Common Buckthorn

Rhamnus cathartica

common buckthorn foliage
 Image credit: WIGL

Characteristics

Common buckthorn, a woody shrub/small tree in the Rhamnaceae family, is an understory invasive that produces large amounts of seeds and out-competes many native species. It’s also both sun and shade tolerant and can live in many different soil, moisture, and habitat conditions. Identifying features include:

  • dark-green, oval leaves with a toothed margin and veins that bend towards the tip
  • stems are brown, turning gray with age and covered in very prominent lenticels
  • females produce numerous black, round, bird dispersed drupes that are persistent through winter
  • small, green-yellow flowers, clustered, with four petals

Note: This plant can be confused with native cherries like pin cherry and choke cherry. Note that cherries will have two black spots on the leaf petiole (stem) and buckthorn will not.

For more information visit WiGL and MISIN.

 

KISMA Management Practices

Buckthorn is a highly aggressive species that produces copious amounts of seeds and saplings, and is able to take over an understory relatively fast. Here at KISMA, buckthorn is another major invasive species that we have at multiple sites. It’s important to revisit sites as buckthorn seeds are viable in the ground for multiple years and it’s important to remove all seedlings. KISMA prioritizes removal of seed trees and satellite populations first, to prevent further spread of buckthorn. 

  1. hand-pull small seedlings and saplings
  2. for stems to large to hand-pull, use a weed wrench to loosen the roots. After roots are loosened the tree should be easy to remove with hand pulling
  3. if the tree still cannot be removed with the weed wrench, cut the tree a few inches above the ground and securely cover with a thick trash bag, using zip-ties, to help prevent stump sprout regeneration and kill the root mass

Note: It's very important to remove seeds and seed bearing trees first, as this is the main reproduction strategy of buckthorn.

 

Native Alternatives

Great native alternatives to common buckthorn would be the native cherries like pin cherry (Prunus pensylvanica) and choke cherry (Prunus virginiana). Serviceberry (Amelanchier sp.) is also a great alternative providing a well needed food source to native wildlife. Other species like highbush cranberry (Viburnum trilobum) and other native shrub species are great as well.

common buckthorn leaves

(image credit: Sigrid Resh) oval-shaped leaves and mature fruit of common buckthorn

common buckthorn in the winter

(image credit: KISMA) drupes persist on branches through the winter

common buckthorn drupes

(image credit: Sigrid Resh) black round drupes on female tree

plastic bag to smother cut stumps

(image credit: Sigrid Resh) securely fastened plastic bag used to smother buckthorn stump sprouts after cutting

Sources

"Common buckthorn (Rhamnus cathartica)." MISIN, 2020.

"Rhamnus cathartica." Honey Plants.

"Northwest Michigan Invasive Species Network (NWISN)".

"Woody Invasives of the Great Lakes Collaborative (WIGL)".