Common Buckthorn, also known as European Buckthorn, is an invasive shrub throughout all of Ohio, the greater Midwest, and in fact quite a large portion of the Eastern United States. Its ability to colonize fencerows, fields, and neglected areas, coupled with its tough constitution and rapid growth rate, allow it to quickly produce copious amounts of black fruits on relatively young female shrubs. It is spread via bird consumption and subsequent dispersal to surrounding areas, much like Amur Honeysuckle (in fact, these two foreign shrubs often occupy the same niches, displacing native shrubs and trees). The most positive aspect of this large shrub or small tree is its glossy, dark green foliage, which is usually clean throughout the growing season (that is, no diseases or pests bother it) and the leaves usually hang on rather late into autumn. Its heartwood is bright orange, and its wood strongly resists rotting.
Common Buckthorn is named for the semi-thorny nature of its short twigs, which terminate in modified spines, rather than buds. The specific epithet refers to a cathartic drug that is extracted from the bark. Specimens found in the wild may reach 15 feet tall and 15 feet wide; those limbed up and thinned of smaller trunks at the base may grow to 25 feet tall by 20 feet wide. As a member of the Buckthorn Family, it is related to other Buckthorns, including two that are used in modern landscapes.
Potential Problems - Common Buckthorn is extremely invasive via the production, dispersal, and germination of its many seeds, which female shrubs start producing at a young age. In the first two years of its life, its black roots are shallow and fibrous, making them easy to pull up (and either throw away, or transplant). In addition, Common Buckthorn serves as the alternate host for a type of fungal rust (Puccinia coronata) that devastates oats and other cereal grains.
Common Buckthorn is highly invasive and should not be planted in Ohio.