Britt Slattery, USFWS

Japanese Barberry
Berberis thunbergii

Origin: Japan

Background
Japanese barberry was introduced to the United States as an ornamental in 1875. Seeds were sent from Russia to the Arnold Arboretum in Boston, Massachusetts. In 1896, it was planted at the New York Botanic Garden. It was eventually promoted as a substitute for Berberis vulgaris, an exotic plant introduced and used by early settlers from Europe for hedgerows, dyes and jams, and later found to be a host for the black stem rust of wheat.

John M. Randall, TNc

Distribution and Ecological Threat
In the United States, Japanese barberry occurs throughout much of New England and the Northeast, south to North Carolina and west to Michigan and Missouri. Barberry forms dense stands in a variety of habitats, including closed canopy forests and open woodlands, wetlands, pastures, meadows and wastelands. This highly shade-tolerant exotic shrub displaces a variety of native herb and shrub species in areas where it is well established.

Description and Biology

• Plant: a dense, deciduous shrub that grows 2 to 8 feet high. The branches are deeply grooved, brown and usually have simple spines.
• Leaves: 1/2 to 1 1/2 inches long and shaped like small spatulas or narrow ovals, with a color ranging from green to bluish-green to dark reddish purple.
• Flowers, fruits and seeds: flowering occurs from mid-April to May in the Northeast and the fruits mature from July to October and will persist through the winter. The abundant pale yellow flowers occur along the entire length of the stem. Flowers are in clusters of two to four and produce bright red berries about 1/3 inch long.
• Spreads: by seeds eaten by small mammals and birds (e.g. turkey and grouse) and through vegetative means.

Prevention and Control
Do not plant Japanese barberry. Small plants can be pulled by hand, using thick gloves to avoid injury from the spines. A weed wrench ® can be used to uproot older shrubs when soil is moist. Shrubs can also be mowed or cut repeatedly. Treatment with systemic herbicides like glyphosate and triclopyr has been effective.

Native Alternatives

sweet pepperbush (Clethra alnifolia) USFWS	spicebush (Lindera benzoin) Chris Miller, NRCS	highbush blueberry (Vaccinium corymbosum) Britt Slattery, USFWS
northern bayberry (Myrica pensylvanica) Chris Miller, NRCS	swamp rose (Rosa palustris) Chris Miller, NRCS	pasture rose (Rosa carolina) R. Harrison Wiegand

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Publication by USFWS BayScapes Conservation Landscaping Program
http://www.nps.gov/plants/alien/pubs/midatlantic/beth.htm
Last updated: 7 October 2004