Panicum amarum 'Dewey Blue'
Common Name: bitter switchgrass 
Type: Ornamental grass
Family: Poaceae
Zone: 2 to 9
Height: 3.00 to 4.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: September to February
Bloom Description: Blue tinged
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Low
Suggested Use: Naturalize, Rain Garden
Flower: Showy
Leaf: Colorful
Other: Winter Interest
Tolerate: Drought, Erosion, Dry Soil, Black Walnut, Air Pollution


Grow in average, well-drained, dry to medium moisture soils in full sun to part shade. Performs well in infertile sandy loams. May flop in overly rich soils. Will grow in light shade, but begins to lose form in too much shade, growing more openly and possibly falling over. Grows primarily in clumps, but may slowly spread by creeping rhizomes. Cut back clumps to the ground in late winter to early spring.

Noteworthy Characteristics

Panicum amarum is a clump-forming, warm season, perennial beach grass that is native primarily to sandy locations in coastal areas from Connecticut to Florida to Texas.

Genus name comes from an old Latin word for millet.

Specific epithet means bitter.

‘Dewey Blue’ is a cultivar that typically grows 3-4’ tall and is noted for its attractive powder blue foliage and fountain-like form. Blue-tinged flowers appear in late summer to early fall, followed by beige seed heads that persist well into winter. Stems reportedly retain vertical form without flopping throughout the growing season and into winter.


No known serious insect or disease problems. It is not yet fully understood how these plants will perform in the St. Louis climate.


Accent, group or mass. Borders, prairies or meadows.