Rosa multiflora
(multiflora rose)

R. multiflora is a wild rose. It can form large, spreading, thorny thickets that can spread across grazing land and waste places, forming impenetrable barriers to both livestock and humans, and provide shelter for wildlife but also for pests such as rats. R. multiflora is a prolific seed producer. It is a declared noxious weed in several states in the USA, where it can reduce pastoral production as well as invading and damaging a number of habitats. R. multiflora occupies 45 million ha throughout the eastern USA, but outside North America it appears to be much less of a problem.

R. multiflora is native to East Asia. It has been introduced to Pakistan, South Africa, North America, Australia and New Zealand.

R. multiflora now occurs throughout eastern North America, from Newfoundland and Nova Scotia to northern Florida and west to Minnesota, Nebraska and Texas, as well as along the west coast from British Columbia to California (Munger, 2002). According to Underwood et al. (1996, cited in Van Dreische, 2002) R. multiflora occupies 45 million ha throughout the eastern USA. The plant frequently colonises roadsides, old fields, pastures, prairies, savannas, open woodlands, forest edges, and it can also invade dense forests where the canopy has been opened up.

The range of R. multiflora var. formosana falls within the overall range of variation for var. multiflora in China (eFloras, 2013). The two other varieties cultivated in China (var. alboplena, var. camea) do not occur spontaneously.

R. multiflora has been commonly used in many countries as a rootstock for other roses. In some regions it now occurs relatively widely, so its further spread within these countries is always possible. In New Zealand, as in Australia and formerly in North America, many wild R. multiflora plants are the result of stock spreading after the scion rose has died (Webb et al., 1988).

With its bird-dispersed seeds, R. multiflora is capable of establishing in gaps in established forests, although as these gaps are overtopped by mature trees R. multiflora is likely to be shaded out (Munger, 2002). 

In its native environment, R. multiflora occurs in thickets, scrub, slopes and riversides, from 300 to 2000 m above sea level (eFloras, 2013). It is seems particularly well-adapted to steep hillsides (Doll, 2006). R. multiflora tolerates a wide range of soil and environmental conditions, but is not found in standing water or in extremely dry areas (Munger, 2002). It is moderately winter hardy but can be killed by cold winters in northern USA (Doll, 2006).

R. multiflora frequently colonises roadsides and fence rows, stream banks, recreational land, old fields, pastures, prairies, savannas, open woodlands and forest edges, and it can also invade dense forests where the canopy has been opened up. It is often a component of early-successional communities on abandoned agricultural or pastoral lands (Munger, 2002)

In North America, where it is widely naturalised, it is most productive in sunny areas with well-drained soils. It is often a component of early-successional communities such as in abandoned agricultural and pastoral lands in the USA (Munger, 2002).

In Australia it is a minor environmental weed of roadsides, old settlements and creek lines (Herbiguide, 2013) and in New Zealand it mainly grows in and close to settlements on roadsides, in waste places and shrubberies around old gardens (Webb et al., 1988).

Genetics

2n=14 (Neumeyer, 2003).

Reproductive biology

R. multiflora canes root at the tip when canes touch the ground, and new stems can also arise from root sprouts and rhizomes (Eastman, 2003, cited in OGTR, 2009), although Doll (2006) claimed that this ‘is not a common phenomenon.’ On the other hand, Christen and Matlack (2009) reported that within-site spread is driven by vegetative propagation in close proximity to parent plants.

In North America, flowering occurs from late May to June. R. multiflora is pollinated is by insects. Van Dreische (2002) reported that the flowers produce ‘large amounts of golden, sweet-tasting pollen.’ The inflorescence has 25 to 100 flowers borne in terminal clusters (Doll, 2006). After pollination, single-seeded achenes with hard seed coats are formed within the fleshy fruits. The fruits are initially green but later become a very conspicuous bright red, when they are recognised as rose hips. Each hip contains 7-8 seeds and, if not eaten by birds, often persists on the parent plant, forming a dry leathery capsule.

Jesse et al. (2006) investigated insects that pollinated R. multiflora in Iowa, USA, and found the two most common pollinators were Syrphidae (hover flies) and Apis mellifera (honey bees), followed by other species of flies. Solitary bees and beetles were also seen visiting flowers, and a wide variety of other insects were caught on sticky cards placed on branches bearing flowers.

