Japanese barberry is a spiny deciduous shrub that can reach 6 feet in height. Leaves are small and oval with smooth margins. There are two common color morphs, a dark-green and deep-purple variety. The green form is usually associated with shaded sites, while the purple morph is more common in full sun. Japanese barberry has a single spine at each node where the leaves meet the stem. Flowers are very small, white to yellow in color, and bloom in April or May. Fruits are small oval bright-red berries that are approximately 1cm long. The inner roots and stem of Japanese barberry are vibrant yellow in color.
Japanese barberry closely resembles another invasive shrub, common barberry (Berberis vulgaris).
Confirmed observations of Japanese barberry submitted to the NYS Invasive Species Database. For more information, visit iMapInvasives
Japanese barberry is a common ornamental species used in commercial and residential landscaping. It easily escapes into natural areas via bird dispersed seeds where it can dominate forest understories and riparian corridors.
Threats & Impacts:
Japanese barberry is capable of long distance dispersal via bird and animal deposited seeds. With numerous sharp spines, herbivorous animals will not feed on barberry when it invades natural areas. As a result, native species are overgrazed and Japanese barberry dominates the landscape.
The dense growth form of Japanese barberry creates a suitable refuge for small mammals such as field mice. An increased abundance of rodents, coupled with increased humidity within the shrubs dense growth form, creates an environment that is highly desirable to ticks. Forests invaded with Japanese barberry have been documented to contain up to 10 times the quantity of Lyme infected ticks as a similar uninvaded forest.
Do not plant Japanese barberry. Small plants can be hand-pulled or removed using a weed wrench prior to seed set. Larger infestations are most efficiently treated using an herbicide. Glyphosate can be used as a cut stump or foliar spray application, while triclopyr may be applied via cut stump, basal bark, or foliar spray.