English ivy (Hedera helix)

Synonyms: Hedera arborea, Hedera baccifera, Hedera taurica

Common Names: Common ivy, ivy, Baltic ivy, branching ivy, glacier ivy

Description:

English ivy (Hedera helix) is an evergreen climbing vine from Europe, western Asia, and northern Africa that was brought to North America as an ornamental ground cover [1][2]. It has escaped from gardens into woods and forest edges, where it carpets the ground and climbs high into trees [3][4]. MISIN tracks it because those dense mats smother native wildflowers and tree seedlings, and the climbing vines can weaken and kill the trees they cover [3][4].

Habit:

English ivy is an evergreen vine that does two things: it creeps across the ground in dense mats and climbs up trees, walls, and fences, clinging with many small rootlets along its stems [1][4]. Its leaves are thick, waxy, and dark glossy green, and they come in two shapes ? the familiar 3- to 5-lobed leaves (often with pale veins) on creeping and climbing stems, and plain, unlobed, oval leaves on the sunny flowering stems high in a tree [2][4]. Because it stays green all year, it is easiest to spot in late fall and winter, when it stands out against bare ground and leafless trees [1]. Only the mature climbing stems flower, producing rounded clusters of small greenish flowers in fall and black berries by late winter [4].

At-a-glance cues:

1. Evergreen vine forming dense green ground mats and climbing trees and walls with clinging rootlets [1][4]
2. Thick, waxy, dark-green leaves ? 3- to 5-lobed on creeping and climbing stems, often with pale veins [2][4]
3. Plain, unlobed oval leaves and clusters of small greenish fall flowers on mature climbing stems [2][4]
4. Round black berries in late winter to spring; stays green all through winter [4]

Leaves:

1. Arrangement: alternate along the stems [4]
2. Form: two kinds ? juvenile leaves with 3 to 5 lobes (dark green, often with pale veins) on creeping and climbing stems; mature leaves unlobed and oval to diamond-shaped on sun-lit flowering stems [2][4]
3. Texture: thick, waxy, and leathery; evergreen [4]
4. Color: dark glossy green [4]
5. Surface: smooth, with paler veins on the lobed juvenile leaves [2]

Stems:

1. Habit: a woody evergreen vine that both creeps along the ground and climbs [1][4]
2. Climbing: clings to bark, walls, and fences with many short aerial rootlets along the stem [1][4]
3. Height: can climb 20 to 80 feet or more up trees and structures [4]
4. Color: green when young, turning light brown and woody with age [4]

Flowers:

1. Color: small and greenish-yellow to greenish-white [4]
2. Arrangement: in rounded clusters (umbels), only on mature, sun-exposed climbing stems [2][4]
3. Bloom time: late summer into fall [4]
4. Sex: each flower has both male and female parts [4]
5. Note: a late-season nectar source, but only mature climbing plants flower [4]

Fruit and seeds:

1. Fruit type: clusters of round, black, berry-like fruits about 1/4 inch across [4]
2. Ripening: ripen from late winter into spring [4]
3. Seeds: a few hard, stone-like seeds inside each fruit [4]
4. Dispersal: birds eat the berries and spread the seeds widely [3][4]
5. Note: the berries are poisonous to people ? see Ecological Impact [4]

Habitat:

English ivy grows in forests, forest edges, fields, hedgerows, yards, and coastal areas, and it tolerates deep shade as well as full sun [1][3]. It is native to Europe, western Asia, and northern Africa, and was introduced to North America as a garden plant [1][2]. It does best in moist, rich soil but spreads widely once established, climbing trees and structures and blanketing the ground beneath them [3][4]. It is most aggressive in mild, moist climates but persists across much of the eastern and western United States [1][3].

Reproduction:

English ivy spreads in two ways. On the ground, its stems root wherever they touch soil, so a patch creeps outward, and a cut piece left lying on moist ground can grow into a new plant [4]. It also spreads by seed: only the mature, sun-lit climbing stems flower and make black berries, and birds eat those berries and carry the seeds far from the parent plant ? which is how new ivy appears in woods away from any garden [3][4]. Because a plant must climb into the sun before it can flower and fruit, cutting climbing vines before they reach the canopy keeps a patch from making seed [4]. To stop the spread, remove plants and roots and never dump ivy clippings in natural areas [5].

Impact and Damage:

English ivy can be a health concern around the home. Its black berries are poisonous if eaten ? a risk to children and pets ? and the sap can cause skin redness, itching, and blisters in sensitive people; the leaves and berries are also toxic to dogs, cats, and horses [4]. In a yard, it climbs siding, fences, and trees and is hard to pull off once it has rooted in [4].

In natural areas, English ivy is a serious problem. On the ground it forms a thick evergreen mat that shades out and smothers native wildflowers, ferns, and the seedlings of shrubs and trees, so the forest cannot regrow beneath it [3][4]. When it climbs a tree, it covers the bark and shades the leaves, and the heavy weight of the vines makes the tree more likely to blow down in a storm; over time a heavily covered tree weakens and can die [4]. Dense ivy also lowers the variety of plants and the wildlife they support [3].

Similar species:

English ivy is confused with a few other evergreen or climbing vines; the lobed waxy leaves, clinging rootlets, and evergreen habit help set it apart.

Irish ivy (Hedera hibernica) is nearly identical and also invasive ? it has the same lobed, waxy, evergreen leaves and climbing habit, and the two are told apart only by fine details such as leaf gloss and microscopic hairs [2].

Wintercreeper (Euonymus fortunei) is another evergreen invasive vine that climbs and forms ground mats, but its leaves are arranged in opposite pairs with finely toothed edges, unlike the alternate, lobed leaves of English ivy.

Virginia creeper (Parthenocissus quinquefolia) is a native climbing vine sometimes mistaken for ivy, but it is not evergreen and its leaves are divided into five separate leaflets rather than a single lobed leaf.

Monitoring and rapid response:

Signs to watch for:

1. Dense, evergreen mats of lobed, waxy green leaves carpeting the ground, easiest to spot in late fall and winter [1][4]
2. Vines climbing tree trunks, walls, or fences, clinging with many small rootlets [1][4]
3. Plain oval leaves, greenish fall flowers, and black berries high on climbing stems [2][4]

What you can do:

1. Pull up ground ivy by hand, getting the roots; it comes up most easily in moist soil, and any roots or stem pieces left behind can resprout, so check the spot again [5].
2. To save a tree, cut every climbing vine at the base and again at about shoulder height, then peel the lower band of vine off the trunk; the vines above will die and drop on their own, so there is no need to pull them down [5].
3. Bag the pulled vines and put them in the trash; do not compost them or leave clippings in natural areas, since pieces re-root [5].
4. Plan to return for a few seasons to pull resprouts, and replant cleared ground with native plants so the ivy does not simply grow back [5].
5. Natural-area crews work the same way at larger scale, freeing the most valuable trees first and clearing ground mats outward from the edges [5].

When to call a professional:

1. Large, well-established stands, tall vines high in valuable trees, or ivy on steep or hard-to-reach ground [5].
2. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USDA NRCS Plants Database. Hedera helix L. (English ivy, symbol HEHE). plants.usda.gov
2. Plants of the World Online (POWO), Royal Botanic Gardens, Kew. Hedera helix L. powo.science.kew.org
3. California Invasive Plant Council (Cal-IPC). Hedera helix profile. cal-ipc.org
4. North Carolina State Extension, Gardener Plant Toolbox. Hedera helix (English ivy). plants.ces.ncsu.edu
5. North Carolina State Extension. Controlling English Ivy in Urban Landscapes. content.ces.ncsu.edu

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