Regulations (pertaining to the Great Lakes region) In Wisconsin, Microstegium vimineum is listed as a prohibited species under Wis. Admin. Code § NR 40, making it illegal to possess or transport within the state. In Ohio, it is classified as a restricted invasive plant under Ohio Admin. Code § 901:5-30-01 prohibiting its sale, propagation, distribution, import, or intentional dissemination. In New York, M. vimineum is prohibited and cannot be knowingly possessed, sold, imported, purchased, introduced, or propagated under 6 NYCRR Part 575. Indiana added M. vimineum to its Prohibited Invasive Terrestrial Plant list (312 IAC 18-3-25) on 4/18/2020, banning its sale, gift, barter, exchange, distribution, transport, and introduction. As of 2017, Pennsylvania lists M. vimineum as a “Rank 1” invasive plant, but legislation only covers species defined as “Noxious Weeds”. Explicit regulations are not defined for Microstegium vimineum in Michigan, Minnesota, Illinois, or Ontario.
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
Pathogenic fungi in the Bipolaris species, including Bipolaris zeicola (Kleczeweski and Flory 2010) and Bipolaris Mv. (Kleczeweski et al. 2012), can cause leaf blight disease in many plants, including Microstegium vimineum. Infection results in lesions on the foliage and stem of M. vimineum and reduced seed head production, wilting, and occasional plant death (Kleczeweski and Flory 2010). Due to the destructive effects Bipolaris fungi can have, it has been suggested as a potential bioherbicide for invasive species such as M. vimineum. However, its application is highly impractical because Bipolaris can infect and harm a wide range of grasses and plants that co-occur with M. vimineum (Flory et al. 2011; Kleczeweski et al. 2012).
Physical
Mowing and hand-pulling can be effective methods of controlling small infestations and retaining native species. Both methods are best employed in summer and early fall (June-September) when plants are tall, but prior to seed set (Judge et al. 2008; Flory and Lewis 2009; Ward and Mervosh 2012; Shelton 2012). M. vimineum can regenerate from its seed bank for approximately 5 years after removal, thus physical control must be implemented every year until the seed bank is depleted (Tu 2000; Czarapata 2005; Flory 2010). Flooding continuously for 3 months can also kill the plants, however, it may not destroy soil-stored seed (Tu 2000).
Prescribed fire can be used to clear M. vimineum leaf litter and biomass, however, caution should be taken because future recruitment and M. vimineum biomass were greater in burned vs. unburned sites as it thrives in disturbed landscapes (Glasgow and Matlack 2007; Emery et al. 2013; Wagner and Fraterigio 2015). Alternatively, directly burning the plant stalks with propane torches is an effective treatment method but must be repeated annually (Ward and Mervosh 2012).
Forest management regimes can also be used to discourage M. vimineum colonization. In northeastern US deciduous forests, M. vimineum invasion was reduced by keeping canopy openings below 15%, excluding deer, and seeding the understory with native species (Heubner et al. 2018).
Chemical
A wide range of herbicides can be used to control Microstegium vimineum at a variety of timings and doses (listed as kilograms of active ingredient per hectare), in particular, pre- and post-emergence. The application of grass specific post emergent herbicides (e.g. clethodim, sethoxydim, pendimethalin, fenoxaprop-P , fluazifop-P, imazapic, pendimethalin, and fenoxaprop-p-ethyl) are the most effective herbicide at controlling M. vimineum and are best applied annually or bi-annually using a backpack sprayer to limit the unintended application to non-target plants. Broad spectrum foliar herbicides (e.g. glufosinate and glyphosphate) are nonspecific and kill native and non-target woody plants and can reduce species richness. If used, these chemicals should be applied shortly after germination (Flessner et al. 2019).
Herbicide application post-emergence can result in various control effects on M. vimineum, including reduced plant density and size, reduced seed head and seed production, and preventing emergence the year following treatment. M. vimineum density and size in a deciduous forest was reduced by at least 87% eight weeks after treatment using clethodim (0.1 kg a.i./ha), fenoxaprop-P (0.1 kg a.i./ha ), fluazifop-P (0.3 kg a.i./ha), sethoxydim (0.5 kg a.i./ha), or glufosinate (1.1 kg a.i./ha), but annual applications are needed to maintain control (Judge et al. 2005a;b). Following herbicide application in late July for two consecutive years, M. vimineum cover and seed head production was reduced to below 5% (untreated control 90%) at the end of the growing season and emergence was prevented a year after the second application using imazapic (0.140 kg a.i./ha), pendimethalin (3.36 kg a.i./ha) plus pelargonic acid (11.8 kg a.i./ha), fenoxaprop-p-ethyl (0.045-0.180 kg a.i./ha), glufosinate (0.14 -0.56 kg a.i./ha), 5% vinegar, or glyphosate (0.14-0.56 kg a.i./ha) (Ward and Mervosh 2012). Judge et al. 2005b, 2008 also found post-emergence glyphosate (2.2 kg a.i./ha) to be 100% effective at controlling M. vimineum. Fluazifop-P, when used at 0.21 kg a.i./ha post-emergence, effectively controlled and removed. Yearly re-application of any herbicide is recommended for maximum control of M. vimineum.
Cool-season forage grass approved aminopyralid (0.05 kg a.i./ha) or aminopyralid (0.05 kg a.i./ha) plus metsulfuron (0.001 kg a.i./ha) visually reduced M. vimineum by 70-90% 12 weeks after treatment (Flessner et al. 2019). The grass specific herbicide, sethoxydim, applied in July reduced M. vimineum cover from 80% to 20% by the end of the growing season but reapplication every year is required for continued control (Frey and Schmidt 2015).
See also:
Midwest Invasive Plant Network Invasive Plant Control Database