Northern Sea Oats: Unconventional and attractive

Have you ever visited somewhere else with a slightly different climate or soil type and noticed a different style of landscaping or a different collection of plants that filled those landscapes?  If so, perhaps you left wondering why we don’t grow those same plants at home or whether we could if we tried. North Carolina is proud to be home to both mountains and beaches, which means we don’t have far to go in either direction to encounter new worlds of plants.

Perhaps you’ve spent some time at the beach, in which case you’ve no doubt encountered Sea oats, Uniola paniculata, a long-lived native warm-season grass used for dune stabilization. Plants grow 6 feet tall by 2 feet wide, and produce a panicle inflorescence that gives way to flat tan seedheads.

Top photo:  Sea oats are grown at the beach for dune stabilization. Middle row, left: The seed head has long slender foliage attached to stiff stems. Seed heads emerge green in spring, turn tan in summer, and purple in fall. Photo: K. Schultz, CC BY 2.0  Middle row, right: Seed head in late summer, as it begins to turn color. Photo: Klasse im Garten, CC BY 2.0 Lower row, left: Leaves and fruit. Photo: J. Robbins, CC-BY-NC-ND 4.0 Lower right: Sea oats are a clump-forming type of grass that spreads by both seeds and rhizomes. Photo: J. Robbins, CC BY-NC-ND 4.0

While you won’t see this plant much outside of its typical coastal usage, there is an alternative that, while not especially common, is a little better suited for usage throughout the rest of our state. This alternative is Northern Sea Oats, Chasmanthium latifolium, also known as River Oats, Inland Sea Oats, or Indian Wild Oats. Northern Sea Oats is a native herbaceous perennial grass, found from Central Canada, throughout the Central and Eastern United States, and Northeast Mexico, and it was named the 1994 NC Wildflower of the Year by the North Carolina Botanical Garden.

Northen Sea Oats grows to about 5 feet tall, with long slender foliage attached to stiff stems that sway in the breeze. Panicle-type flowers bloom from June to October, and form flattened seed heads that change from green to tan to purple as they mature from July through November. While a bit unconventional looking, the appearance of a mass of these seedheads is both interesting and attractive, and fits well in wildflower or natural garden plantings. It is also a good fit in plantings near bodies of water or in rain gardens.

Northern Sea Oats is a clump-forming type of grass. It spreads by both seeds and rhizomes, and some may consider it weedy due to its propensity to spread. However, as long as you provide adequate space for it to spread, it shouldn’t be problematic. As a native, it is useful in attracting and feeding a variety of butterflies, birds, and small mammals, though deer tend to leave it alone.

Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705.