Research on biological sprout control of Rosa rugosa with Chondrostereum purpureum begins in Espoo
The city of Espoo is participating in a study organized by the Natural Resources Institute Finland (Luke) that investigates the effectiveness of biological sprout control of Rosa rugosa, a harmful invasive alien species. Biological sprout control has been researched at the Natural Resource Institute (former Finnish Forest Research Institute) for 15 years.
Rosa rugosa grows, for example, on roadsides, the city’s green spaces, forests and beaches. There have been attempts at mechanically controlling the species by digging its undergrowth from the ground, but the problem has been that the plant can rapidly grow new undergrowth from parts of the plant left underground. As mechanical control is challenging, a biological method may prove useful, as the fungi can also spread to the plant’s undergrowth and decay it.
The biological sprout control method is based on the use of Chondrostereum purpureum, which is a species commonly found in Finland. This particular fungus can affectively decay broad-leaf trees, that have new damage, so that the trees’ sprouting is prevented.
The research takes place between 2024-2028. Parties participating in the study include Southwest Finland’s and Southeast Finland’s ELY Centres (Centre for Economic Development, Transport and the Environment) and the cities of Helsinki, Espoo, Lahti and Kotka. These parties have provided suitable growths of Rosa rugosa from their areas. These locations are situated on roadsides and beaches.
Growths in the study locations are treated in June. In Espoo, the treated growth is in beach areas around Haukilahti. In some areas, the treatment will be reapplied in spring 2026.
Rosa rugosa growth areas chosen for the study will be cut with a clearing saw and the cut surfaces will be sprayed with Chondrostereum purpureum mycelium, which is in an aqueous solution. Some Rosa rugosa bushes are only cut, no solution will be spread on them. The efficiency of biological sprout control in Rosa rugosa growths will be monitored annually in autumn between 2024-2028.