Managing Invasive Buckthorn

Abstract

There are two types of invasive buckthorn in Minnesota: Common (European) buckthorn (Rhamnus cathartica) and glossy buckthorn (Frangula alnus). Both species were introduced to Minnesota as ornamental plants and have now spread widely across the state. They outcompete native plants, suppress growth of canopy tree seedlings, and reduce habitat quality for wildlife. Both species are listed as restricted noxious weeds in Minnesota (https://www.mda.state.mn.us/plants-insects/minnesota-noxious-weed-list) and both are ranked high on the Minnesota Invasive Terrestrial Plants and Pests Center’s (MITPPC) research priority list (https://mitppc.umn.edu/invasive-species-prioritization). Many landowners in Minnesota work to remove buckthorn from their property by hand-pulling, using removal tools, or treating with herbicide. But preventing buckthorn from coming back remains a challenge.

Removing buckthorn increases the availability of key resources like light and nutrients that enhance plant growth. Unfortunately, these resources are often quickly used by new buckthorn plants arising from seed or resprouting from cut stumps. As a result, buckthorn is particularly good at re-invading an area, and often rapidly returns after removal. Meanwhile, native plants are often slow to return because their seed banks have been depleted by buckthorn dominance.

In this toolkit: • Current and ongoing buckthorn management research at MITPPC that can help • How to identify glossy and common buckthorns • How to remove buckthorn • How to replant native vegetation to prevent future reinvasion