There are a wide variety of non-native invasive plant species that have taken hold in Madison County. These plants cause harm to the environment, as well as potential harm to human, animal, and plant health in the preexisting environment. Some of these damages can be caused by overtaking beneficial native plants in the ecosystem, act as vectors for diseases and other invasive species, such as invasive insects, and are unhealthy or potentially toxic to native animals. In this series, we will discuss identification and control of these prevalent invasive plants. 

Identifying Miscanthus Sinensis

Miscanthus sinensis has a variety of common names that it is known by, including Chinese Silvergrass, Maiden Grass, Japanese Silvergrass, Eulalia, and—particularly in the region of Western North Carolina—Pampas Grass. This invasive species originated in Asia, and was brought into the United States for use as an ornamental grass, and can still be purchased for this purpose. Miscanthus has spread throughout the Southeastern United States, and is commonly spotted along roadsides and in areas with disturbed soils. 

is a bunchgrass, meaning that it is a type of grass that grows in clumps of erect stems that can grow to be up to twelve feet tall. These bunches tend to pack together densely in infested areas, with stems that are cane-like and sprout long, thin and hairless blades that stand upright or arching in green or variegated (or horizontally striped) color. The flowering seed heads of this plant emerge through the summer and fall in fan-shaped spikelets that grow vertically. The spikelet flowers create a fluffy appearance, which usually appear in a white, silver, or slightly pinkish color. 

Micanthus can grow in a wide variety of habitats, but prefers full sun areas with most, well-drained soil. It is intolerant of shade, but it can still spread into sparsely forested areas, and has the ability to form heavy infestations when reaching disturbed sites. It is a drought tolerant, wind tolerant, and deer resistant pest that often creates a monoculture in the areas where it has taken over.

How it Spreads

This invasive species is extremely prolific, spreading itself through strong root systems created by underground stems known as rhizomes. These rhizomal root systems can cause structural damage to the foundation of homes, walls, and roads while allowing Miscanthus to grow in dense patches with rapid growth. The small spikelet flowers contain seeds that can be spread with wind dispersion, when consumed by animals, and even carried on vehicles from one place to another. Due to the ability that Miscanthus has to spread quickly in disturbed areas, and the presence of rhizomes, this invasive species is difficult to control. Miscanthus spreads so prolifically that it can quickly create a monoculture environment, stamping out the growth of other, more beneficial grasses and other plants, like native grasses and those chosen for pasture forages.

Controlling Miscanthus Sinensis

Miscanthus is a difficult invasive species to control, thanks to its ability to resprout from any rhizomes that may be remaining in the soil. To gain successful control over this invasive species, the entire rhizomal root system must be killed to prevent regrowth. Manual or physical methods of control are generally ineffective for trying to contain the spread of Miscanthus. Digging out plants often causes resprouts from the rhizomes remaining behind in the soil, which would require further treatment to fully remove the plant. Cutting or disking the infestation risks spreading seeds and rhizomes into areas that are not currently infested, causing new spread. It is very important to note that burning is not an effective method of controlling Miscanthus. It is highly flammable, and creates a major fire hazard in areas with heavy infestation. Attempts to burn this invasive species often lead to a loss of control of the flames, and in turn wildfires. 

Chemical control has been shown to be effective in controlling and removing Miscanthus. The NC Forest Service has seen effective control of this invasive species with the use of a 2 to 3 percent solution of glyphosate mixed with 0.5 percent of a non-ionic surfactant, which helps the herbicide stick to the plants for a more effective dose. Be sure to apply the herbicide treatment either in the early spring, when regrowth stands about 12-18 inches tall, or wait until late summer before the plant sets seed. Be sure that, when using any pesticide, you use it according to the label directions. The label is the law!

If you have any other questions about identifying or controlling Miscanthus, please contact the Madison County Cooperative Extension Center at peyton_duckett@ncsu.edu, or (828) 649-2411.

Citations

NC Forest Service, & NC Department of Transportation. (2010, March). Invasive Species Leaflet. North Carolina Dept. of Agriculture and Consumer Services: NC Forest Service Division. https://www.ncagr.gov/divisions/nc-forest-service/is05/download?attachment 

NC State Extension. (n.d.). Miscanthus sinensis. North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/miscanthus-sinensis/ 

USDA Forest Service, Forest Health Staff. (2006, January 24). Chinese Silvergrass. Weed of the Week. https://www.invasive.org/weedcd/pdfs/wow/chinese-silvergrass.pdf