Japanese Honeysuckle
(Lonicera japonica Thunberg)

How did it get here?

Native to eastern Asia, Japanese honeysuckle was brought to Long Island, N.Y., as an ornamental in 1806. A more aggressive variety was imported to Flushing, N.Y., in 1862. Initially slow to escape cultivation, this vine was established from Connecticut to Florida by 1918.

It is now considered naturalized throughout the eastern and central United States. It has also invaded Hong Kong, England, Wales, Portugal, Corsica, Hawaii, Brazil, and Argentina.

How to spot

Lonicera japonica is a trailing or twining woody vine that is evergreen in most of North Carolina. Vines can reach 30 feet in length. Leaves alternate along the stem and are ovate (young ones may be lobed) and about 1 1/2 to 3 inches long.

Young plants have hairy stems while older ones have smooth, peeling bark. Very fragrant white flowers that fade to yellow are borne in pairs from April through June. Seeds are black berries, produced August through October.

Habitat characteristics

• Sun to partial shade.
• Grows most vigorously on rich, moist soil, but is drought-tolerant.
• Common in disturbed areas such as roadsides, trails, fencerows, and abandoned fields.

Life Cycle

Honeysuckle reproduces by seeds, underground rhizomes, and aboveground runners.

Look-alikes and how to distinguish

• Coral or trumpet honeysuckle (L. sempervirens L.)—leaves joined together around stem (connate); red/orange berries; scarlet red flowers.
• Wild or limber honeysuckle* (L. dioica L.)—leaves joined together around the stem (connate); red/orange berries; pale yellow, orange, or purplish flowers.
• Yellow honeysuckle** (L. flava)–red/orange berries; yellowish to pale-orange flowers.

* rare in North Carolina mountains, endangered in Illinois, Kentucky and Maine, and of special concern in Tennessee.
** rare and local in North Carolina Mountains, endangered in Illinois, of special concern in Tennessee, and extirpated in Ohio.

Why is this plant a problem?

Japanese honeysuckle invades native plant communities following natural or human-induced disturbances such as floods, ice and windstorms; the building of logging roads; or outbreaks of disease.

It grows densely both vertically and horizontally, smothering and shading out native plants and depleting the soil of moisture and nutrients. It disfigures the trunks of trees and topples upright vegetation under the weight of its vines. It can bring down a 13-foot tree in the span of a summer.

Management approaches

• Hand-pull vines in small areas or grub with a shovel or hoe. Bag and discard debris to prevent re-rooting.
• Be vigilant about identifying vines, and control infestations early. It requires about two years to become established, often going unnoticed until it has taken over.
• Mow old fields and roadsides twice yearly to slow spread. But be aware that this will increase stem density.
• Apply herbicides on larger patches. Call your county extension agent or click here for recommendations. Exercise care with the timing of application.

Alternative, native ornamentals

The intoxicating fragrance of Japanese honeysuckle makes it hard for some gardeners and landscapers to shun this vine. But it invades and engulfs treasured plants and trees in landscapes just as it does natural areas, and most people come to regret inviting it.

The honeysuckles and other alternative vines recommended here have arguably better ornamental and wildlife value. Coral honeysuckle and showy trumpet creeper in particular are hummingbird magnets.

VINES:
Coral honeysuckle (L. sempervirens L)
Trumpet creeper (Campsis radicans)
Virginia creeper (Parthenocissus quinquefolia)
NOTE: Cultivated varieties of some of the rare honeysuckles under “Look-alikes” are becoming selectively available at plant nurseries and online retailers.

GROUND COVER:
Wild ginger (Asarum canadensis)

Other resources

Nature Conservancy Element Stewardship Abstract
A wealth of information about biology and control

USDA Natural Resources Conservation Service
National plant database

Virginia Department of Conservation and Recreation, Natural Heritage Program
Fact sheet