The Truth About Ms. Canthus

Miscanthus infestation.  Photo by Paul Erdmann.

This time of year, perhaps more than others, our eyes are drawn to the landscape. Trees reveal amber and gold, prairies display deep oranges, asters pop purples, and fluffy tufts of grassy seed heads sway in the wind. 


As we get caught up in this long autumn (as we should), someone must play the unfortunate role of party pooper to keep us grounded, right?  

 
Hearing no answer to the contrary, we will assume you’ve decided that the only way to peacefully return to your landscape gazing is to know the truth about a villainous vixen in our gardens, ditches and fields. Meet Ms. Canthus and her like-minded cousins.

 

Amur or Chinese silver grass (Miscanthus sinensis, Miscanthus sacchariflorus), or Ms. Canthus in my book, incorrectly referred to as pampas grass are perennial, ornamental grasses, 3-10’ tall. These plants spread and dominate, excluding and replacing beneficial native plants, resulting in a thick monoculture that is nearly impossible to walk through. It provides no known benefits to wildlife. Miscanthus sacchariflorus prefers to grow in wet places including in ditches, near stream, lake and wetland edges. This is the grass that has overtaken the cloverleaf at highways 36 and 694 in Oakdale.

 
Miscanthus species begin to bloom in late July to early August in central Minnesota. Flowers start out thin and shimmery; then become silky and/or plume-like. Fluffy flower tops may remain on plants into winter. Leaves are ½” to 1” wide x 40” long with a prominent white mid-vein. Serrated edges on the leaves can cause painful cuts.

 

Over 50 varieties exist, brought and cultivated for their aesthetic contribution to gardens, but alas, they wander far beyond. These species are spreading into road sides, woodland borders, wet and open areas, although how they do so is still somewhat of a mystery. It was previously thought that the seed of Miscanthus was sterile, but their status as an invasive species indicates that either this notion is wrong, or they have another highly-effective means such as rhizomes, root-like extensions that produce new plant shoots. A study is underway at The Ohio State University to determine this through sampling many plants and finding those that are genetically related. The Ramsey County Cooperative Weed Management Area (RCCWMA) is contributing to the study by collecting DNA and seed samples.

While some invasive species are better known such as buckthorn, sly Miscanthus is still often used in plantings. Revise your view of the landscape this fall and see that this plant can be very problematic.


The good news is that there are several other options that are equally as eye-drawing.


Native grasses such as big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), switch grass (Panicum virgatum), and Indian grass (Sorghastrum nutans), provide habitat for native wildlife while being show-stoppers, especially this time of year. Please consider replacing any plantings you may have of this invasive species with one of these Minnesota originals. 

Little bluestem is a native plant that makes
a great substitution to miscanthus.

 
You may now return to your regularly scheduled autumn viewing. 



[RCCWMA receives support from Ramsey Conservation District, RWMWD and the Minnesota Board of Soil and Water Resources. Check your yard and neighborhood for species on our watch list: https://www.co.ramsey.mn.us/cd/cwma.htm.]