In southeastern USA robust bushes produce an average of 50 flower clusters on each cane. Each cane can theoretically produce 17,500 seeds each year; thus each plant has the potential to produce 500,000 seeds every year (Dreische et al., 2002).

Physiology and phenology

Fresh seeds removed from the hip show very low levels of germination, but leaching with activated charcoal or treatment with macerating enzymes improves germination (Yambe et al., 1995). Alternatively, R. multiflora seeds require about 6 weeks of moist chilling at 3^oC before they will germinate (Hartmann and Kester, 1975, cited in OGTR, 2009). Seeds made germinable by exposure to a mixture of enzymes had a germination rate of 60% after 2 minutes exposure to red light, an effect which could be reversed by exposure to far-red light (Yambe et al., 1995), which suggests that a phytochrome system is present in the seeds. Wyman (1940, cited in Eckardt and Martin, 2001) mentioned that scarification of the seeds by passage through the digestive systems of birds enhanced germination.

Longevity

Doll (2006) claimed that, unless killed by human or natural means, plant of R. multiflora live indefinitely, but added that there was no data on how long individual bushes might live. Several authors claim that the seeds can live for 20 years in the soil, but objective proof of this seems to be lacking (Doll, 2006).

Activity patterns

In the USA, R. multiflora flowers from late April through to June, depending on the location. Fruits develop by late summer and often persist until spring (Munger, 2002).

Associations

R. multiflora is often a component of early-successional communities on abandoned agricultural or pastoral lands. It is associated with very many other species of plants, depending on where it occurs. Munger (2002) presenteds a long list of communities or ecosystems in North America where R. multiflora may occur.

Environmental requirements

R. multiflora a grows best on deep, fertile, well-drained but moist uplands or bottom-lands; however, it  has wide edaphic limits, and that its growth is fair to good even on relatively adverse sites such as eroded claypans in central Missouri and southern Illinois, USA (Eckardt and Martin, 2001, citing Wyman, 1949 and Steavenson, 1946). The same author reported that growth was poorest where the topsoil has been removed entirely and the subsoil is an impervious drab plastic clay or where drought blow-sand is encountered. Fertiliser applications were only moderately useful in promoting growth on poor soils (Steavenson, 1946).

Hindal and Wong (1988) reviewed the natural enemies of R. multiflora in North America and elsewhere. Among the fungi attacking the species were Cylindrocladium scoparium and several species of Phragmidium. Bacterial diseases included crown gall (Agrobacterium tumefaciens) and fire blight (Erwinia amylovora). Several nematode species have also been recovered from R. multiflora.

Rose rosette virus has in the past caused serious losses of rose hybrids and some R. multiflora hedges in Nebraska, and has been observed causing serious losses to R. multiflora in Kansas, Arkansas and Missouri, USA. The symptoms include witch’s brooming, altered leaf and floral development and leaf colour reddening.

Of the many insects reported from cultivated roses, only the rose seed chalcid, Megastigmus aculeatus var. nigroflavus, has been reported to damage R. multiflora significantly.

Hindal and Wong (1988) surveyed pests and diseases on R. multiflora growing in West Virginia, USA. No diseases seemed to be having any major impact on the plants and, although they found many insects associated with the species, only five were thought to be damaging the plants: Popillia japonica (Japanese beetle), cicadas, totricid hip borers (Grapolita packerdi), raspberry cane borer (Oberea bimaculata) and the rose seed chalcid. The authors concluded that rose rosette virus (carried by the eriophyid mite Phyllocoptes fructiphilus) was a good option for use as a biocontrol agent, although some of the hip and cane borer insects and rose seed chalcids could also be considered. 

Environmental

• Agroforestry
• Boundary, barrier or support
• Erosion control or dune stabilization
• Land reclamation
• Shade and shelter
• Wildlife habitat

General

• Sociocultural value

In New Zealand many specimens are almost or completely thornless due to artificial selection, although some wild plants have prominent prickles (Webb et al., 1988). In contrast, in North America, Doll (2006) reported that the easiest way to distinguish R. multiflora from nearly all the wild roses is its large size and the fact that it is one of the ‘thorniest’ of roses.

The stipules at the base of the leaf petiole are feathery in nature and are characteristic of R. multiflora.

