This species has been a favorite ornamental shrub in yards, as hedges, and along highways because of its scarlet fruit and orange-red autumn foliage. It has also been used for wildlife plantings and erosion control. It has easily naturalized and spread from cultivated gardens and yards because its seed is often eaten and subsequently distributed by birds.
Japanese barberry is a compact, spiny, deciduous shrub with arching branches of dense foliage. It commonly grows from two to three feet tall and has been known to reach heights of six feet. Branches also root freely when they touch the ground; thus single plants can become quite large. The plant regenerates by seed and creeping roots. Small, rounded, smooth edged leaves are clustered in tight bunches close to the branches. Small yellow flowers bloom in May singly or in small clusters and form bright red oblong berries that mature in mid-summer and persist into winter. Single spines approximately ½" long occur along the stems. The inner bark and roots are yellow.
Well drained soils are preferred by Japanese barberry though it has been found in wetter situations. It typically grows in locations with partial sunlight such as woodland edges. However, it can survive well under the shade of an oak canopy. In young forests it can form thorny thickets that shade out and limit the growth of native plants. It is also often found along roadsides, fence rows, old fields, and open woods.
The primary method of mechanically controlling barberry is by hand pulling or digging early in the season before seed set in areas where there are only a few plants. It is one of the first shrubs to leaf out making identification easier. A hoe, weed wrench, or mattock should be used to uproot the bush and all connected roots. It has shallow roots but resprouting may occur if the entire root system is not removed. Once larger shrubs have been removed from fields, regular mowing should prevent reestablishment.
Herbicides are suggested for plants that are difficult to remove mechanically. Triclopyr has proved effective in controlling barberry when applied as a cut stump treatment. This involves a two step process. First, the plant is cut down close to the ground using a chainsaw, hand saw, or brush mower. While the cut is still fresh the proper solution of triclopyr is applied directly to the cut surface using a low pressure hand held sprayer. This treatment can be applied during any season of the year. Glyphosate is also effective at controlling barberry and can be applied as a cut stump or foliage treatment. Best results are achieved during periods of active growth and full leaf expansion. Care in application, particularly for foliar treatments, is necessary since non-target species can be killed since glyphosate is non-selective.
Prepared by David R. Jackson, Forest Resources Extension Educator