Bill Johnson, James Miller (inset)

Multiflora Rose

Rosa multiflora Thunb. ex Murr.
Rose family (Rosaceae)

Origin: Japan, Korea and Eastern China

Background
Multiflora rose was introduced to the eastern United States in 1866 as rootstock for ornamental roses. Beginning in the 1930s, the U.S. Soil Conservation Service promoted it for use in erosion control and as “living fences” to confine livestock. State conservation departments recommended multiflora rose as cover for wildlife. More recently, it has been planted in highway median strips to serve as crash barriers and reduce automobile headlight glare. Its tenacious growth habit was eventually recognized as a problem on pastures and unplowed lands, where it disrupted cattle grazing, and, more recently, as a pest of natural ecosystems. It is designated a noxious weed in several states, including Iowa, Ohio, New Jersey, Pennsylvania and West Virginia.

Distribution and Habitat
Multiflora rose occurs throughout the eastern half of the United States and in Washington and Oregon. It tolerates a wide range of soil, moisture and light conditions and is able to invade fields, forests, prairies, some wetlands and many other habitats.

Ecological Threat
Multiflora rose grows aggressively and produces large numbers of fruits (hips) that are eaten and dispersed by a variety of birds. Dense thickets of multiflora rose exclude most native shrubs and herbs from establishing and may be detrimental to nesting of native birds.

Description and Biology

• Plant: multi-stemmed shrub, sometimes climbing vine, with arching stems and recurved thorns.
• Leaves: divided into five to eleven sharply toothed leaflets; leaf stalks with fringed stipules (paired wing-like structures).
• Flowers, fruits and seeds: clusters of showy, fragrant, white to pinkish, 1 in. wide flowers appear during May; small bright red fruits, or rose hips, develop during the summer and remain on the plant through the winter.
• Spreads: reproduces by seed and by forming new plants from the tips of arching canes that can root where they contact the ground. An average plant produces an estimated one million seeds per year, which remain viable in the soil for up to 20 years.
• Look-alikes: pasture rose (Rosa carolina); swamp rose (Rosa palustris); Allegheny blackberry (Rubus allegheniensis); flowering raspberry (Rubus odoratus). Only multiflora rose has the combination of upright arching stems and fringed stipules.

Prevention and Control
Do not plant multiflora rose. Effective control of multiflora is possible using chemical, manual, or mechanical means or, preferably, a combination. Frequent, repeated cutting or mowing at the rate of three to six times per growing season, for two to four years, has been shown to be very effective. In high-quality natural communities, cutting of individual plants may be preferable to minimize habitat disturbance. Because of the long-lived stores of seed in the soil, follow-up treatments are necessary. Application of a systemic glyphosate-based herbicide to freshly cut stems, to regrowth, or to foliage is very effective, especially if done late in the growing season (see Control Options). Two naturally-occurring controls affect multiflora rose to some extent. A native virus (rose-rosette disease) spread by a tiny native mite impedes stem growth and a non-native seed-infesting wasp, the European rose chalcid, causes damage to the seeds.