Amur silver grass (Miscanthus sacchariflorus)

Amur maple leaves are longer than they are wide.

 
 

Amur silvergrass is an ornamental grass that can spread vegetatively through horizontal stems growing below the soil surface to form dense patches that crowd out other species.

Description

Appearance

Amur silvergrass is a perennial warm season grass that grows 6 – 8 feet tall. It is very showy and vigorous and forms dense mats.

Leaves and stem

Amur silvergrass leaves are arching, with a distinct whitish line down the center. They are less than 1 inch wide. There is a hairy fringe where the leaf meets the stem.

Flowers

The flowers are silky and plume-like in the fall. Amur silvergrass flowers resemble corn tassels but are more dense and arch to one side of the stalk.

Seeds and reproductive structures

Amur silvergrass is thought to produce little seed in Minnesota. It is believed that most Amur silvergrass patches are the result of vegetative spread by underground stems called rhizomes or from pieces of the roots or rhizomes being spread when soil is moved.

Roots and roots

The grass reproduces vegetatively through horizontal stems growing below the soil surface, called rhizomes, forming roots and producing new plants, eventually forming a dense mat.

Biology

Amur silvergrass is a perennial grass. It has been planted in Minnesota as an ornamental species. It is thought to produce few seeds in Minnesota and that most spread is due to vegetative spread by rhizomes. 

Origin and spread

Amur silvergrass is native to Asia. It was introduced to the United States as an ornamental plant. It is assumed that most patches are the result of spread from places where it was purposefully planted.
Refer to EDDMapS distribution maps for current distribution.

Don't be fooled by these look-alikes

  • Chinese silvergrass, Miscanthus sinensis (non-native) – Chinese silvergrass has awns (small hair-like bristles) on its florets while Amur silvergrass does not. See the University of Minnesota side by side comparison for all differences between the two species.
  • Reed canarygrass, Phalaris arundinacea (non-native) and its cultivars – Reed canary seed heads are more compact and less feathery-looking than Amur silvergrass.
  • Non-native subspecies of Phragmites, Phragmites australis subsp. australis (non-native) and the native subspecies of Phragmites, Phragmites australis subsp. americanus (native) – Minnesota has both a native and a non-native subspecies of Phragmites. Phragmites leaves do not have the white line down the center or the hairy fringe where the leaves meet the stem as Amur silvergrass does.
  • There are a number of native grasses that have showy seed heads. See the "Native Substitutes" section below to view some of those species.
 
Regulatory Classification

Amur silvergrass (Miscanthus sacchariflorus) is a Minnesota Department of Agriculture Restricted Noxious Weed meaning it is illegal to import, sell, or transport. 

Threat to Minnesota
  • It invades disturbed sunny to semi-shaded environments, such as roadsides, woodland borders, and clearings.
  • Although not thought to be a serious threat at this time, it forms single species stands. Landowners and managers may choose to remove it if it is found in natural areas or other areas beyond where it was planted.
What you should do

One way that invasive plant seeds and fragments can spread is in soil.  Sometimes plants are planted purposefully.  You can prevent the spread of invasive plants.

PlayCleanGo: Stop Invasive Species in Your Tracks

  • REMOVE plants, animals and mud from boots, gear, pets and vehicles.
  • CLEAN your gear before entering and leaving the recreation site.
  • STAY on designated roads and trails.
  • PLANT non-invasive species.
Native Substitutes
 
Control Methods

Mechanical control can be done by digging out the plant. All pieces of the root and rhizomes (underground stems) must be removed to prevent resprouting. Repeated mowing as short as possible during the growing season can also reduce plants over several years (see University of Minnesota management guidance for more detail). Cutting the dead stalks in the winter has no effect on the plant. Burning increases vigor of Amur silvergrass.

Herbicide control can be done using systemic herbicides such as glyphosate. Systemic herbicides are taken up by plants and move within the plant, which can kill leaves, stems, and roots. Multiple herbicide applications may be required. See University of Minnesota management guidance for a detailed description of a process for cutting, waiting for regrowth, and then applying herbicide. 

Reporting

This species is unregulated, but you can add to the public information about this species by reporting new occurrences through EDDMapS. Please only report occurrences where it is found in places where it has not been purposefully planted.

Resources

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