Morrow Honeysuckle is an invasive plant similar to our native honeysuckles.

Mary Blickenderfer, Regional Extension Educator, University of Minnesota Extension Service, (218) 327-4616While common and glossy buckthorn get most of the attention and bad press for their large-scale invasion and ultimate destruction of native plant communities, Eurasian honeysuckles are in the same league. Most aggressive in our area are tartarian honeysuckle (Lonicera tatarica), Morrow honeysuckle (Lonicera morrowii), the hybrid of these two species (Lonicera x bella), and amur honeysuckle (Lonicera maackii). In addition to these shrubs, the Japanese honeysuckle vine (Lonicera japonica) was “introduced (with good intentions but disastrous results) from southern Asia, now in many places an aggressive vine that defies eradication, forming dense tangles that overwhelm the native (or other) vegetation” (Voss 1996). Control of these honeysuckles requires laborintensive mechanical (pulling, mowing, burning) or chemical (herbicide) treatment. Mature shrubs should be removed first, followed by ongoing treatment of the seedlings that may re-sprout from roots or germinate from seeds in the soil.

In contrast to their European cousins are several honeysuckles native to our area, none of which are aggressive invaders. Bush-honeysuckle (Diervilla lonicera) and glaucous honeysuckle (Lonicera dioica) occur in woods and thickets throughout Minnesota. Fly honeysuckle (Lonicera canadensis), hairy honeysuckle (Lonicera hirsuta), northern fly honeysuckle (Lonicera villosa) and swamp fly honeysuckle (Lonicera oblongifolia) occur in the northern part of the state.

You may be wondering if you have an invasive honeysuckle in your back yard, and how you tell it from the native honeysuckles. As a general guideline, the non-native honeysuckle shrubs are large (5-12’ high), have opposite leaves, and produce delicate white-pink flowers that become bright red (may be orange to yellow) pea-size berries situated in pairs in the leaf axils (where leaves attach to stem). The native honeysuckles are low inconspicuous shrubs (or vines), have opposite leaves, but produce yellow flowers that become pairs of cone-shaped red berries (Lonicera canadensis), narrow capsules (Diervilla lonicera), or peasize red or blue/purple berries. Consult a plant key or plant expert for positive identification.

One final note: don’t eat the berries of the non-native honeysuckles! They are bitter and some contain an unknown poison that causes violent vomiting and bloody diarrhea (Holmaasen 1989).

References:

• Holmaasen, I. 1989. Traed och Buskar. Stockholm: Interpublishing. 176pp.
• Voss, E. 1996. Michigan Flora. Ann Arbor: Cranbrook Institute of Science. 622pp.

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