I have seen and been part of a lot of Buckthorn (Rhamnus cathartica) removal efforts, and while initially hopeful, often there is a inevitable return of the non-native to once again take over the forest understory in short time. What if there were strategies, without herbicides or biocontrols to reduce or prevent the likeliness of Buckthorn’s recolonization?
Mike J. Schuster from the Department of Forest Resources at the University of Minnesota recently co-authored a paper looking into native phenological competitors to Buckthorn which can be planted after Buckthorn removal to help keep R. cathartica out. Luckily for me, one of the suggestions was a (fairly simple) practice I have been learning about and working on for the past 5 years! Plant more Elderberry! Sambucus canadensis and perhaps even more so S. racemosa can help block out the light essential to early Buckthorn growth. By planting these two shrubs , who have similar phenological timelines to the Buckthorn, we can help restore native biodiversity in forests experiencing Buckthorn invasions.