groundcovers. Young stems have hairs while older stems are hairless.
Fruit Seed Description
The dark colored fruits (dark blue to black, berry-like drupes) mature in the spring. Each fruit produces 4 to 5 seeds.
May Be Confused With
This listing includes only the known invasive English ivy species and cultivars Hedera helix Baltica, Pittsburgh, and Star; H. hibernica Hibernica.
Where does it grow?
Ivy grows in a variety of landscaped areas, escaping to disturbed forests at a range of elevations. It can grow in a variety of soil types and light conditions. Other habitats include forest edges, fields, hedgerows and coastal areas. Please click here to see a county level distribution map of the four listed cultivars of English ivy in Washington.
How Does it Reproduce?
During its juvenile stage, ivy spreads rapidly by vegetative stem growth while mature plants can also spread by seed. On average, 70% of ivy seeds are viable.
How Do I Control It?
Plants can successfully be pulled by hand or dug out. In the case of plants climbing on trees, vines can be cut at a comfortable height to kill the upper portions of the vine.
Burning plants and re-sprouts at regular intervals with a blow torch will eventually deplete the plant's energy.
For More Information
See our Written Findings for more information about listed ivy species and cultivars (Hedera helix Baltica, Pittsburgh, and Star; H. hibernica Hibernica).
Cowlitz County NWCB Fact Sheet on English ivy
Whatcom County NWCB Fact Sheet on English ivy
Island County NWCB Fact Sheet on English ivy
Jefferson County NWCB Fact Sheet on English ivy
King County NWCB Fact Sheet on English ivy
Mason County NWCB Fact Sheet on English ivy
San Juan County NWCB Brochure on English ivy
Control Options for English ivy from Whatcom County NWCB
Control Options for English ivy from King County NWCB