Identifying and Controlling Microstegium (Japanese Stiltgrass)

The Summer Weed That Refuses to Leave

If you garden in the Southeast, you likely know this grassy invader by its frustrated nickname: "That summer weed I can pull out by the handful, only to watch it return weeks later." Formally known as Microstegium vimineum—commonly called Japanese stiltgrass, basketgrass, or eulalia—this annual weed thrives in shady, disturbed soils. It creeps along garden edges, hides beneath newly planted shrubs, and colonizes the margins of new construction sites.

Why It’s So Persistent

Native to Asia, Japanese stiltgrass was first recorded in Tennessee in 1919 and has since spread across the Eastern Seaboard. In Georgia, it lines nearly every creekside and flourishes in moist, shaded landscapes. Because it has no natural enemies here, the only controls are manual removal and herbicides. Recent research into a pathogenic fungus offers hope for a future biological control, but for now, persistence is key.

Pre-Emergent Strategy

Applying a pre-emergent herbicide prevents seed germination. Since seeds sprout throughout summer, two applications—mid-February and early May—are recommended. Heavy infestations may warrant a third treatment in July. Always follow label directions.

Selective Post-Emergent Control

Grass-selective herbicides containing fluazifop kill actively growing stiltgrass without harming most broadleaf ornamentals. Check the label for a list of safe target plants.

Non-Selective Option

Glyphosate will eliminate stiltgrass, but it also kills everything else it touches. Using it leaves bare soil—an open invitation for new weeds. Reserve this for areas where you plan to replant immediately.

Vigilance Is Essential

Even a single missed sprig can re-colonize a bed of hostas and ferns within weeks. Combine pre-emergent applications with timely hand-pulling or selective spraying for the best long-term results.

New Threat: Wavyleaf Basketgrass

A related invader, Oplismenus undulatifolius (wavyleaf basketgrass), is now appearing in shaded gardens. Its identification and control are similar, but early detection is critical.