FIRST IMPRESSIONS: Panicum virgatum ‘Prairie Sky’ is much admired for its steely blue foliage. Mature plants are statuesque and crowned with airy summer flower panicles. In late evening, the tiny silvery spikelets seem to dance above the foliage. Winter leaves and seeds develop a soothing sandy brown color. 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. Plants are indigenous to prairies, savannas, glades, rocky bluffs, stream banks, open woods, sand dunes, marsh edges, roadsides, ditches and fields.
‘Prairie Sky’ was discovered by Landscape Architect Roger Gettig of Ohio’s Holden Arboretum. Gettig noticed the grass on a Wisconsin railroad right-of-way and selected it for the bluish teal colored foliage.
Panicum virgatum ‘Prairie Sky’ is hardy from USDA Zones 3-9.
PLANT DESCRIPTION: Panicum virgatum ‘Prairie Sky’ is an upright vase shaped switch grass cultivar.
Leaves are an intense powder blue and a bit wider than other cultvars. The young blades are erect with tips pointing up toward the sky. Older leaves are sometimes arching.
In late summer as the foliage reaches mature height, plants are topped by airy silvery flower panicles. The inflorescences consist of many small red tinged spikelets displayed on wiry stems.
Foliage holds its attractive blue color after flowering and into autumn. As winter approaches, dried seed and mature foliage develops a coppery brown tone.
This cultivar attains a 3-5’ height and 2-3’ spread.
CULTURAL & MAINTENANCE NEEDS: Panicum virgatum ‘Prairie Sky’ prospers in sunny sites with average to moist soil. Plants tolerate clay, alkalinity, drought, moderate salinity and seasonal flooding.
This cultivar is a strong quick grower that has a tendency to become loose and open as it matures. Shaded exposures, excessively rich soil, abundant water and fertilizer applications can promote stem laxness. As a result, ‘Prairie Sky’ is more likely to maintain its attractive upright habit in full sun and lean dry soil.
The only maintenance needed is to cut or burn this grass to the ground in late winter.
LANDSCAPE USES: Panicum virgatum ‘Prairie Sky’ is a useful Accent due to its electric blue foliage. This grass is appealing as a Grouping or Mass for Perennial Borders or urban Meadows. Plants provide Erosion Control, Fall Color, Winter Interest, Showy Blooms and Attractive Seedheads. This cultivar is also appropriate for Cottage Gardens, Low Maintenance Plantings and Water Wise Landscapes.
COMPANION & UNDERSTUDY PLANTS: Try pairing Panicum virgatum ‘Prairie Sky’ 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 ‘Heavy Metal’ would provide similar foliage color, cultural needs and habit. ‘Heavy Metal’ is more slender and upright with a shorter stature.
TRIVIA: Panicum virgatum ‘Prairie Sky’ is reported to have the bluest foliage of any switch grass cultivar.
Due to its Wisconsin provenance, ‘Prairie Sky’ is said have more cold hardiness than some other switch grass cultivars.