Grass
Pink Muhly
Muhlenbergia sericea · Poaceae
Also called: Gulf muhly, Gulf hairawn muhly, Sweetgrass, Purple muhly, Hairawn muhly
Pink Muhly (Muhlenbergia sericea) is a low-water grass well suited to Tucson and the low desert.
Pink Muhly at a glance
- Water use
- Low (established)
- Sun
- Full sun for best pink color; tolerates light afternoon shade in the low desert, which can reduce bloom intensity.
- Mature size
- 2-3 ft H x 2-3 ft W (pink flower plumes to 3-4 ft)
- Growth rate
- Moderate; clumping warm-season bunchgrass.
- Bloom
- Spectacular airy clouds of rich pink to rosy-purple flower panicles that float above the foliage; the species' signature feature. Fades to tan as seeds mature., Fall (late September-November), a key fall-color ornamental.
- Cold hardiness
- Cold hardy to about 0-10 F; roughly USDA zones 6/7-10. Hardy in Tucson.
- Soil
- Adaptable; prefers well-drained sandy or loamy soils but tolerates a range including poor and rocky soils. Good drainage is important.
- Native range
- Native to the coastal plain and dunes of the southeastern United States (Atlantic and Gulf coasts). NOT native to Arizona or the Sonoran Desert; grown in Tucson as a non-native ornamental.
- Best used as
- Showy fall-color ornamental accent, Mass plantings and borders, Container and focal-point plantings, Backlit ornamental displays
- Wildlife
- Provides cover and nesting material; seeds eaten by birds; the dense clumps shelter small wildlife.
- Toxicity
- Non-toxic to humans, pets, and livestock.
How to grow Pink Muhly in Tucson & the low desert
Watering
Moderately drought tolerant once established; in Tucson's low desert it performs best with deep watering roughly every 1-2 weeks in summer heat, tapering in cooler months. More water than the native grasses on this list.
Fertilizer & nutrients
Low to moderate; generally thrives without fertilizer. A single light application of balanced or slow-release fertilizer in spring can support lush growth and bloom, but it is not essential.
Pruning & care
Cut back to 4-6 inches in late winter (February), before spring growth, to remove the prior season's foliage and spent plumes.
Notes
The accepted name for true Gulf/pink muhly long sold as Muhlenbergia capillaris var. filipes is now Muhlenbergia sericea; much nursery material labeled 'M. capillaris' is actually this species. Grown widely in Tucson for its dramatic fall pink plumes but is an introduced ornamental, not a Sonoran Desert native, and needs more irrigation than the region's native grasses.
Sources: AMWUA Landscape Plants for the Arizona Desert; University of Arizona Cooperative Extension; Missouri Botanical Garden Plant Finder; NC State Extension Plant Toolbox