Amur Honeysuckle (Lonicera maackii)

Description

The Amur honeysuckle is an upright, deciduous shrub distinguished by pairs of fragrant flowers in the leaf axils, hollow stem pith, and pale, shredding bark. Its dark green leaves are elliptic to oblong, come to a sharp, long point, and have hair along the veins on the underside. The flowers are white or pinkish and fade to yellow after blooming in May and June, they bear red fruits. The flower stems are very short and fuzzy. The stems are light tan and become shaggy and hollow with age. The roots are shallow.

Look-alikes

Several native honeysuckles and non-native Japanese honeysuckle grow as vines, not bushes. Native Fly (L. oblongifolia), swamp fly (L. villosa), American fly (L. involucrata), and Canada honeysuckle (L. canadensis) have solid, white piths, and are shorter with sparser branching and foliage. The other invasive Eurasian bush honeysuckles (L. tatarica, morrowii, and x. bella) have more oblong, dull, and slightly hairy leaves. Some Eurasian bush honeysuckles readily hybridize.

Impacts & Habitat

Eurasian bush honeysuckles usually thrive in forests, forest edges, and open grassland areas, especially those that have been grazed or otherwise disturbed. They leaf-out early, lose leafs late, and grow quickly—up to 15 feet in height—forming dense stands that shade the forest floor and out-compete native species for soil moisture and nutrients. Bush honeysuckles may also produce a toxin that inhibits growth of nearby plants. Seeds are eaten and dispersed widely by birds, and appear to require cold stratification to germinate. Seedlings establish in sparse vegetation, usually under tall shrubs or trees. Amur honeysuckle is the dominant bush honeysuckle as far north as central Illinois, but it is currently not yet widespread further north.

Control

Dig and hand pull seedlings, small-to-mid-sized plants, small populations, and areas where herbicides cannot be used at least annually for three to five years. Remove the entire root system. Established stands can be cut and treated with glyphosate (20-25% active ingredient) or basal bark treatment (triclopyr, 12.5% active ingredient). Use foliar applications of glyphosate to seedlings (1% active ingredient) and larger plants (2 % active ingredient). Metsulfuron-methyl plus a surfactant is also effective. Annual prescribed burns are particularly effective during spring leaf-out and once larger plants have been removed from the site.

Additional Information (Links exit DNR)

Invasive Plants Association of Wisconsin
Missouri Department of Conservation
The Nature Conservancy
Plant Conservation Alliance