! NOTE: Recent research out of University of Minnesota – Minnesota Invasive Plants and Pests Center indicates that Buckthorn seeds may have short-term soil bank viability ~2-3 years. (Schuster et al. 2023) Check out the resources at the bottom of this page for more.
Common Buckthorn
Common buckthorn (Rhamnus cathartica) is a woody shrub that can be found in any disturbed or undisturbed area including old fields, along roadsides, woodlots, and pastures. Common buckthorns can be up to 25 feet tall and is deciduous. Leaves are slightly toothed, dark green, and oval shaped. In the spring it sprouts yellow flowers in small clusters at the base of leaves. Berries are similar to those on glossy buckthorns, they are small and ripen to a dark purple color and appear in the fall. Twigs may have sharp thorns on the tip and there is a distinctive orange inner bark color.
Glossy Buckthorn
Glossy buckthorn (Rhamnus frangula) is a woody shrub that is often found in wetlands, along fence rows, open woods, and along roadsides. Glossy buckthorns can either be the size of a large shrub or a small tree and are typically no larger than 18 feet. They have simple alternate leaves, with no teeth, and are shiny. White flowers bloom between May and September and small dark purple berries are visible from June to September. They have a distinctive orange inner bark.
Environmental Effects
Seeds are distributed through birds and wildlife. Both glossy and common buckthorn can form dense thickets that can prevent native species from growing underneath them. Which ultimately harms the native plant diversity present. This can also reduce the food availability to wildlife that depend on berries throughout the year.
Treatment
There are multiple treatment options for both common and glossy buckthorns. These include both chemical and non-chemical options.
NON-CHEMICAL CONTROL METHODS:
- Hand-pulling seedlings: if there are only small seedlings present, they can be hand pulled. They should be placed in an area that they will be unable to resprout and dry out. Ideally, should be bagged and thrown out.
- Mowing: large shrubs can be forestry mowed while small seedlings can be mowed with a lawn mower. Unless the stumps are treated with herbicide, they will resprout. Mowing can help reduce the large shrubs and re-open areas. It can also make chemical control easier.
CHEMICAL CONTROL METHODS:
- Foliar spraying: herbicide is sprayed directly onto the foliage of the shrub. This is most common for small to medium size shrubs. Plants should be sprayed in the summer after spring sap flow has begun. Note: herbicide sprayed onto nearby plants can cause them to die.
- Cut-stump treatment: herbicide is applied to the outer ring of the cut stump. It must be applied within a few minutes of the cut to be effective. Note: this should not be done in the spring as the plant will push the herbicide upwards and out of the plant completely.
- Basal bark: herbicide is applied with an oil carrier to the entire circumference of the lower 18 inches of the trunk. This method should only be used on stems that are less than 6 inches in diameter. Note: this should not be done in the spring or when there is snow or water present.