Undaunted Ruby Muhly Grass

Muhlenbergia reverchonii 'Undaunted'

Poaceae

• Full sun to partial shade
• 15"-18" tall × 2-3' wide
• Drought Tolerant: Yes, once established
• Warm-season grass; semi-dormant in winter
• Evergreen: No
• Flower Color/Bloom Time: Reddish-pink to ruby-red airy flower plumes (August–October)
• Wildlife Benefits: Seeds eaten by sparrows, finches, and other seed-eating birds; persistent winter seedheads provide forage and cover; deer and rabbit resistant; supports pollinators during fall bloom period

Undaunted Ruby Muhly is one of the most celebrated recent introductions to the cold-hardy xeric garden — a Plant Select® 2014 selection that brought the spectacular fall spectacle of muhly grass into climates previously too cold to enjoy it. The straight species, Muhlenbergia reverchonii, grows wild on rocky limestone slopes, hardpan seeps (hence the regional name 'Seep Muhly'), and gravelly prairies of north Texas and southwestern Oklahoma. The 'Undaunted' selection was made in 2003 by garden designers Lauren Springer and Scott Ogden from an exceptionally robust north Texas population — the original site has since been destroyed — and introduced through Plant Select, the cooperative plant program of Denver Botanic Gardens and Colorado State University. Extensive trials established its cold hardiness at a solid Zone 5, making it reliably perennial across most of the inland Northwest, including Spokane. It is notably more cold-tolerant and earlier-blooming than the popular Gulf Muhly (Muhlenbergia capillaris), which is rated only to Zone 6–7.

Through summer, the plant forms an attractive, compact, rounded mound of thin, arching, mid-green foliage with a fine texture that catches and moves gracefully in any breeze — a pleasing, low-key presence in the border that belies its fall drama. By late August into September, slender flowering stems rise above the foliage and explode into airy clouds of reddish-pink to deep ruby-red flower plumes — the showstopping quality that has made this grass a garden sensation. The effect is one of translucent color, particularly when backlit by low autumn sun, creating a luminous, glowing display of remarkable beauty. After frost, the plumes fade to warm tawny bronze and persist attractively through winter, providing structure and seed forage until cut back in late winter or early spring. Plant in groups of three or more for maximum visual impact.

Muhlenbergia reverchonii plays an important ecological role in the native grassland communities of its Texas and Oklahoma range, providing nesting material and seed forage for birds, and structural habitat for grassland invertebrates. In the garden, the persistent winter seedheads are actively foraged by sparrows, juncos, finches, and other seed-eating birds during the lean winter months — a meaningful wildlife benefit that extends the plant's season of usefulness well beyond its visual peak. The grass is highly resistant to deer and rabbit browse due to its fine-textured, relatively unpalatable foliage. It thrives in a remarkable range of soil conditions — including alkaline clay and even briefly waterlogged hardpan — mirroring its wild habitat on sites that experience extreme seasonal variation in moisture.

In the Spokane landscape, Undaunted Ruby Muhly earns its place as a premier late-season perennial grass, delivering color, movement, and wildlife value precisely when most summer perennials are finishing. Plant it in full sun for the best reddest flower color — part shade produces lighter, less saturated plumes. It performs well in borders, rock gardens, parking strip plantings, and mass plantings on slopes. It requires no division for many years and minimal care beyond cutting back old stems to a few inches in late winter before new growth begins. Outstanding companions for a late-season drama planting include Smooth Blue Aster (Symphyotrichum laeve), Missouri Goldenrod (Solidago missouriensis), Narrow-leaved Purple Coneflower (Echinacea angustifolia), Sunset Hyssop (Agastache rupestris), Douglas Aster (Symphyotrichum subspicatum), and Blue Oat Grass (Helictotrichon sempervirens). The ruby-red plumes against the blue of asters create one of the finest fall garden color combinations available.