Common Buckthorn
Rhamnus cathartica · Deciduous, Invasive Broadleaf
Plant Family
Rhamnaceae
Tree Category
Invasive Shrub/Small Tree
Variety / Cultivar
None (Wild type)
Hardiness Zones
USDA Zones 3-8; highly adaptable to cold climates and varied urban conditions.
About This Tree
A large, multi-stemmed shrub or small tree reaching up to 25 feet. Known for its dense, thorny crown and tendency to form impenetrable thickets that shade out native understory vegetation. Growth is rapid and extremely opportunistic.
Leaf Characteristics
Simple, oval-shaped leaves, 1 to 2.5 inches long. They feature distinctive arcuate venation (veins curve toward the tip), finely serrated margins, and a mostly opposite or sub-opposite arrangement. Color is a dark, glossy green.
Bark Characteristics
Young bark is smooth and brown with prominent horizontal lenticels (white spots/streaks); mature bark becomes gray-black, rough, and scaly. Inner bark is notably bright orange.
Growing Information
Origin Region
Native to Europe, Northwest Asia, and North Africa; naturalized and invasive in North America
Growing Season
Leaves out early in spring, flowers in late spring (May-June), fruits ripen in late summer/fall, and holds leaves late into autumn
Sunlight & Water Needs
Highly adaptable; performs best in Full Sun to Partial Shade but is extremely shade-tolerant. Prefers moist soils but is highly drought-resistant once established.
Mature Size
Height: 20-25 feet; Spread: 10-20 feet; Growth Rate: Fast; Lifespan: Relatively short to moderate, but reproduces prolifically via seed.
Special Characteristics
Highly invasive; features terminal thorns at the ends of twigs. Berries contain anthraquinones which have a strong laxative effect on animals. Known to alter soil nitrogen levels to favor its own growth.
Wildlife & Ecology
Provides food (black drupe-like berries) for birds, which facilitates the spread of seeds. However, it is an ecological threat as it outcompetes native plants and serves as an overwintering host for the soybean aphid.