Origin: A native of East Asia, this plant was introduced to the United States from Japan in the early 1800s as an ornamental. It has also been planted for wildlife forage and cover and for erosion control.
Description: Japanese honeysuckle is a perennial, evergreen or semi-evergreen vine which climbs by twining around structures. In areas with milder winters, it will typically keep its leaves all year. Where winters are colder, it may lose its leaves but will keep them later into the year than native plants. Leaves are around 2 inches long and are opposite and oval but may be lobed in early spring. They are whitish underneath and may be smooth or hairy. Paired flowers are present from April to August. These are tubular, flaring into 2 lips, with the upper lip consisting of 4 fused petals. They are white or pink, turning pale yellow with age, are about 1 inch long, and are very fragrant. Fruits are berries that ripen to black. Young stems are red-brown and hairy; older stems are hollow. Japanese honeysuckle resembles Asian bush honeysuckles.
Habitat description: This perennial vine grows well along woodland edges in partial to full sun. Often keeping greenish-purple leaves during mild winters, this vine grows almost year-round. Found overtopping shrubs and small trees, it will form dense thickets. Its love for "edge" environments often finds it growing in conjunction with Autumn Olive. A healthy tangle of this vine can be seen smothering native vegetation on the North side of SR 46 across from the Salt Creek golf course.
Distribution: This invasive vine is shade tolerant and can be found in dense infestations in a wide variety of habitats including forest edges, right-of-ways, wetlands, fields, under forest canopies, and in all types of disturbed areas.
Problem: Japanese honeysuckle spreads rapidly by rooting at nodes on its stems and by animal-dispersed seeds. It can kill the shrubs and trees it climbs by cutting off their water supply as it wraps tightly around them, or by forming a dense mat on top of them and shading them out. It can also displace native plants through root competition.
Control: Hand-pulling of seedlings or small plants may be effective, but care should be taken not to disturb the soil more than necessary. Glyphosate (3%) or triclopyr (3%) may be sprayed onto leaves. This can be done anytime during the growing season, but may be best in the early fall when native plants are dormant, but the target plant is still green and physiologically active. Winter treatment may be possible if green leaves are still present and the high temperature exceeds 50? F. When applying herbicide to a plant with waxy leaves, consider adding 0.5% non-ionic surfactant to the herbicide mix if recommended on the herbicide label.
USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use requirements, restrictions or recommendations.