Rosa rugosa Thunb. (Rugosa rose, Beach rose, Salt spray rose, Japanese rose, Turkestan rose). Rosaceae family.
Rugosa rose is native to East Asia from Russia (Okhotsk Sea region and the southern Kamchatka Peninsula) to northeastern China (Jilin, Liaoning, Shandong), and throughout Korea and Japan (Hokkaido and Hunshu).
Rosa rugosa is a woody perennial that begins as a small sprouting shrub and eventually forms dense prickly thickets 5-7 ft in height (Bruun, 2005). Its leaves are alternate, odd-pinnate with usually 5-9 leaflets ranging from 0.8-2 x 0.6-1.2 in., wrinkled, dark green, with serrated edges, smooth above while slightly pubescent and sticky underneath (Bruun, 2005). It has woody stems covered with thin, erect, sharp thorns of various sizes. The flowers are hermaphroditic, large (2.4-3.5 in. across), fragrant and range in color from dark pink or purple to white, depending on the cultivar (Bruun, 2005). The fruits are large as well (0.8-1.2 in across), and are glossy, red, fleshy hips that ripen in late summer to first frost in fall (Bruun, 2005).
- ECOLOGICAL THREAT:
Indigenous Species Reduction
- The shadowing effect of Rugosa rose can lead to a strong reduction of native species. It has the ability to form dense hedges. When the native plant life is displaced the animal species that depend on those native plants is also threatened.
Alteration of Physical Habitat
- Jensen (1958) notes that Rugosa rose plants were observed starting dune formation, thereby altering the physical habitat substantially.
- DISTRIBUTION IN THE USA:
Rosa rugosa is currently found in 19 states: throughout New England (Maine, Vermont, New Hampshire, Massachusetts, Connecticut and Rhode Island), New York, New Jersey, Michigan, Minnesota, Wisconsin, Illinois, Ohio, Pennsylvania, Virginia, West Virginia, Missouri and Washington (USDA, NRCS 2007).
- HABITAT IN THE USA:
Rugosa rose is usually found in dry coastal, sandy and gravely habitats, such as dune scrub, dune grassland communities and shingle beaches (Bruun, 2005). It is often found along roadsides and railways because it has a high salt tolerance and can withstand the constant winter salting of these areas. Rugosa rose can also be found inland as a garden escape, however it grows less vigorously in these regions (Bruun, 2005).
Rosa rugosa was initially introduced to the United States as a garden and landscape ornamental around 1845 (Rehder 1927). It was first reported as escaped from cultivation on Nantucket Island, Massachusetts in 1899 and 10 years later it was recorded throughout the island (Bicknell 1911).
- BIOLOGY & SPREAD:
Rugosa rose is an effective invader in part because of the several vectors that it utilizes to spread its seeds, of which seawater and birds are the most important (Bruun, 2005). In 1958, Jensen was able to demonstrate that entire hips and individual seeds could float for several weeks thus contributing to the ability of this species to traverse large distances. The hips were able to float for 40 weeks and when they disintegrated, individual seeds floated for an additional 4 weeks (Jensen, 1958). There were no consistent differences between salt water and fresh water for both the hips and individual seeds. In North America birds and to a lesser extent small rodents have contributed to local seed dispersal of Rugosa rose: many birds and rodents find the hips palatable and after ingesting them spread the seeds via their bodily excretions.
Rugosa rose has hermaphroditic flowers which are mainly cross-pollinated via insects, though self-pollination has been reported under experimental conditions. It also has the ability to grow vegetatively by rhizomes (Bruun, 2005). Anthropogenic human activity is also a factor in the dispersal of this species. Due to its fragrant smell, vibrantly colored flowers, immunity to many common rose diseases, ability to easily hybridize and low maintenance requirements, it has become a favorite among landscapers and florists. Although R. rugosa is considered invasive in 19 states, it and many of its hybrids can be easily purchased at local nurseries, florists and online (e.g. ebay) in the US.
- MANAGEMENT OPTIONS:
The techniques used for effective control of Rosa rugosa include digging, cutting, grazing and/or the use of herbicides (Wiedema, 2006). Any of these techniques need to be used consistently or they will increase the vigor of rugosa rose.
The most efficient method for removing the species has been to manually dig the plant up, making sure that the entire rhizome and root pieces have been removed (Wiedema, 2006 and Bruun, 2005). This method has been proven effective in both small and large areas, however it is less preferable in larger areas because it is very labor intensive (Widema, 2006).
Mechanical removal by any kind of caterpillar machine with a loading shovel can be effective for larger infestations (Wiedema, 2006). These machines essentially take an entire layer of sand away from the depth where the rhizomes are found, removing the shrubs and most of the rhizomes (Wiedema, 2006). Any stray pieces of rhizomes left can be treated manually afterwards.
Cutting the above ground flora may be a solution, but this approach needs long-term commitment, since repeated cutting is needed (Didriksen 1999). Cutting only once will ultimately rejuvenate the dense rose thickets.
Grazing as a control method is only relevant where Rosa rugosa enters an area that has previously been grazed. Grazing provokes vigorous re-growth by rhizomes, and very heavy grazing is necessary, often altering the plant community in an adverse direction. Goats are the only animals that seem to be able to graze Rosa rugosa enough to control it efficiently (Miljøministeriet et al. 2004).
If permitted by local conditions and legislation, herbicides (such as glysophates) can be an option. For small areas a paintbrush can be used, for large areas hand carried or tractor driven devices are needed. The herbicide should be applied specifically and only to Rosa rugosa by a trained and/or licensed individual.
Currently scientists are studying various biological control agents for this species. It has been shown that more insect and fungal species attack the Rugosa rose in its native range than in its introduced range (Bruun 2006).
All the mentioned measures have to be controlled and repeated or supplemented by other measures in the following years, with a continued management plan recommended (Weidema, 2006).
- ECONOMIC IMPACTS:
Rugosa rose has negative effects on outdoor recreation by hindering access to hiking trails and portions of the coastal beaches etc. However it also has some positive impacts: it can be used in preserves, perfumes and personal care products, and extracts from the hips are used to produce tea, and vitamin extracts.
Universityof Massachusetts , Boston . Boston, MA
Bicknell, E.P.1911.The ferns and flowering plants of Nantucket, VIII.Bulletin of the Torrey Botanical Club, 38.447-460.
Bruun, H.H.2005.Biological Flora of the British Isles.No.239.Rosa Rugosa Thunb. ex Murray.J.Ecol.93:441-470.
Brunn,H.H.2006.Prospects for biocontrol of invasive Rosa rugosa.Biocontrol 51:141-181
Rehder, A.1927.Manual of Cultivated Trees and Shrubs Hardy in North America. MacMillan Co.,New York, NY, USA.
Rehder, A.1949.Manual of Cultivated Trees and Shrubs Hardy in the Cooler Temperate Regions of the Northern Hemisphere.Arnold Arboretum.Jamica Plain, MA, USA.
Swank, W.G.1944.Germination of seeds after ingestion by Ring-necked Pheasents.J. of Wildlife Management.8:223-231.
USDA, NRCS. 2007. The PLANTS Database (http://plants.usda.gov, 05/16/2007).National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Weidema, I.2006.NOBANIS – Invasive Alien Species Fact Sheet –Rosa rugosa: Online Database of the North European and Baltic Network on Invasive Alien Species (http://www.nobanis.org, 04/05/2007)