In North America there are three native roses that resemble R. multiflora: prairie rose (R. setigera Michx.), swamp rose (R. palustris Marsh.), and Arkansas rose (R. arkansana Porter.) (SE-EPPC, 2013). R. setigera is distinguished from R. multiflora by longer, trailing and arching stems, larger white flowers (2-3 cm) in a pyramidal inflorescence and smaller fruit. R. palustris is distinguished from R. multiflora by its shorter height (2 m) and solitary flowers, and R. arkansana has stems densely covered by slender, straight thorns and is much shorter overall, being rarely over 1 m.

R. multiflora var. cathayensis has pink flowers 40 mm in diameter, as opposed to the white flowers 15-20 mm in diameter of R. multiflora var. Multiflora (Herbiguide, 2013).

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Physical/mechanical control

Established plants can prove difficult to control and the vigorous root system can make mechanical removal of control by burning challenging. When clipped to a height of 7.5 cm every two weeks during the growing season, plants took two years to kill (Bryan and Mills, 1988). Even so, regular repeated mowing or cutting of individual plants, especially at the seedling stage, will eventually give effective control. Munger (2002) recommended 3-6 mowings or cuttings a year, repeated for 2-4 years. As with other woody species, painting the cut stems with herbicide can speed up the process.

Biological control

The rose rosette disease, a virus-like organism, has potential as an effective biocontrol agent for R. multiflora, although its use as a biological control agent has been opposed by the American Rose Society and by rosarians in general (Van Dreische et al., 2002). It has, however, been transmitted to target multiflora roses by grafting and by mite releases in Iowa and West Virginia, USA.

Van Dreische et al. (2002) claimed that rose rosette disease is ‘virtually certain’ to greatly reduce the density of R. multiflora, and that the reduced populations left afterwards ‘are likely to be infested by the seed chalcid at the same rate (90 to 95%) as plants in Korea and Japan.’

Chemical control

Munger (2002) lists a number of herbicides used for R. multiflora control, including glyphosate (as a cut-stem treatment), triclopyr (as a cut-stem or basal bark treatment), picloram, fosamine, dicamba and metsulfuron. Application of herbicide to cut stems can prevent resprouting and reduces damage to non-target plants. Some herbicides (triclopyr, picloram and metsulfuron) can be used as foliar sprays applied when fresh spring growth has started. Basal bark application of herbicide to the lower regions of the stem in winter can also be effective. Basal bark and cut-stem treatments are easier to apply when the plants are large with few main stems.

Derr (1989) compared the effectiveness of foliar treatments of metsulfuron and 2,4-D plus dicamba in April (spring) and August (autumn) applications in Virginia, USA. He also used spotgun treatments applying different rates of metsulfuron to the soil in May and August. Foliar-applied metsulfuron gave over 95% control with a spring application, but was less reliable when applied in autumn. 2,4-D plus dicamba also proved more reliable when applied in spring. Spotgun treatments proved slightly less effective than foliar sprays.

Control by utilization

In the same way as repeated mowing or slashing can reduce infestations, periodic grazing, especially of young seedlings, can be effective. Domestic sheep and especially goats will fed on leaves, new buds and new shoots. Goats have been used for effective control of a range of spiny and prickly plants in many parts of the world (Popay and Field, 1996), and Luginbuhl et al. (1999) have demonstrated that they are effective on R. multiflora: in four seasons severe infestations were virtually eliminated.

IPM

Perhaps the most important message about controlling R. multiflora is to eliminate the first one or two plants on a property or in an area, preferably before they mature and produce seed (Renz and Drewitz, 2008). Strongly competing ground cover of grass or other low-growing vegetation will help to suppress new seedlings, and fairly regular grazing with sheep or goats will also help to kill any newly emerging seedlings. Any plants that establish should be controlled with herbicide before they can fruit.

Lingenfelter and Curran (2013) suggested planting pasture species appropriate to the climate, soil and field conditions, using suitable fertilisers, mowing regularly and watching out for problem weeds and killing them early. Big, well-established R. multiflora bushes can be pulled out or removed with suitable machinery, but all roots should be removed and the area carefully monitored for any subsequent resprouts or new germination.

Munger (2002) often mentioned the lack of ecological information on R. multiflora: ‘the biology and ecology of multiflora rose are not well-studied. More research is needed to better understand its life-history and other biological traits, habitat requirements and limitations, and interactions with native North American flora and fauna.’

16/11/13 Original text by:

Ian Popay, consultant, New Zealand, with the support of Landcare Research.