The Invasive Japanese Honeysuckle

Japanese honeysuckle was brought to the United States, along with other non-native honeysuckles, such as Tatarian (Lonicera tatarica), as an ornamental plant. Like many invasive species, Japanese honeysuckle (Lonicera japonica) likes to grow along the edge of a disturbance (wood edge, path). It prefers full sun, but it can grow in shaded environments. This plant reproduces by seed or from the runners that can root at the node. Growth is aggressive, and the plant will climb over other desirable plant material. The foliage has an opposite orientation. Young leaves have smooth lobes and are narrow and elongate. Mature leaves are oval with smooth edges with hairs on the surface. In northern areas, Japanese honeysuckle drops its foliage. In warmer areas, it is semi-evergreen to evergreen. The white, ornate flowers appear in the spring and are very fragrant. The seeds are dispersed in black fruit.

Like all woody invasive species, Japanese honeysuckle requires time and effort to remove. Seedlings can be removed by hand. Due to its climbing nature, using a mower for management could be a problem. In late summer, mowing (if possible) or cutting the vines needs to be followed up with an application of concentrated herbicide (glyphosate or triclopyr) to the cut wood. You can also cut the plants in mid to late summer, wait for the plants to regrow, and then spray the new foliage. Foliar applications of glyophosate or triclopyr can also be applied, but if this is done early in the growing season, further monitoring will be required to watch for regrowth. Remember to always read the label for specific application sites, precautions, and mix rates.