A native grass like northern sea oats comes into its own in the fall. The blades of green, which hid in the garden’s jungle of leaves all summer, turn brown and gold, and the flat, dangling seed heads change color from light green to bronze. Gardeners love this grass for the way the seed heads, which hang from arching stems, rustle and flutter in the breeze. It also thrives in part shade (unusual in an ornamental grass) and tolerates average to dry sites, making it indispensible for places where little else will grow. Birds find cover in the foliage of this clump-forming grass, and many eat the seeds.
Common name: Northern sea oats, spangle grass, river oats, wild oats
Botanical name: Chasmanthium latifolium
Plant type: Perennial grass
Zones: 5 to 9
Height: About 3 feet
Family: Poaceae
Growing conditions
• Sun: Full sun to part shade
• Soil: Average, well-drained
• Moisture: Average to wet. Will tolerate dry spots.
Care
• Mulch: Mulch to preserve moisture in the soil.
• Pruning: Cut back last year’s foliage in early spring.
• Fertilizer: None needed.
Propagation
• By seed or division
Garden notes
• Northern sea oats spreads by seeds and rhizomes. It reseeds readily, so if you don’t want it to spread, remove the seed heads before they scatter.
• Use northern sea oats in a perennial bed, along streams, or at the edge of a water garden.
• This grass is useful for dry shade.
• Finches, sparrows, cardinals, and other birds like the seeds.
All in the family
• There are only about six species in the Chasmanthium genus; all of them are perennial grasses and all are native to North and Central America. C. latifolium (formerly known as Uniola latifolia) is the most common in gardens.
• Poaceae, the grass family, also contains bamboo, rice, corn, wheat, and millet—some of the world’s most important food crops.
(Text by Elizabeth Noll, photo of Chasmanthium latifolium courtesy of the Kemper Center for Home Gardening at the Missouri Botanical Garden).