Mechanical removal is recommended because it is effective and may cause the least disturbance. Japanese barberry is one of the first plants to leaf out in spring and is therefore easy to distinguish from other shrubs. Whole shrubs may be removed with a hoe or weed wrench. Use of thick or sturdy gloves is recommended to provide protection from the spines. Plants can resprout from roots, so remove as much of the roots as possible. Regular mowing can prevent barberry from returning once it has been removed. In areas where mechanical removal is not practical, such as rock piles or outcrops, a glyphosate herbicide can be used (painted, not sprayed on cut stumps).
Berberis thunbergii is a dense deciduous shrub 0.5-2.4 m (2-8 ft.) tall. It flowers from mid April to May in the Northeast and its fruits mature from July to October. The branches are glabrous, deeply grooved, brown and have usually simple spines. The leaves are glaucescent underneath, spatulate or narrowly obovate in shape, and are 1.3-3.8 cm (0.5-1.5 in.) long. They range in color from slightly bluish-green to green to dark reddish purple. The pale yellow flowers of Berberis thunbergii are profuse and located along the entire length of the stem. The inflorescences are umbellate with the 8 mm (0.3 in.) long flowers in clusters of 2-4. Bright red berries 7-9 mm (0.28-0.35in.) in length are elliptic or nearly globose in form. The fruits are slightly juicy but solid, and persist on the stems until the following spring.