Glossy buckthorn (Frangula alnus) tolerates a wide variety of conditions but thrives best in wet or moist soils and is therefore found in wetlands, bogs, river and streambank habitats, and wet meadows. However, it can also grow in drier habitats such as forests, fields, roadsides, and disturbed areas. In Vermont, glossy buckthorn occurs in all counties, but is most common in Rutland, Windsor, Chittenden, Caledonia, and Essex counties.
Glossy buckthorn is a large shrub that typically grows to heights around 20 ft. The outer bark is grayish brown with white horizontal lines called lenticels and the inner bark is orange or yellow. Leaves are dark green and shiny, oval, alternate, and have untoothed edges and eight to nine pairs of veins. Glossy buckthorn has small, pale green or yellow flowers with five petals that emerge in clusters during the spring. The fruits are fleshy berries that ripen from green to red to a dark purple color in late summer.
Glossy buckthorn gains an advantage over native vegetation because it leafs out earlier and retains leaves later, which lengthens its growing season. This advantage allows buckthorn to outcompete native plants and inhibit forest regeneration. Glossy buckthorn is also a prolific seed producer and dispersal is aided by the birds and small mammals that readily eat the fruit. The fruit contains a natural laxative, which further aids in dispersal and also prevents the animals that feed on the fruit from absorbing beneficial sugars. It is also a host to the alfalfa mosaic virus and the crown rust fungi, which impact agricultural crops.
Control and Prevention
Smaller populations of glossy buckthorn can be controlled mechanically by pulling or cutting. Buckthorn plants can be pulled by hand or using a weed wrench for larger shrubs whenever the ground is soft. Plants can be cut throughout the year and frequent cutting, or cutting followed by wrapping stumps in burlap or thick plastic, helps reduce plant vigor and spread.
Chemical treatment is usually most effective in controlling glossy buckthorn infestations. Herbicide can be applied to cut stumps or sprayed on leaves during the fall. For large infestations or when buckthorn populations are near sensitive areas such as waterbodies and wetlands, contact a professional for chemical application.
To prevent the spread of glossy buckthorn, early detection and prompt removal of plants is essential. Removing plants before fruit is produced is important since buckthorn is so prolific. When pulling smaller plants, make sure to remove the entire root system and hang it from a branch to prevent re-rooting. It is also important to minimize soil disturbance when removing plants as disturbed soils provide more opportunities for establishment of new buckthorn infestations. If the fruit is already present when pulling or cutting plants, bag the fruit and dispose of it in a landfill.
Glossy buckthorn is on the Vermont Noxious Weed Quarantine list and so is illegal to purchase, plant, or transport it in the state.
Native Plant Sources
Check out Native Plant Sources for places to purchase plants native to Vermont.