Common Name: Japanese honeysuckle
Specific Name: Lonicera japonica
Known Occurrence at Taylor Point:
Map areas: Cliffs 2C, Cliffs 2D, Cliffs 2F, Cliffs 2H, Woodlands 3A, Woodlands 3B, Woodlands 3C, Woodlands 3D, Bridge 4A, Bridge 4B
Category: Invasive, Non-Native, Vine
Ecological Considerations:
Japanese honeysuckle is a woody perennial vine that climbs by twisting its stems around vertical structures, including limbs and trunks of shrubs and small trees. The vines can climb 80 feet high or more and will form a thick covering over trees, shrubs and ground cover species. The leaves are simple, opposite, and oval. The leaf base is round/triangular. Leaves are semi-evergreen to evergreen. The plant’s stems are hairy, reddish/light brown, woody, and hollow. It’s fragrant flowers that ordinarily bloom from April through June are white-cream-pink and fade to yellow. The tubular flowers are paired, arising from leaf axils along stems. It’s fruits are black to purple in color, glossy, paired, producing brown-black seeds.
Problems Posed by this Plant:
Japanese Honeysuckle aggressively grows over native shrubs and trees, choking them, and can also form mat-like monocultures that prevent the establishment of native species. Vigorous root competition also helps Japanese honeysuckle spread and displace neighboring native vegetation.
Native Species Affected by this Plant:
Factors Affording a Competitive Advantage to this Plant:
Japanese Honeysuckle‘s evergreen to semi-evergreen nature gives it an added advantage over native species in many areas. Japanese Honeysuckle competes aggressively below ground for nutrients and above ground for light.
Propagation Mechanisms and Related Issues Affecting Efforts to Remove and/or Eliminate this Plant from Taylor Point:
Birds and other wildlife that consume the fruits disperse Japanese Honeysuckle seeds. The plant’s long vegetative runners frequently tip layer helping to spread the plant locally. The plant propagates underground by rhizomes (stems).
Documented Best Removal Practices and Options/Pros and Cons of Various Options:
Hand-pull the plants, being careful to work out the entire root system. Honeysuckle can re-sprout from severed roots. Repeat and/or mow throughout the growing season. Cut vines from trees at about 4 to 5 feet and gain at ground level to prevent re-sprouts from climbing old vines and to reduce harm to the tree. (Suzanne Enser, TPRA CRMC Permit Request Support Paper)
Methods to control Japanese honeysuckle are both chemical and non-chemical. The effectiveness of their use depends on the extent of the infestation and available time and labor. Hand-pulling seedlings and young plants of Japanese Honeysuckle can be affective if the entire plant is removed. Mowing large patches of honeysuckle may be useful if repeated regularly. Japanese honeysuckle leaves continue to photosynthesize long after most other plants have lost their leaves allowing for the application of herbicides when many native species are dormant.
Case Studies of Removal Efforts, Lessons Learned and Recommendations:
Additional Photos
Sources cited:
MSU
Wiki Japanese Honeysuckle
URI College of Environment and Life Science
Suzanne Enser, TPRA CRMC Permit Request Support Paper
Key Words:
Japanese Honeysuckle
Lonicera japonica
vine