This past weekend I was helping my mother with some yard work when I noticed that she had purchased a grass with silvery white midribs, and my suspicions were confirmed when I had a look at the label – Maiden grass (Miscanthus sinensis). Miscanthus was first introduced in the 1800s as an ornamental grass with winter interest and has now been found escaping plantings from the midwest to the east coast. This tall, clumping grass is native to East Asia, from eastern Russia through Japan.

In its native range it is often found as a dominant species in grasslands alongside bracken ferns (Pteridium aquilinum), as a codominant groundcover species in Benguet pine (Pinus kesiya) forests, and on bare ground in shrublands dominated by Miquel’s spicywintergreen (Gaultheria miqueliana). All of this is to say that it is no surprise that Miscanthus has found a comfortable home on Long Island where we have a number of native congeners and similarly nutrient poor, well drained soils. 

With 25 species of Miscanthus and roughly 100 cultivars, this plant has become a favorite in the horticultural industry as it is a cold tolerant perennial that can grow from 5 to 10 feet tall and can create dense monoclonal stands as it spreads by rhizome. It can also spread by seed, as the characteristic feathery seed heads are prolific — a single individual producing up to 1,065 in its native range, but in much warmer and wetter climates it may produce from 40,000 to 140,000 seeds. Climate change may also be playing a role in increasing the growing season for Miscanthus, allowing for more seeds to set that can be dispersed far beyond the confines of a home garden. 

Description

Flowering stalks can be seen at the level of the foliage or just above – which you can remember by it’s name, the Greek mischos meaning “stalk” and anthos meaning, “flowers.” It flowers late in the summer and holds onto its seed heads well into the fall through January. 

These flower heads consist of dense, fan shaped panicles that are roughly one foot long with 15 or more branches of paired two-flowered spikelets. At the base of each spikelet are long fine hairs, much longer than the spikelets, which give Miscanthus it’s feathery appearance. Early in season you will likely see last year’s seed heads which have a characteristic curled “witches broom” appearance. 

Individuals or ramets (individuals of clonal populations) have a vase shape with leaves that arch at the ends, which create its appealing cascading look. The leaves of Miscanthus crowd around the base and can grow up to 3’ long and from 0.8” to 4” wide with a distinctive white midrib. Cultivars of this species may also have horizontal white-yellow banding along the leaves, and others produce bright red and yellow colors in the fall.

Concern

Miscanthus has a wide range of habitats that it can exploit, and it has been found readily colonizing forest understories, grasslands, as well as roadsides and ditches. Its monotypic growth is a huge threat to the diversity of our grassland species, as well as understories of our pitch pine and oak forests. It is especially concerning in the Pine Barrens region as it not only survives fires, but likely benefits from them as it is easily able to regrow from its rhizome and exploit the newly bare soil.  It is also highly flammable making it a huge fire hazard in this fire dominated ecosystem. 

In 2019 the Pine Barrens Commission surveyed for Miscanthus along the Whiskey Road Grassland Complex and found three patches where it was invading – Whiskey Road South, Whiskey Road North, and Currans Grasslands. In the latter two grasslands, removal was done by hand digging and monitoring is ongoing to evaluate its success. In Whiskey Road South, where over 400 individuals were documented, they are planning on developing a management plan to control this population. 

One pathway of spread that has been documented throughout Long Island and especially in the Pine Barrens is illegal landscape dumping. It’s pretty scary how one small plant improperly disposed of can be the difference between maintaining the ecological integrity of an ecosystem for us and future generations to enjoy, or many years of time, money and energy spent on managing it’s removal.

Best Management Practices

Being an informed consumer of plant materials is one small way that you can prevent the establishment of an invasive species. By simply knowing its name and what it looks like, you can avoid buying and planting it in your yard. Look out for the scientific name Miscanthus sinensis on the label, or other names like Maiden Grass, Chinese Silver Grass, Japanese Silver Grass, Susuki Grass, Eulalia Grass, and Gracimllimus.

If you already have a clump of Miscanthus you can dig it up, removing as much of the roots as you can and replace with a native option (see below). 

When removing plants like Miscanthus that have numerous seeds and vigorous rooting potential, it is important to dispose of it properly. You can put the plant matter in thick black garbage bags and solarize them in the sun for a few days before placing the bags in the trash.

In places where digging up may be difficult or unfeasible, cutting off the seed heads in the fall can also help in reducing it’s spread. 

If you happen to see Miscanthus invading natural areas, be sure to take a picture of it and upload it to iMapInvasives or iNaturalist.

Alternatives

Switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardi) make for great native alternatives to Miscanthus. They are both fast growing, warm season grasses that can grow to 6 and 8 feet respectively. Switchgrass can give the homeowner that fluffy, airy look that Miscanthus provides, and big bluestem is perfect for maintaining winter interest. They are both larval hosts for the Delaware skipper butterfly, and provide habitat and forage for a variety of songbird species as well as nesting material for native bees.

Thanks to Polly Weigand at the Pine Barrens Commission and the Long Island Native Plant Initiative for providing images and greater insight on this invasive species.