European (Common) Buckthorn (Rhamnus carthartica) is prevalent in riparian forests of the Meewasin Valley, in upland sites in Aspen, Chokecherry and Saskatoon patches and in shelterbelts of other non-native species such as Caragana. European Buckthorn is a deciduous small tree or shrub, native to Europe. It is found in urban parks, natural areas, and in backyards within Saskatoon and surrounding area. These trees or shrubs crowd and shade out native understory plants, eventually displacing native trees and shrubs. It has been found up to 60 km north, 20 km south and throughout the city of Saskatoon.
From 1998 to 2019, Meewasin, in partnership with the City of Saskatoon and other agencies, controlled approximately 1.73 million stems along the Meewasin Valley and within the City of Saskatoon.
Over the years, various control techniques have been tried and researched, with the most cost and time effective control method being a basal bark herbicide application. This technique involves directly applying a herbicide called Garlon RTU to the stem of the European Buckthorn at approximately 5 cm above the soil surface. This herbicide penetrates the bark of the stem and trans-locates down to the roots. The herbicide is oil based, therefore can be applied during colder temperatures (up to -15C).
The control efforts are conducted by City of Saskatoon, Parks Division and Meewasin Resource Management staff who are certified herbicide spray applicators with the Government of Saskatchewan.