Kiawah River Flora: Spartina Grass in its Spring Splendor

A telltale sign that spring has arrived in the Lowcountry is the greening of the marsh grass throughout the sea islands. Spartina grass, the smooth cordgrass that defines the salt marshes throughout our area, is sprouting new growth, reassuring us that winter months are behind us. We think this harbinger of warmer weather deserves a closer look as we welcome its vibrant green hue back to the sea islands. 

Spartina alterniflora, or smooth cordgrass as locals call it, is found throughout the coastal United States and is essential to a salt marshes’ ecosystem. Thanks to its strong root system, which spreads and interconnects rather than growing deep, spartina helps to stabilize the pluff mud in the marsh. This protects the coast against erosion by gathering more mud and sediment to increase landmass. During hurricanes and other strong storms, these strong roots disrupt wave energy and act as a wind break, lessening the impact of both strong winds and storm surge on our coastline. 

Cordgrass is also teeming with wildlife, providing a safe habitat for animals that live along the edge. During high tide, blue crabs, shrimp and red drum seek shelter and feed in the flooded grasses. Look closely during low tide and you’ll see fiddler crabs scurrying through stalks and marsh wrens picking their way through the pluff mud. Also at low tide, you’re likely to see tiny periwinkle snails clinging to the grass stalks above the waterline—where they’re escaping predators and feeding on the algae and the organic matter that the grass collects from the changing tides. 

One of the most interesting things about spartina grass is that it’s actually a freshwater plant that has adapted itself to live in the saltwater marsh. Cordgrass desalinates the water through its roots, extracting the salt and disposing of it through pores on its leaves. It can then utilize the freshwater that it has “distilled” from the salty waters of the marsh.  

Though not as beautiful as the green glow of spring, the browning and decay of the grasses in the winter also plays a very important part in the salt marsh ecosystem. When spartina dies back, it forms a “wrack” as the dead reeds are pushed to the edges of the marsh by the natural ebb and flow of the water and wind. Here, the reeds deteriorate, eventually sinking back into the mud to decay further—producing that rotten-egg smell associated with pluff mud that you either love or hate.  

Spartina is so ubiquitous in the Lowcountry that you may take it for granted. With the gradual greening of the marsh grass over the coming weeks, take time to appreciate the many benefits it offers to the sea island residents and the salt marshes that we all love so much.