Japanese honeysuckle is a common invasive weed in Delaware. The following are some control recommendations.
Japanese Honeysuckle, Lonicera japonica, is in flower across Delaware. Leaves are mostly oval to somewhat lobed, opposite, in pairs. Honeysuckle often remains evergreen through the winter. Flowers are tube shaped, white to pink, turning yellow with age and occur in pairs along the stem at leaf axils. They have a distinctive fragrance. This invasive woody vine is common along wood edges, ditch banks, roadsides, fence lines, low maintenance areas, and right of ways. It was introduced in the early 1900’s from the Far East. It is an aggressive climber and can smother desired shrubs and trees and cover fences or posts.
Control small patches by hand digging. Mowing repeatedly is partially effective on large areas. Mow twice, one in July, again in September and repeat each year. In areas where it is climbing vegetation,cut at the base and remove vines. Apply a herbicide to cut stems. Use a 50% glyphosate herbicide or 25% triclopyr herbicide solution (based on formulated products such as Roundup or Garlon). Foliar applications of a 1-5 to 2.5 % glyphosate or a 2% triclopyr herbicide (formulated product) sprayed to runoff can provide control but repeated applications may be needed. Treat in the fall, when non-target plants are going dormant. Avoid contact with desired plants that are still in leaf.
Gordon Johnson, Extension Horticulture Agent, UD