Description of Japanese Barberry
· woody shrub with arching branches
· average size of 2-3 feet; as tall as 6
· stems have a single spine below each rosette of untoothed leaves
· yellow flowers have four sepals with modified leaves below petals
· sepals and petals are similar in appearance
· flowers produce small, oblong red berries, found singly or in clusters
· inner bark and roots are yellow
Though a pretty plant, Japanese barberry (Berberis thunbergii) is an invasive woody shrub known to infiltrate forests, wetlands and other natural areas and bully out native plants.
Native to Japan, Japanese barberry settled in North America in the late nineteenth century. It quickly became popular for ornamental hedges with its yellow flowers in the spring, brilliant fall coloring and small, oblong red berries in the winter. It was also easy to cultivate; maybe too easy. As its fruits are often eaten by birds, the plant has easily naturalized and has established colonies outside cultivation that grow thick and crowd out native plants.
Japanese barberry is so successful in overpowering native species because it appears to alter soil pH and nitrate levels, creating conditions that are beneficial for its growth alone. White-tailed deer avoid it, choosing to eat nearby native species while birds enjoy the bright red berries throughout the winter, giving barberry an unfair competitive advantage.
Controlling Japanese Barberry
In the past several years, Japanese barberry has become a growing concern in Indiana. If left unchecked, its invasion on our natural areas will persist and the more expensive it will be to control it. Luckily it is one of the first plants that leaf out in early spring making it easily distinguishable from other shrubby plants.
According to The Nature Conservancy's Connecticut Chapter, mechanical removal of this invasive species is recommended as it is both effective and minimally intrusive. Use a hoe, weed wrench or mattock to uproot the entire bush and associated roots. The uprooted shrubs can be piled as cover for small animals if you choose. Plants growing in rock piles, however, are more difficult to dig out and are often treated with the herbicide glyphosate - a non-selective herbicide that will not harm native plants if used carefully.
Unfortunately, Japanese barberry is still available for purchase in greenhouses and nurseries. However, there are plenty of beautiful native alternatives to plant instead of this bully of an invasive species. MIPN, or the Midwest Invasive Plant Network (MIPN) published a helpful guide on landscape alternatives for invasive species and Japanese barberry. A few recommendations include: littleleaf linden (Tilia cordata), winterberry holly (Ilex verticillata) and redleaf rose (Rosa rubrifolia).