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Home > Plants, Pests & Pest Control > Pest Management > Noxious & Invasive Weed Program > NWAC > Risk Assessments > Giant Miscanthus

Giant Miscanthus Risk Assessment

Common Name: Giant Miscanthus, Giant Silver Grass, Giant Chinese Silver Grass
Latin Name: Miscanthus x giganteus J. M. Greef & Deuter ex Hodk. & Renvoize (Syn. M. floridulus, M. japonicus)

Reviewer: James Calkins

Date: 09/12/2012
File #: MDARA00015MISGIG_1_18_2013

Giant miscanthus (Miscanthus x giganteus) is a tall (on average 8-12 feet, but can reach heights of 13-15 feet), perennial, rhizomatous, warm-season grass (Poaceae) that is native to Japan. It is a hybrid species between Miscanthus sinensis (Chinese silver grass) and Miscanthis sacchariflorus (Amur miscanthus). It is a triploid and sterile, producing no seed; plants rarely flower in Minnesota and spreads slowly by rhizomes. Giant miscanthus has low fertility requirements, performs well on poor soils, and has spurred considerable interest in Europe and the United States as a biomass crop that can be used for energy production through direct combustion and the production of ethanol and other biofuels. Giant miscanthus also has potential as a biochar feedstock and may have the potential to play a role in carbon sequestration.

Although giant miscanthus tolerates a wide variety of soils and is relatively drought tolerant once established, it performs best on moist, fertile soils in full sun. It makes a striking statement in the landscape and is not easily lodged by wind and snow. It is hardy to USDA Cold Hardiness Zone 4.

Final Results of Risk Assessment

Review Entity | Outcome

NWAC Listing Subcommittee: No Regulatory Action.
Comments: Not thought to be a threat in Minnesota at this time.

NWAC Full-group: No Regulation. Recorded to NWAC Database.

MDA Commissioner:


Box Question Answer Outcome (i.e., Go to box:?)
1 Is the plant species or genotype non-native? Yes; a naturally occurring hybrid between Miscanthus sinensis and M. sacchariflorus; both are native to Japan. Go to Box 3.
2 Does the plant species pose significant human or livestock concerns or has the potential to significantly harm agricultural production? No.  
2A Does the plant have toxic qualities that pose a significant risk to livestock, wildlife, or people? No.  
2B Does the plant cause significant financial losses associated with decreased yields, reduced quality, or increased production costs? No.  
3 Is the plant species, or a related species, documented as being a problem elsewhere? No. Go to Box 4.
4 Is the plant species’ life history & growth requirements are understood? Yes. Go to Box 6.
6 Does the plant species have the capacity to establish and survive in Minnesota? Yes; hardy to USDA Zone 4.  
6A Is the plant, or a close relative, currently established in Minnesota? Yes. Go to Box 7.
7 Does the plant species have the potential to reproduce and spread in Minnesota? Yes; only by vegetative means – a sterile triploid.  
7A Does the plant reproduce by asexual/vegetative means? Yes; rhizomes. Go to Box 7B.
7B Are the asexual propagules effectively dispersed to new areas? No. Go to Box 7C.
7C Does the plant produce large amounts of viable, cold-hardy seeds? No; sterile. Go to Box 7D.
7D If this species produces low numbers of viable seeds, does it have a high level of seed/seedling vigor or do the seeds remain viable for an extended period? No; sterile, no seeds produced. Go to Box 7E.
7E Is this species self-fertile? No; Miscanthus x giganteus is sterile and does not produce viable seed; all Miscanthus spp. are self-incompatible and require out-crossing to produce viable seeds. Go to Box 7G.
7F Are sexual propagules – viable seeds – effectively dispersed to new areas? No.  
7G Can the species hybridize with native species (or other introduced species) and produce viable seed and fertile offspring in the absence of human intervention? No. Go to Box 7H.
7H If the species is a woody (trees, shrubs, and woody vines) is the juvenile period less than or equal to 5 years for tree species or 3 years for shrubs and vines? No. The plant is not currently believed to be a risk –   No Regulatory Action.
7I Do natural controls exist, species native to Minnesota, that are documented to effectively prevent the spread of the plant in question? No.  
8 Does the plant species pose significant human or livestock concerns or has the potential to significantly harm agricultural production, native ecosystems, or managed landscapes? No.  
8A Does the plant have toxic qualities, or other detrimental qualities, that pose a significant risk to livestock, wildlife, or people? No.  
8B Does, or could, the plant cause significant financial losses associated with decreased yields, reduced crop quality, or increased production costs? No.  
8C Can the plant aggressively displace native species through competition (including allelopathic effects)? Yes.  
8D Can the plant hybridize with native species resulting in a modified gene pool and potentially negative impacts on native populations? No.  
8E Does the plant have the potential to change native ecosystems (adds a vegetative layer, affects ground or surface water levels, etc.)? Yes.  
8F Does the plant have the potential to introduce or harbor another pest or serve as an alternate host? No; apparently not; no specific information found.  
9 Does the plant species have clearly defined benefits that outweigh associated negative impacts? Yes; does have benefits.  
9A Is the plant currently being used or produced and/or sold in Minnesota or native to Minnesota? Yes; not commonly grown in Minnesota.  
9B Is the plant an introduced species and can its spread be effectively and easily prevented or controlled, or its negative impacts minimized through carefully designed and executed management practices? Yes.  
9C Is the plant native to Minnesota? No.  
9E Does the plant benefit Minnesota to a greater extent than the negative impacts identified at Box #8? Has significant potential as a biomass crop for energy production (direct combustion, cellulosic EtOH, gasification/syngas); 2X greater biomass production and 4X the EtOH production of corn; a risk assessment performed on Miscanthus x giganteus by Barney and DiTomaso (2008) recommended no regulation.  
10 Should the plant species be enforced as a noxious weed to prevent introduction &/or dispersal; designate as prohibited or restricted?    
10A Is the plant currently established in Minnesota? Yes.  
10C Can the plant be reliably eradicated (entire plant) or controlled (top growth only to prevent pollen dispersal and seed production as appropriate) on a statewide basis using existing practices and available resources? Yes; mowing and glyphosate.  


  1. Barney, J. and J. DiTomaso. 2008. Nonnative Species and Bioenergy: Are We Cultivating the Next Invader? BioScience 58(1): 64-70.
  2. Gordon, D.R., K.J. Tancig, D.A. Onderdonk, and C.A. Gantz. 2011. Assessing the Invasive Potential of Biofuel Species Proposed for Florida and the United States Using the Australian Weed Risk Assessment. Biomass and Bioenergy 35: 74-79.
  3. Jørgensen, U. 2011. Benefits Versus Risks of Growing Biofuel Crops: The Case of Miscanthus. Current Opinion in Environmental Sustainability 3: 24-30.
  4. University of Minnesota Extension. 2012. Miscanthus (Miscanthus x giganteus) for Biofuel Production.
  5. Matlaga, D.P., B. Schutte, and A.S. Davis. 2012. Age-Dependent Population Dynamics of the Bioenergy crop Miscanthus x giganteus in Illinois. Journal of Invasive Plant Science and Management. 5: 238-248.
  6. University of Minnesota. 2011. Miscanthus Ornamental & Invasive Grass. http://miscanthus.cfans.umn.edu
  7. USDA Natural Resources Conservation Service. 2011. Planting and Managing Giant Miscanthus as a Biomass Energy Crop. Technical Note No. 4.