FIRST IMPRESSIONS: Panicum virgatum 'Shenandoah' is a popular switch grass cultivar that is known for its compact habit and striking red-purple fall color. In summer airy reddish-pink flower panicles rise above burgundy highlighted leaves. The panicles turn soft beige in autumn as foliage intensifies to a deep wine red. The winter leaves and seed heads develop an attractive amber glow. This handsome grass thrives in prairie type settings or in sunny gardens with moist, average or dry soils.
HABITAT & HARDINESS: The parent species Panicum virgatum ranges through most of the southern Canadian provinces and the contiguous United States. The species is indigenous to prairies, savannas, glades, rocky bluffs, stream banks, open woods, sand dunes, marsh borders, roadsides, ditches and fields.
Dr. Hans Simon introduced ‘Shenandoah’ at his German nursery. Simon selected the plant from a batch of seedlings of Panicum virgatum ‘Hanse Hermes’. He chose the seedling for its short compact habit and improved red color. Simon named the plant for Virginia’s Shenandoah Valley as a tribute to the species’ country of origin.
Panicum virgataum ‘Shenandoah’ is hardy from USDA Zones 4-9.
PLANT DESCRIPTION: Panicum virgatum 'Shenandoah' is an elegant and compact vase shaped switch grass cultivar with four seasons of interest.
The attractive foliage and sturdy stems are blue green as they emerge in spring. By early summer blade tips are highlighted with bright burgundy red.
Later in summer as the foliage reaches mature height, nebulous flower panicles appear. They consist of many small reddish-pink spikelets displayed on wiry stems.
In fall the ripe seed turn soft tan, forming a nice contrast to the deep purplish-red foliage. Then as winter approaches, dried seed and foliage develop a coppery winter hue.
Plants are 2-3’ tall with 2’ spread.
CULTURAL & MAINTENANCE NEEDS: Panicum virgatum 'Shenandoah' prospers in sunny sites with average to moist soil.
Plants tolerate clay, alkalinity, drought, moderate salinity and seasonal flooding. Excess shade, fertilizers and abundant water can promote weak sprawling stems and should be avoided.
The only maintenance needed is to cut or burn this grass to the ground in late winter.
LANDSCAPE USES: Due to its uniform habit and brilliant fall color, Panicum virgatum ‘Shenandoah’ is an appealing Accent, Grouping or Mass Planting for Perennial Borders or urban Meadows. Plants provide Erosion Control, Fall Color, Winter Interest, Showy Blooms and Attractive Seedheads and are appropriate for Cottage Gardens, Low Maintenance Plantings, Rain Gardens and Water Wise Landscapes.
COMPANION & UNDERSTUDY PLANTS: Try pairing Panicum virgatum ‘Shenandoah’ with Aster laevis ‘Bluebird’, Aster oblongifolius ‘Raydon’s Favorite’, Echinacea purpurea, Rudbeckia fulgida var. fulgida, Solidago rugosa ‘Fireworks’ or Schizachyrium scoparium ‘Standing Ovation’.
If a substitute is needed, Panicum virgatum ‘Rotstrahlbusch’ would provide similar foliage color, cultural needs and habit. ‘Rotstrahlbusch’ is a larger plant, however.
TRIVIA: Panicum virgatum 'Shenandoah' received France’s prestigious Mérites de Courson award in 2003.
This cultivar is widely used in the design work of Piet Oudolf. In New York City’s High Line, Oudolf selected ‘Shenandoah’ as a matrix plant which would “dominate… the planting, forming a matrix into which other plants are blended.”
‘Shenandoah’ is acknowledged as the brightest red switchgrass cultivar currently in the nursery trade. Foliage is red enough to be mistaken for the lovely but terribly invasive Japanese blood grass.