Panicum amarum 'Dewey Blue' 

Dewey Blue panicum    Perennial of the Month-- November 2013 Perry caricature

(pan' eh-cum  ah-mar' um)  (pronunciation at link, turn up volume if too low)

Common name:  Dewey Blue bitter switchgrass

Family:  Grass, Poaceae

Height x width: 36-48' (taller with flowers) x 24-36"

Growth rate, habit: moderate, upright fountain-like

Foliage: powdery-blue (glaucous) leaves,  linear, smooth, arching near tips, average 18in. long

Flowers:  blue-tinged narrow panicle to 30in. long, Aug-Sept, seedheads turning tan; more flowers on this species than virgatum and larger

Hardiness: USDA zones 4-9

Soil:  average well-drained, prefers sandy, tolerates salty as on beaches near the ocean, tolerates poor soils and drought once established

Light:  full sun best, tolerates part shade (may flop)

Pests and problems:  none significant

Landscape habit, uses:  borders, meadows, wild or naturalized gardens, rain gardens, along watersides, wildlife gardens (cover and food for birds), erosion controland windbreak particularly on beach dunes, massed for formal effect, low screening or informal hedge, large containers, cut or dried; combines well with asters, coreopsis, yarrows, tall garden phlox, false indigo, Shasta daisy, rudbeckia, tall sedum, Joe-pye, Karl Foerster feather reed grass (blooms earlier); similar cultivars include 'Heavy Metal' and 'Prairie Sky'

Other interest: species is a beach grass, native to Atlantic and Gulf coasts; roots can grow to 6ft. deep on sandy soils; selected and named by plantsman Rick Darke for a lower Delaware coastal town;  tolerates air pollution; spreads slowly with creeping rhizomes

Other culture:  very low maintenance, tends to resist flopping better than most cultivars of switchgrass, may flop if soil is too moist, too fertile, or too low light; cut back in spring before new growth appears, to 3-4in. from crown; a warm season grass, so needs warm soils to begin growth, and warm weather for best growth

Propagation:  spring division

Sources:  many online and local specialty nurseries



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