Rhamnus cathartica
common buckthorn
Overview
Rhamnus cathartica is a deciduous shrub or small tree reaching 18-25 feet (5.5-7.6 m) tall and 10-18 feet (3-5.5 m) wide, with a spreading crown and often several trunks. The bark is gray-brown, and cut stems reveal orange inner bark and yellow sapwood. Twigs frequently end in a short, sharp spine. Leaves are oval, 1-2.5 inches (2.5-6 cm) long, with finely toothed margins and three to five pairs of curved veins; they stay green late into autumn after most native trees have dropped their leaves. Small yellow-green four-petaled flowers cluster in the leaf axils in late spring, with male and female flowers on separate plants. Female plants bear rounded black drupes about 0.25 inch (6 mm) across, each holding three to four seeds. The fruit has a strong laxative effect on birds, which disperse the seeds across long distances. R. cathartica is native to Eurasia and is regulated as a noxious or invasive species in many U.S. states and Canadian provinces, where it forms dense thickets that shade out native understory plants. It tolerates a broad range of soils, shade, and drought.
Native Range
Rhamnus cathartica is native to Europe, western Asia, and northern Africa. It was introduced to North America in the 1800s as a hedge and ornamental shrub and has since naturalized across much of the northeastern and midwestern United States and southern Canada.Suggested Uses
Rhamnus cathartica was formerly grown as a hedge and windbreak shrub, but that use has ended across its invasive range. It now has no recommended landscape use in North America, where management focuses on removal. Where it persists, the fruit feeds birds that further spread the seed.How to Identify
Appearance
Size & Dimensions
Height18' - 25'
Width/Spread10' - 18'
Bloom Information
Small yellow-green flowers open in late spring, from May into early June, clustered where the leaves meet the stem. Plants are either male or female, so only female specimens set fruit. Black drupes ripen in late summer and may hang on the branches into winter.
Detailed Descriptions
Foliage Description
dark greenGrowing Conditions
Sun Requirements
Tolerates up to 8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
