Chasmanthium latifolium: Northern Sea Oats Information and Care

Chasmanthium latifolium, or northern sea oats, is a low-maintenance ornamental grass. Why grow it and how do you take care of it?

Northern Sea Oats, also known as River Oats, is a beautiful ornamental grass with drooping inflorescences and compressed spikelets. It’s a low-maintenance shade grass beloved by many.

If you are looking for an easily maintained plant that is also a great self-seeder, keep reading to learn more!

General Information

Chasmanthium latifolium is a clump-forming perennial grass that grows in the warm season.

The flat nodding seed heads, which resemble oats, emerge green in the spring, turn tan in the summer, and finally change to purple in the autumn. They gently swing with the slightest breeze. In the autumn, the bamboo-like leaves become yellow-gold if exposed to enough light.

Northern Sea Oats can be found from Pennsylvania to Florida in the east and Wisconsin to Texas in the west.

This lovely grass grows in a variety of habitats, including riverbanks and floodplains, alluvial meadows, stream and creek banks, open wet woods, and moist woodland margins.

It serves as a host plant for butterfly larvae as well as a food source for small animals and birds.

Northern Sea Oats grow to be 3 to 4 feet tall, with a spread of 2 to 3 feet.

In 1994, it was voted the North Carolina Wildflower of the Year.

A closeup picture of the leaves of a drooping plant

Care and Maintenance

Chasmanthium latifolium grows well in USDA Zones 5 to 8.

This warm-season grass grows best in moist to wet, well-drained soils in partial to full sun. Yet it tolerates shade well, especially for an ornamental grass.

The plant prefers moist, rich soil, but it will grow in ordinary, damp, loamy, clay, or rocky soil.

This grass self-seeds profusely, which can be a nuisance in small gardens. If this is an issue, deadhead or pick blossom stems before the seed matures.

The plants should be clipped down to the base rosette in early spring in cultivated settings. Foliage should be preserved all winter since it protects and insulates the plant, increases cold tolerance, and adds winter beauty.

dried leaves of a northern sea oats plant

How to Use It in Landscapes

When backlit by the sun, panicles collapse under their own weight and look very gorgeous. This lovely natural grass is great for dry, shaded areas of landscaping. Use it in naturalized areas, beside streams, or along the edges of water gardens.

Keep a watch on it, especially in smaller gardens, because rhizomes and seeds can quickly spread.

Companion Plants

The flowering plants listed below all make great companion plants for chasmanthium latifolium.

Echinacea purpurea

The purple coneflower (Echinacea purpurea) is a coarse, rough-hairy herbaceous perennial found in moist grasslands, meadows, and open forests throughout the central and southern United States. In most circumstances, it can grow to a height of 2 to 4 feet. Throughout the summer, showy daisy-like purple coneflowers bloom on stiff stalks clothed in coarse, broad, dark green leaves.

full bloom flowers of a echinacea purpurea plant

Rudbeckia fulgida

The orange coneflower (Rudbeckia fulgida) grows in full or partial sunlight in woodlands, meadows, marshes, and other mesic areas. Rudbeckia fulgida is a type of yellow daisy with brown eyes that blooms profusely. The blossoms are accompanied by beautiful green foliage, which makes it an excellent cut flower. It looks great in mass plantings.

Asclepias tuberosa

This bushy perennial grows 1 1/2 to 2 feet tall and is renowned for its big, flat-topped clusters of vivid orange blooms. The leaves are pointy, 1.5 to 2.25 inches long, and have smooth edges. The flower clusters, which range in size from yellow-orange to brilliant orange and measure 2 to 5 inches in diameter, are located near the tip of the blooming stalk. The spectacular flower heads stand out against a dark green background of stiff, lance-shaped leaves.

Cute little orange flowers of a milkweed plant
Jeffrey Douglas
Jeffrey Douglas own a landscaping company and has been in the business for over 20 years. He loves all things related to lawns or gardens and believes that proper maintenance is the key to preventing problems in the first place.
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