Synonym(s): Lonicera japonica var. chinensis, Nintooa japonica
Family: Caprifoliaceae (Honeysuckle Family)
Duration and Habit: Perennial Vine
Semievergreen to evergreen woody vine, high climbing and trailing to 80 feet (24 m) long, branching and often forming arbors in forest canopies and/or ground cover under canopies and forming long woody rhizomes that sprout frequently.
Ecological Threat: In North America, Japanese honeysuckle has few natural enemies which allows it to spread widely and out-compete native plant species. Its evergreen to semi-evergreen nature gives it an added advantage over native species in many areas. Shrubs and young trees can be killed by girdling when vines twist tightly around stems and trunks, cutting off the flow of water through the plant. Dense growths of honeysuckle covering vegetation can gradually kill plants by blocking sunlight from reaching their leaves. Vigorous root competition also helps Japanese honeysuckle spread and displace neighboring native vegetation.
Biology & Spread: Growth and spread of Japanese honeysuckle is through vegetative (plant growth) and sexual (seed) means. It produces long vegetative runners that develop roots where stem and leaf junctions (nodes) come in contact with moist soil. Underground stems (rhizomes) help to establish and spread the plant locally. Long distance dispersal is by birds and other wildlife that readily consume the fruits and defecate the seeds at various distances from the parent plant.
History: Introduced from Japan in the early 1800s. Traditional ornamental, valued as deer browse, with some value for erosion control. Still planted in wildlife food plots.
U.S. Habitat: Most commonly occurring invasive plant, overwhelming and replacing native flora in all forest types over a wide range of sites. Occurs as dense infestations along forest margins and right-of-ways as well as under dense canopies and as arbors high in canopies. Shade tolerant. Persists by large woody rootstocks and spreads by rooting at vine nodes and animal-dispersed seeds.
U.S. Nativity: Introduced to U.S.
Native Origin: E. Asia (Alfred Rehder, Manual of Cultivated Trees and Shrubs: Hardy in North America, The MacMillan Co., New York (1967), Bailey, L.H. and E.Z. Bailey, Hortus Third: A Concise Dictionary of Plants Cultivated in the United States and Canada, MacMillan Publishing Co., Inc., New York , (1977).); NatureServe Explorer
U.S. Present: AL, AR, AZ, CA, CT, DE, FL, GA, HI, IL, IN, KS, KY, LA, MA, MD, ME, MI, MO, MS, NC, NE, NH, NJ, NM, NV, NY, OH, OK, PA, PR, RI, SC, TN, TX, UT, VA, WI, WV
List All Observations of Lonicera japonica reported by Citizen Scientists
Vines that make good substitutes for Japanese honeysuckle include false jasmine (Gelsemium sempervirens), trumpet honeysuckle (Lonicera sempervirens), trumpet creeper (Campsis radicans), crossvine (Bignonia capreolata), native wisteria (Wisteria frutescens), jackman clematis (Clematis jackmanii), and others.
Several effective methods of control are available for Japanese honeysuckle, including chemical and non-chemical, depending on the extent of the infestation and available time and labor.
Manual and Mechanical
For small patches, repeated pulling of entire vines and root systems may be effective. Hand pull seedlings and young plants when the soil is moist, holding low on the stem to remove the whole plant along with its roots. Monitor frequently and remove any new plants. Cut and remove twining vines to prevent them from girdling and killing shrubs and other plants. An effective method for removal of patches of honeysuckle covering the ground is to lift up and hold a portion of the vine mass with a rake and have a chain saw operator cut the stems low to the ground. Mowing large patches of honeysuckle may be useful if repeated regularly but is most effective when combined with herbicide application (see below). Mow at twice a year, first in mid-July and again in mid-September. Plants can also be grubbed out using a pulaski or similar digging tool, taking care to remove all roots and runners. Burning removes above ground vegetation but does not kill the underground rhizomes, which will continue to sprout. In certain situations, tethered goats have been used to remove honeysuckle growth, but must be monitored to prevent their escape to the wild where they would become an added ecological threat.
In moderate cold climates, Japanese honeysuckle leaves continue to photosynthesize long after most other plants have lost their leaves. This allows for application of herbicides when many native species are dormant. However, for effective control with herbicides, healthy green leaves must be present at application time and temperatures must be sufficient for plant activity. Several systemic herbicides (e.g., glyphosate and triclopyr) move through the plant to the roots when applied to the leaves or stems and have been used effectively on Japanese honeysuckle.
Following label guidelines, apply a 2.5% rate of glyphosate (e.g., Rodeo? for wetlands; Roundup? for uplands) mixed with water and an appropriate surfactant, to foliage from spring through fall. Alternatively, apply a 2% concentration of triclopyr (e.g., Garlon 3A) plus water to foliage, thoroughly wetting the leaves but not to the point of drip-off. A coarse, low-pressure spray should be used. Repeat applications may be needed. Treatment in the fall, when many non-target plants are going dormant, is best. Also, a 25% glyphosate or triclopyr solution mixed with water can be applied to cut stem surfaces any time of year as long as the ground is not frozen.
No biological control agents are currently available for Japanese honeysuckle.
Barden, L. S. and J. F. Matthews. 1980. Change in abundance of honeysuckle (Lonicera japonica) and other ground flora after prescribed burning of a piedmont pine forest. Castanea 45: 257-260.
Dillenberg L.R., D.F. Whigham, A.H. Teramura, I.N. Forseth. 1993. Effects of below- and aboveground competition from the vines Lonicera japonica and Parthenocissus quinquefolia on the growth of the tree host Liquadambar stryraciflua. Oecologia 93:48-54.
Fernald, M. L. 1989. Grays Manual of Botany. Biosystematics, Floristic and Phylogeny Series. Volume 2. T. R. Dudley, Editor. Dioscorides Press. Portland, OR. 1,632 pp.
Gleason H. A. and A. Cronquist. The Illustrated Companion to Gleason and Cronquist's Manual of Vascular Plants of Northeastern United States and adjacent Canada. New York Botanic Garden, New York, NY. 937 pp.
Kartesz, J. and C. Meacham Synthesis of the North American Flora.
Nuzzo, V. Japanese honeysuckle. Element stewardship abstract for Lonicera japonica. The Nature Conservancy. 1815 North Lynn Street, Arlington VA, 22209. www.tncweeds.ucdavis.edu/esadocs.documnts/lonijap.html. Last updated April 15, 1997.
Regehr, D. L. and D. R. Frey. 1988. Selective control of Japanese honeysuckle (Lonicera japonica). Weed Technology 2:139-143.
Rhoads, A. F. and T. H. Block. 2002. The Plants of Pennsylvania, An Illustrated Manual. Morris Arboretum of the University of Pennsylvania. University of Pennsylvania Press, Philadelphia, PA. 1060 pp.
Virginia Native Plant Society VA NHP Japanese Honeysuckle Fact Sheet http://www.vnps.org/invasive/invloni.htm
APWG WeedUS Database
Miller, J.H. 2003. Nonnative invasive plants of southern forests: a field guide for identification and control. Gen. Tech. Rep. SRS-62. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 93 pp (USDA SRS).
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