Taming the Ornamental Beast: Controlling Miscanthus sinensis

Once celebrated for its graceful plumes and low-maintenance appeal in landscaping, Miscanthus sinensis—commonly known as Chinese silvergrass—has proven to be a wolf in ornamental clothing. This perennial grass, native to East Asia, has become increasingly invasive across parts of the United States, particularly in the Southeast and Mid-Atlantic. With its ability to thrive in disturbed areas and spread through both seed and rhizome, Miscanthus sinensis now threatens native grasslands, roadsides, and open woodlands.

Why Is It a Problem?

Though many cultivars are advertised as “sterile,” some can still produce viable seeds. These seeds are carried by wind and water, establishing dense stands that crowd out native vegetation, reduce biodiversity, and the dry stems spur wildfires in Western North Carolina. Once established, Miscanthus is remarkably resilient—thanks to its deep root system and tolerance for poor soils.

Environmentally Friendly Control Methods

Controlling Miscanthus requires persistence and a thoughtful approach, especially if you want to avoid heavy herbicide use. Here are a few ecologically sensitive strategies:

1. Manual Removal
Dig out small infestations by hand, making sure to remove all rhizomes. This works best when the soil is moist. For larger patches, mechanical removal may be necessary, though repeated effort will likely be needed.

2. Mowing and Cutting
Cutting the grass before it flowers can prevent seed spread and eventually exhaust the plant’s energy reserves. Combine mowing with other methods for better results.

3. Solarization
Covering the area with black plastic during the hot summer months can “cook” the roots and prevent regrowth. This works especially well for contained or isolated patches.

4. Mulching and Smothering
Heavy layers of mulch—especially when combined with cardboard or landscape fabric—can help suppress new shoots. Follow up by planting competitive native species to reclaim the space.

5. Targeted Herbicide Use (Last Resort)
If you must use chemicals, apply glyphosate carefully to freshly cut stems in the fall when the plant is drawing energy into its roots. Spot-treatment minimizes environmental impact.

Replanting Native Alternatives
After removal, consider planting native grasses like switchgrass (Panicum virgatum) or little bluestem (Schizachyrium scoparium). These species not only outcompete weeds but also support local wildlife.

Final Thoughts

Controlling Miscanthus sinensis is a marathon, not a sprint. But with patience, persistence, and ecological sensitivity, you can reclaim your land for native species and create a healthier, more resilient ecosystem.