FIRST IMPRESSIONS: Panicum virgatum ‘Heavy Metal’ is a switch grass selection with a dramatically vertical habit. Foliage and stems are erect with metallic blue blades. In summer airy pinkish flower panicles seem to dance in the evening light. Foliage turns golden in autumn and develops a golden brown winter color. ‘Heavy Metal’ 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 United States. Plants are indigenous to prairies, savannas, glades, rocky bluffs, stream banks, open woods, sand dunes, marsh edges, roadsides, ditches and fields.
Panicum virgatum ‘Heavy Metal’ was introduced in Kurt Bluemel’s Maryland nursery during the 1980’s. This grass was selected for its columnar habit and metallic blue foliage.
Panicum virgatum ‘Heavy Metal’ is hardy from USDA Zones 4-9.
PLANT DESCRIPTION: Panicum virgatum ‘Heavy Metal’ is a narrowly upright bunch grass that produces many vertical culms from short rhizomes.
The linear leaves are arranged alternately on blue-green glaucous stems. The erect blades have a steely blue color and a pleasing yellow fall color.
In late summer as the foliage reaches mature height, it is crowned by open airy flower panicles. The cloud-like inflorescence contains many small pinkish-mauve spikelets displayed on wiry stems.
Seed and foliage develops a glowing straw color in winter that is reminiscent of grain sheaves.
Leafy growth is about 3’ tall and 1-2’ wide. Blooms rise above the foliage to about 5’.
CULTURAL & MAINTENANCE NEEDS: Panicum virgatum ‘Heavy Metal’ prospers in sunny sites with average to moist soil. The preference is for moist sandy or clay soil.
This grass will grow in part shade but stems often become lax and plants tend to lose their lovely columnar form. Excessively rich soil, abundant water and fertilizer applications should be avoided as these practices promote stem weakness.
Plants tolerate clay, alkalinity, drought, moderate salinity and seasonal flooding.
The only maintenance needed is to cut or burn this grass to the ground in late winter.
LANDSCAPE USES: Panicum virgatum ‘Heavy Metal’ has a stiff narrow habit and short stature that is in scale with small residential gardens. This grass is an appealing Accent or Grouping for Perennial Borders, Green Roofs 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, Water Wise Landscapes and Rain Gardens.
COMPANION & UNDERSTUDY PLANTS: The intense powder blue foliage of ‘Heavy Metal’ is the perfect foil for the golden flowers of Rudbeckia fulgida var. fulgida, Coreopsis tripteris and Solidago rugosa ‘Fireworks’. Other appropriate bed fellows include Aster laevis ‘Bluebird’, Aster oblongifolius ‘Raydon’s Favorite’, Echinacea purpurea or Schizachyrium scoparium ‘Prairie Munchkin’.
If a substitute is needed, Panicum virgatum ‘Northwind’ has similar cultural needs and habit. Schizachyrium scoparium 'The Blues' is another possible stand-in with a similar stiff upright habit and metallic blue foliage.
TRIVIA: This was among the earliest switch grass cultivars to be introduced. And yet, it still has a following. Recently it was recommended and planted in masses in Chicago’s well-known Lurie Garden.