Popular as a landscape shrub in a variety of settings in both North America and Europe, the Japanese barberry (Berberis thunbergii) is an adaptable shrub that grows in a variety of soil types and sunlight (from full sun to partial shade). These characteristics make it a durable plant for a garden, but other features make it a problem, too. This shrub grows very well all across U.S. Department of Agriculture hardiness zones 4 through 8.
This species of barberry is clothed in hundreds of thin, prickly thorns all over its branches. While a barberry planting near your home foundation may be a nice deterrent from trespassing dogs and burglars, it also isn't the nicest plant to prune or work around. Shrubs near walkways or patios are a nuisance when you must walk by their branches while in shorts or barefoot.
Japanese barberry bears its profusion of tiny yellow flowers in spring, just after the leaves mature. Unfortunately these flowers lead to a tremendous production of seeds that are scattered across garden beds, lawns and eventually into unmanaged natural areas. Moreover, thickets of barberry shrubs that spread their roots near the soil surface will often sprout new plants, exacerbating the spread of the thicket. Eradication of barberry isn't convenient. It has thorny branches, stubborn root segments and numerous seeds and germinating plants. The D&R Greenway Trust cites that barberry can alter soil pH, causing plants nearby to falter, giving the growing barberry an advantage in establishing itself and choking out native plants.
Overuse in the Landscape
The hardiness of barberry–especially the purple or chartreuse foliage varieties of this shrub species–provide an alluring choice for more colorful and aesthetically pleasing landscape designs. It also is a low-maintenance, easy-to-grow plant that tolerates winter cold, droughts and summer heat. With the concerns of invasiveness, it is unethical to continue planting the shrubs. Across much of the northern Unites States Japanese barberry is a common and widespread landscape plant even though many of these states regard it as an invasive plant. Noninvasive plants with either purple or yellow summer foliage can be readily used in its place. Such plants to consider include ninebark (Physocarpus opulifolius), Chinese fringe flower (Loropetallum chinense var. rubrum), and purple-leaf crapemyrtle shrubs–such as cultivar 'Gamad IV'–better known as Ruby Dazzle.