Great Design Plant: Inland Sea Oats (Chasmanthium latifolium) for Shade and Erosion Control

Inland sea oats (Chasmanthium latifolium) is a showy native grass with bamboo-like wide leaves that drape elegantly over narrow stems. Native to the eastern and central U.S., it thrives in wet, shady sites and adapts to many soils.

Photo by Josiah Lau Photography

Plant Profile

• Botanical name: Chasmanthium latifolium
• Common names: Inland sea oats, Indian wood oats, wild oats, upland oats, northern sea oats
• Origin: Eastern and central U.S.
• Hardiness: USDA zones 3–11 (to 15°F)
• Water: High; prefers moist soil
• Light: Partial to full shade
• Soil: Prefers moist
• Mature size: 2–4 ft tall, 2–6 ft spread
• Benefits: Low maintenance; tolerates drought, clay, black walnut
• Seasonal interest: Green summer blooms; brown seeds persist autumn–winter
• When to plant: Transplant or sow seeds in fall

Distinguishing Traits

Among the first herbaceous plants to emerge in spring. Wide, nodding blades fall over stems; green seed heads resemble coastal sea oats (Uniola paniculata), hence the common name. Seed heads turn brown late summer, persist through winter, feeding birds.

Carex: Garden Design by Carolyn Mullet

How to Use It

Excellent for erosion control on slopes, woodland ground cover under live oaks or large trees, small spaces, courtyard gardens. Cascades beautifully over walls. Pairs well with other cascading grasses and native ferns. Group with shade-loving, moisture-loving plants. Leave foliage through winter for interest; cut back severely late winter/early spring.

Tom Mannion Landscape Design, Inc.

Carex: Garden Design by Carolyn Mullet

Planting Notes

Small areas: Buy 1-gallon containers, space 18–24 inches apart. Mulch heavily (pine bark or hay), keep thoroughly watered to establish.

Large areas — two methods:

1. Broadcast seeds: 2 lbs per 1,000 sq ft in early autumn. Hand or spreader. Use netting on slopes.
2. Plant plugs: 2–4 inch plants in trays. Space 1 ft apart, mulch with hay.