Four Sterile or Near-sterile Cultivars of Japanese Barberry in Three Foliage Colors

Berberis thunbergii L. (Japanese barberry) holds significant market share in the commercial ornamental horticulture industry. Japanese barberry is grown by production nurseries and used in landscaping across the northern half of the United States. In 2009, the barberry crop was worth nearly $30.5 million in annual sales in the United States, making it one of the top two ornamental shrubs, roses excluded. [U.S. Department of Agriculture (USDA) 2009]. Dirr (2009) lists close to 70 cultivars of B. thunbergii or B. thunbergii hybrids, and new cultivars continue to be introduced at a rapid rate. Hardiness, ease of culture, resistance to deer browse, compact habit, and general attractiveness have made Japanese barberry one of the most popular landscape shrubs in the United States (Steffey, 1985). Japanese barberry cultivars offer ornamental interest in all four seasons, featuring yellow flowers in spring; attractive red, yellow, green, or variegated foliage in summer; leaves that turn orange, yellow, and red in fall; and bright red berries that persist through the winter (Steffey, 1985). Its thorny stems make it useful as an impenetrable hedge in home landscapes (Steffey, 1985), and other uses include foundation plantings, groupings and even as a specimen for difficult growing conditions (Dirr, 2009). Japanese barberry’s popularity as a commercial horticulture staple crop has also resulted from its ease of culture under production nursery conditions (Mark Sellew, Prides Corner Farms, Lebanon, CT, personal communication). Barberry roots easily from cuttings; thus large numbers of genetically uniform plants may be raised (Dirr and Heuser, 2006), and it only requires one to two growing seasons to reach saleable size in a container.