Andropogon ternarius 'Black Mountain' is a refined cultivar of splitbeard bluestem known for its upright habit, silvery blue summer foliage, and striking fluffy seed heads that emerge with a pink to purple sheen in autumn. This warm season bunchgrass is native to the southeastern United States and thrives in dry sunny locations where other grasses might falter.
Height & Spread: 36 - 48 in x 18 - 24 in
Bloom Time: Late summer to fall
Light Requirements: Full sun
Soil Preference: Well drained, sandy or rocky soils; tolerates poor fertility
Watering Needs: Low; drought tolerant once established
Deer Resistance: Generally resistant due to tough foliage texture
Native Status
Native to the southeastern and south central United States including Texas, Georgia, and the Carolinas. This cultivar is a selection bred for ornamental value while retaining the adaptability of the species.
WILDLIFE & INSECTS
Bees
- Provides habitat and foraging structure for native bees even after bloom period has ended.
Butterflies
- Supports skippers and other grass feeding caterpillars such as Cobweb, Clouded, and Whirlabout Skippers.
Birds
- Seed heads are a late season food source for finches and sparrows, while upright stems provide perching and shelter.
Beneficial Insects
- Provides overwintering cover and nesting opportunities for ground beetles, solitary wasps, and other predators of garden pests.
Spacing & Landscape Use
Spacing Recommendations:
- Allow 24 - 30 in between plants for air circulation and natural bunching form.
Landscape Placement:
- Ideal for sunny meadows, dry slopes, prairie plantings, and naturalistic designs where its seasonal change adds vertical interest.
Companion Plants
- Schizachyrium scoparium 'Standing Ovation' - Another upright native grass that provides autumnal blues and purples in sync with bluestem.
- Rudbeckia fulgida 'Goldsturm' - Offers vibrant gold daisy blooms that stand out against the airy plumes of bluestem.
- Solidago rugosa 'Fireworks' - Adds arching sprays of golden blooms that brighten dry garden corners in late season.
- Coreopsis lanceolata - Compact golden blooms add summer color and attract pollinators amid the foliage base.
- Echinacea pallida - Pale coneflower spikes add elegant height and provide structure through the seasons.