Mexican Feather Grass

Mexican Feather Grass (Nassella tenuissima)

Silky Thread Grass, Fine-leaved Nassella

Full sun, dry to very dry, excellent drainage required — will not tolerate wet clay, pH 6.0–8.0.

1–2 feet tall, 18 inches wide; blooms May–August with fine, silky, thread-like inflorescences that move in the slightest breeze; cool-season clump-former, self-seeds prolifically.

Propagation by seed (direct sow); plants short-lived but self-replace readily — the seedling population can become the management challenge.

Native region: Not native to Tennessee; introduced from Mexico and the southwestern United States. Listed as invasive or a noxious weed in California, Nevada, New Mexico, Oregon, and parts of Australia due to prolific seeding into natural grasslands and displacement of native species.

In Middle Tennessee, Nassella tenuissima is not currently on the TDA noxious weed list, but its aggressive self-seeding warrants careful siting: avoid planting near natural areas, roadsides, or unmaintained edges where seedlings can escape. The combination of fine texture and constant motion in wind is its ornamental appeal, but this same quality — thousands of light seeds — is precisely what makes it problematic. Consider Muhlenbergia capillaris or Schizachyrium scoparium as native alternatives with similar fine texture and no invasive seed risk. If planted, deadhead before seeds mature to reduce spread.