Buckthorn

Invasive species

Nature

Most of these invasive plant factsheets are created from the booklet Minnesota invasive non-native terrestrial plants, an identification guide for resource managers.

Check the additional resources and herbicides table for more information.


Buckthorn

Common buckthorn leaves
Buckthorn leafs out early and retain leaves late into the fall creating dense shade that helps it to out-compete many native plants.

Common buckthorn (Rhamnus cathartica) was first brought to Minnesota from Europe in the mid-1800s as a very popular hedging material. Shortly after its introduction here, it was found to be quite invasive in natural areas. The nursery industry stopped selling it in the 1930s, but many buckthorn hedges may still be found in older neighborhoods throughout Minnesota.

Glossy buckthorn (Frangula alnus), also from Europe, has been sold by the nursery trade in three different forms. The cultivar Columnaris has a narrow and tall form; the cultivars Aspenifolia and Ron Williams have narrow leaves that give them a fern-like texture. This buckthorn aggressively invades wetlands including acidic bogs, fens and sedge meadows.

Why is buckthorn such a problem?

  • Out-competes native plants for nutrients, light, and moisture
  • Degrades wildlife habitat
  • Threatens the future of forests, wetlands, prairies, and other natural habitats
  • Contributes to erosion by shading out other plants that grow on the forest floor
  • Serves as host to other pests, such as crown rust fungus and soybean aphid
  • Forms an impenetrable layer of vegetation
  • Lacks "natural controls" like insects or disease that would curb its growth

Regulations

European or common buckthorn and glossy or alder buckthorn are listed as Restricted noxious weeds in Minnesota. It is illegal to import, sell, or transport buckthorn in Minnesota.

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