Authors: members of the Global Invasive Species Team, The Nature Conservancy
- Chinese silvergrass is a tall, up to 12 ft. (3.7 m), densely-bunched grass that invades roadsides, forest edges, old fields, and other disturbed areas throughout the United States.
- The leaves are long (up to 18 in. [45 cm]), slender, and upright-to-arching with sharp tips and rough margins. The midribs are silvery in color.
- The terminal panicle is fan-shaped, long (2 ft. [0.6 m] in length), and silvery to pink in color. Flowering occurs in late summer.
- Each fertile lemma in the panicle bears an awn that is 8-10 mm long and is spirally twisted at its base. It can also spread through rhizomes.
- Ecological Threat
- Chinese silvergrass escapes from ornamental plantings and can form large clumps along disturbed areas, displacing native vegetation. The grass is also extremely flammable and increases fire risks of invaded areas. Chinese silvergrass is native to Asia and was introduced into the United States for ornamental purposes during the late 1800s.
Miscanthus sinensis is a popular horticultural bunch grass with many cultivars. Miscanthus sinensis ‘Giganteus’ is primarily grown for the production of bio-energy or paper pulp in Europe and Asia. The quick growing plant also has a use in preventing soil loss in agricultural fields when grown as a hedge. Other Miscanthus species are used for landscaping as well.
Miscanthus sinensis prefers full sun and moist, rich soil that drains well. Slight drought can be tolerated once plants are established. New shoots begin to grow from the ground in March or April. Plants tolerate cold climates but do not grow well in hot, humid southern climates. Horticulturists claim it can be grown in zones 5-9, i.e. it can tolerate winter temperatures as low as -26ºC (-15ºF), and can survive as far south as the Florida panhandle. It has been observed escaping along roadsides in North Carolina (Enloe 1999). Mutoh (1985) observed that M. sinensis populations grew in disturbed areas that had been burned or cut.
Miscanthus sinensis has a branched, subterranean rhizome system. It spreads rhizomatously, and pieces of rhizome 4 cm long can be used to propagate the plant (Nielsen 1987). Research to determine if plants bought from nurseries are self-seeding is occurring currently. Aficionados of bunch grasses feel this plant rarely or never produce seed, although some strains of Miscanthus sinensis seed easily. Replanting with desirable plants after the removal of M. sinensis should occur as Mutoh (1985) observed that Miscanthus invaded soil that had been disturbed by burning or cutting. On the whole, Miscanthus does not seem to pose as aggressive a threat as other invasive grasses.
The ability of M. sinensis to reshoot from pieces of rhizome makes control difficult. The whole underground rhizome system must be killed in order to prevent regrowth the next year. Digging out plants will probably result in resprouts and would need follow-up treatments. Similarly, discing and cutting methods may spread rhizome pieces into clean areas.
Miscanthus sinensis productivity is lessened with defoliation (Huggett 1997), but the effects of grazing, burning, and cutting in various combinations are not at all consistent. No single approach has yet been shown to be consistently effective, although the amount of Miscanthus present and its seed production can be reduced by using any of them. In Japan, a M. sinensis grassland tolerated being cut 1-5 times over the course of five months (Hayashi 1994). A study in Korea found that M. sinensis still dominated plots after cutting and was present in uncut burned areas (Che, 1997).
Meanwhile, in agricultural settings, weeding and grazing close to the ground provided control of M. sinensis. Weeding around the crown of planted trees (one-year-old Cryptomeria japonica and Chamaecyparis obtusa) was successful if M. sinensis was cut at a low height (Tange 1993). Miscanthus sinensis grazing in a Japanese conifer plantation provided significant control of weeds (Nogami 1993).
As with similar bunchgrasses and Pampas grass, the best control would probably be achieved by using a foliar application in the fall (2% Roundup® or 1% Fusilade®) or in the late spring (4% RoundUp® or 2% Fusilade®) (Enloe, personal communication; Drewitz, personal communication). Lower rates are required in the fall since translocation to the rhizome is occurring at that time. It is unknown how cutting prior to application would affect effectiveness during either season.
Che-S., W. Kim and S.H. Che. 1997. Comparison of plant communitystructures in cut and uncut areas at burned area of Mt. Gumo-san. Journal of Korean Forestry Society 86(4):509-520.
Drewitz, J. J. 1999, personal communication.
Enloe, S. F. 1999, personal communication.
Hayashi, I. 1994. Experimental community ecology in Miscanthus sinensis grassland - change of species composition according to mowing frequency. Japanese Journal of Ecology 44(2):161-170.
Huggett, D.A.J. 1997. The effect of timing and severity of artificial defoliations upon the yield of Miscanthus sinensis 'Giganteus'. Aspects of Applied Biology 49:129-136.
Kees, H., H. Raab and A. Penzkofer. 1994. Weed management in Chinese sedge (Miscanthus sinensis) - first experiences in Bavaria. Gesunde Pflanzen 46(4):139-143.
Kim, Y.J., G.J. Park, S.S. Choi, S.J. Hwang and W.B. Yook. 1995. Ecological studies on weeds in cultivated pasture. II. Effects of pasture management and utilization characteristics of weed development. Journal of Agricultural Science and Livestock 37(2):564-572.
Mutoh, N; Kimura, M; Oshima, Y; Iwaki, H. Species diversity and primary in Miscanthus sinensis grasslands: 1. Diversity in relation tostand structure and Botanical Magazine Tokyo, v.98, n.1050, 1985:159-170.
Nielsen, P N. Vegetative Propagation of Miscanthus sinensis Cultivar 'Giganteus'. Tidsskrift for Planteavl, v.91, n.4, 1987:361-368.
Nishiwaki, A., K. Sugawara and I. Ito. 1996. The effect of cattle grazing on seed production in Miscanthus sinensis Anderss. Grassland Science 42(1):47-51.
Nogami, K., Y. Muramoto and M. Nakagawa. 1993. Grazed plants by Wagyu cattle and weeding of Miscanthus sinensis by grazing in young Cryptomeria japonica and Chamaecyparis obtusa plantation. Bulletin of the Faculty of Agriculture, Miyazaki University 40(2):113-119.
Tange, T., M. Suzuki, H. Yagi, S. Sasaki and Y. Minamikata. 1993. Influence of the weeding method on the growth of planted trees. Journal of the Japanese Forestry Society 75(5):416-423.