Japanese rose – Rosa rugosa

Japanese rose is native to East Asia, i.a. the Korean Peninsula and northern parts of China and Japan. In the original range, it grows on sandy and gravelly seafronts by the Pacific Ocean. From there, it has been imported to other continents as an ornamental plant. To Europe, it was imported from Japan as early as in 1796, but only since 1845 it has become more common and has spread as a popular species in ornamental plantings. In Germany, Japanese rose became established in 1845, in Denmark in 1875, in Sweden in 1918, and in Norway in the 1940s.

Today, the species is a problematic garden escapee in several European countries. It reproduces from seeds and it also spreads vegetatively through rootstocks in its wide root system. It is mainly spread by the autumn migration of birds. Unlike other roses, japanese rose has very well adapted to the dispersal of seeds by water (hydrochory). Both rose hips and seeds float and thus can drift in water to new habitats.

In Finland, Japanese rose can be found as an ornamental plant in various plantings as well as an escapee on roadsides and in the environment, especially on the coastal areas, where it forms low, extensive stands. In the early 20th century, it began to spread from courtyards and gardens to the environment, first slowly and, after getting a foothold, ever faster. Most of its habitats are still located in built-up areas and areas of scattered settlement. It tolerates saltiness well and the mass plantings on roadsides have contributed to its spread. In the wild, the plant quickly found suitable habitat from sandy seafronts and gravelly areas of the archipelago, where it usually has spread with birds or water.

Japanese rose spreads uncontrollably on sandy beaches as well as on roadsides. It continues intensively to spread and so far its occurence extends as far as to the Kemi region, and there are observations of it in Lapland too.