Bill Johnson

Morrow’s Honeysuckle

Lonicera morrowii A. Gray
Honeysuckle family (Caprifoliaceae)

Origin: Japan and South Korea

Background
Morrow’s honeysuckle was imported in the 1800s for use as an ornamental, for wildlife food and cover as well as for soil erosion control. Widely planted through the 20th century it is recognized as highly invasive species impacting natural areas as well as managed parks, gardens and other lands.

Distribution and Habitat
Morrow’s honeysuckle is fairly common in the mid-Atlantic region, often co-occurring with Amur honeysuckle. It is found from Wisconsin to Maine and Missouri to North Carolina. It is shade tolerant but will flower and fruit more in full sun. Morrow’s honeysuckle invades forest edges and interiors, floodplains, pastures, old fields, roadsides and other disturbed areas.

Ecological Threat
Morrow’s honeysuckle forms dense thickets and outcompetes and displaces native shrubs, trees and herbaceous plants. Its dense growth can impede reforestation efforts. It invades open woodlands, old fields and other disturbed sites and can spread rapidly with help from birds and mammals which disperse its seeds. Like Amur honeysuckle, Morrow’s honeysuckle likely also encourages increased nest predation due to its branching structure. While the fruits of exotic honeysuckles provide some nutrition for birds and mice in winter, their carbohydrate-rich quality is no match for the lipid-rich fruits of many native species that sustain migrating birds.

Description and Biology

• Plant: multi-stemmed, upright, deciduous shrub that grows to 7 ft. tall; pith of mature stems is hollow and white or tan in contrast to solid white pith of native shrub honeysuckle species.
• Leaves: opposite, 1-2 in. long, elliptic to oblong, on short stalks, sparsely hairy above, permanently hairy underneath.
• Flowers, fruits and seeds: flowers are paired, borne from leaf axils, white, tubular (lower half) with 5 separate (unfused) petal lobes, spring (late April-early May); fruits paired, red to orange, many-seeded berries mature in July and persist through the winter.
• Spreads: by seed which is spread by birds that consume the fruits and defecate the seeds in new locations; vegetative sprouting aids in local spread.
• Look-alikes: native bush honeysuckles (Diervilla sp.), hairy honeysuckle (L. hirsuta), swamp fly-honeysuckle (L. oblongifolia) and water-berry (L. villosa).

Prevention and Control
Young plants can be pulled by hand, larger plants either pulled using weed wrench-type tool or cut repeatedly. Systemic herbicides containing glyphosate or triclopyr can be applied to foliage, bark or cut stems (see Control Options).

Native Alternatives
Other native honeysuckles including American fly honeysuckle (L. canadensis), swamp fly-honeysuckle (L. oblongifolia) and mountain fly honeysuckle (L. villosa) and the related northern bush-honeysuckle (Diervilla lonicera) can be alternatives for Morrow’s honeysuckle.