Common Name: Japanese Hops
Scientific Name: Humulus japonicus Sieb. & Zucc.
Related Species: Common hops (H. lupulus) is a related species used for beer production.
All above and below ground parts of the plant must be destroyed. Additionally, no transportation, propagation, or sale of these plants is allowed. Failure to comply may result in enforcement action by the county or local municipality. Minnesota Noxious Weed Law.
Japanese hops are native to eastern Asia and were introduced to North America as an ornamental in the mid-to-late 1880s. They have escaped cultivation and are displacing desirable species and impeding forest regeneration. Unlike common hops, which is a related species, Japanese hops are not utilized for beer production. Fortunately, there are only a few infestations in Minnesota. The goal is to eradicate infestations before Japanese hops vines spread and become a serious weed issue in Minnesota.
Japanese hops prefers full or partially sunny areas in riparian areas, grasslands, hayfields, and roadsides. It will invade disturbed habitats, but can also colonize undisturbed sites like forest edges and fields.
Japanese hops reproduce by seed that can be dispersed by wind, water, wildlife, vehicles and equipment. View Japanese hops distribution in Minnesota.
Most Japanese hops infestations occur in eastern states, although this species is spreading in the Midwest. In Minnesota, there are two confirmed occurrences in the southeast, one along the Root River and the other along the Mississippi River. The infestation on the Mississippi is just north of a series on infestations in adjacent Iowa and Wisconsin.
Japanese hops grows so rapidly that it can smother other plants. It can form dense patches that outcompete and displace native vegetation. It can spread to cover large areas of open ground or low vegetation including twining around understory trees and shrubs, sometimes causing them to break or fall over.
Many people have an allergic reaction to Japanese hops pollen. In addition, the hooked hairs on the stems and leaves can cause dermatitis and blistering skin after contact.
MDA Noxious Weed Program
County Ag Inspectors
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, firstname.lastname@example.org