Terrestrial invasive species


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, 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?


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.

More about buckthorn