Nathan Johnson, Director of Public Lands, May 23, 2018
Glossy buckthorn is one of the worst NNIS (non-native invasive species) in central Ohio and the Midwest. It aggressively invades and dominates native fields, forests, wetlands, and disturbed areas. Hailing from Europe, North Africa, and Central Asia, this shrub grows in dense thickets that shade out natives. Originally introduced as ornamental and wildlife plantings, Glossy Buckthorn quickly escaped its intended locales.
Glossy buckthorn is shade tolerant and thrives in forest edges and understories. It loves wet areas, but does well on a range of sites. Like many other NNIS, it competes well against natives by leafing out earlier in the spring and dropping leaves later in the fall. The plant fruits and seeds prolifically, and birds spread the berries over long distances. Glossy buckthorn is a seed banker, and seed can remain viable on the ground for up to five years. When the shrub is cut, stems sprout rapidly from the stump and can even fruit in their first year.
This invasive appears as either a multi-stemmed shrub or small tree. It can grow up to 20 feet tall, but is often in the 4 to 8 foot range. The leaves of glossy buckthorn are distinct — shiny, oval-shaped, smooth edged, and with prominent veins. The bark is gray-brown and covered in numerous white spots called “lenticels.” The small, white flowers are inconspicuous, but the berries tend to be a good give-away. The pea-sized berries each contain multiple seeds. They ripen from green to red to dark purple and black from July through September. Commonly, berries occurring on the same branch will be in various stages of ripeness (green through black). The berries are considered mildly toxic, and have a pronounced laxative effect.
Focus first on removing any plants that have berries. You may be able to hand-pull or dig up small specimens. Chemical control is recommended for all but the lightest infestations, as this species sprouts readily from the stump. Winter, late summer, or fall are the best seasons for control. Cut plants near the base and immediately spot treat the stump with an appropriate herbicide, such as (25%) glyphosate. Spring herbicide application may prove ineffective, because sap will be flowing upwards from the roots (which may prevent chemical penetration).