Common buckthorn identification
Common Buckthorn (Rhamnus cathartica) is a small, shrubby tree. Its poisonous, small, black berries are often mistaken for wild black cherries. This non-native plant has become a weedy nuisance in woodlands and fence rows, competing with more desirable native trees and shrubs. It also serves as an alternate host for oat crown rust. We no longer recommend planting it.
In the past, Common Buckthorn was more widely planted for formal hedges. It is now more commonly encountered as a wild plant. Birds spread the seeds after eating the often abundant fruits. If you see seedlings coming up, remove them promptly.
Common Buckthorn is often confused with certain wild cherries and plums. The following illustration and descriptive notes should aid in distinguishing them.
Buckthorn twigs are tipped with a short, sharp thorn. The buds are slightly curved and pressed to the stem. The leaves are dark green with curved main veins, and hang on late into the fall without changing color. The berries are black and contain several seeds. The juice is greenish-black.
Cherries and Plums are closely related. Their twigs often emit an unpleasant odor when broken. The buds jut out from the twigs and are often clustered near the tip and/or bunched together on the sides. If thorns are present (on some plums), the thorns stick straight out from the twig like short branches. The leaves turn yellow in the fall and drop early. The berries can be red or black if pea-sized, blue yellow, red, or purple if larger. They all contain the familiar single, hard pit. The juice is red or purplish.