Beach dune plants — Sebastian, Florida

Sea oats hold most of the beach dunes east of Sebastian, with bitter panicgrass, railroad vine, beach morning glory, seacoast marsh elder, sea purslane and sea grape filling in around them.

The dunes that matter to Sebastian are not in the city at all. They run along the barrier island on the far side of the Indian River Lagoon, from Sebastian Inlet State Park south past Ambersand, Treasure Shores and Golden Sands to Wabasso Beach. Most of that sand sits inside the Archie Carr National Wildlife Refuge, and the U.S. Fish and Wildlife Service lists beach and dunes, coastal strand and scrub, maritime hammock and mangroves among the habitats it protects there.

The plant that does the heaviest work on the dunes east of Sebastian is sea oats, a tall native grass. Around it grows a short list of specialists that tolerate salt spray, heat and dry sand: bitter panicgrass, railroad vine, beach morning glory, beach sunflower, seacoast marsh elder, sea purslane and, farther back, saw palmetto and sea grape. UF/IFAS Extension describes these species as the core of Florida's sand dune plant community, and each fills a different position on the dune between the high tide line and the hammock behind it.

Two things explain why the dunes east of Sebastian are guarded so closely. Florida law singles out sea oats and sea grapes for protection because their roots hold the beach in place, and the same dunes are nesting habitat for the sea turtles the refuge was created for. A trampled dune near Wabasso loses both functions at once.

Sea oats build the dunes between Sebastian Inlet and Wabasso by catching blowing sand in their leaves and rooting upward through each new layer as the dune rises.

Sea oats (Uniola paniculata) are the reason the foredune exists. The UF/IFAS fact sheet on the species, EDIS SG186, calls sea oats vital dune builders that accumulate sand and prevent erosion due to wind, waves, and large storms. The mechanism is simple and slow: as blowing sand is caught by the long leaves, the buried stems are stimulated to grow upward and put out new roots at each buried node, so the plant rises with the dune it is building. The same publication notes that the grass is extremely drought- and salt-tolerant and grows up to the high tide line, so on the beaches at Golden Sands or Treasure Shores it is the plant growing closest to the waves.

The plant changes height with the seasons. UF/IFAS Extension Flagler County, in a June 21, 2024 guide to dune plants, gives the leaves a height of about 1 to 2 feet, while the central flowering stem can stand 5 to 8 feet. EDIS adds that the seed heads turn straw colored as they mature, that the seed does not fully develop until fall, and that each large panicle produces very few seed. EDIS also notes the grass propagates both vegetatively and by seed in the wild, so the autumn plumes along the Archie Carr refuge beaches carry only part of each colony's reproduction.

The UF/IFAS Extension office in Indian River County notes that sea oats grow in large colonies at the very top of the sand dune or mixed among other salt- and drought-tolerant plants only a few feet further inland. The office pointed residents to the island side of Jaycee Park in Vero Beach as a public place to see these plants growing in Indian River County.

The barrier island east of Sebastian supports a small set of salt-tolerant companions to sea oats, from low vines and succulents on the seaward face to saw palmetto and sea grape behind the crest.

Sea oats rarely grow alone. The UF/IFAS dune plant guide describes bitter panicgrass (Panicum amarum) as an extremely important plant for dune stabilization that is often found mixed in with sea oats and grows quickly, which makes it useful where a dune is reestablishing after a storm or replanting. That role is visible on the Indian River County shore north of Wabasso, where the dunes were rebuilt after the 2022 hurricanes.

The low ground cover on the seaward face belongs to two vines and two succulents. Railroad vine (Ipomoea pes-caprae) is a colonizing species that moves in after disturbances such as storms. The Indian River County Extension office describes how it sends its runners across the surface of the dune and sinks tough roots down into the sand, holding the soil in place, while its leathery leaves shield the ground from rain and wind. Beach morning glory (Ipomoea imperati) is a smaller-leaved relative with white flowers. Seacoast marsh elder (Iva imbricata), also called beach elder, stores water in thick leaves, stays low and traps blowing sand, helping the foredune grow; sea purslane captures sand between its leaves and stems.

Farther back, on the crest and the landward slope that faces the Indian River Lagoon side of the island, the dune grades into shrubs. UF/IFAS lists beach sunflower, firewheel, saw palmetto and sea grape among the ten species to know. Sea grape trees can reach 35 to 50 feet and, according to the guide, block light pollution from reaching the beach, which matters on a sea turtle nesting coast like the Archie Carr refuge between Wabasso Beach and Melbourne Beach. The guide also notes sea grape is a tropical species that becomes less common northward, so its share of the dune changes along Florida's east coast.

Florida Statutes 161.242 protects sea oats and sea grapes on the beaches near Sebastian because their roots bind the sand against erosion.

The protection is written into Florida Statutes section 161.242, and its stated purpose is erosion control, not plant collecting. The statute says it exists to protect the beaches and shores of the state from erosion by preserving natural vegetative cover to bind the sand. It makes it unlawful for any purpose to cut, harvest, remove, or eradicate sea oats or sea grapes from any public land, or from private land without the owner's consent. For the public beach parks in Indian River County east of Sebastian, that means any sea oats, living or cut, are off limits.

The law also shifts the burden of proof. Possession of either plant by anyone other than the landowner is prima facie evidence of a violation, so a bundle of dried sea oat plumes carried off Golden Sands is itself the evidence. The one exception is commercial: licensed, certified nurserymen who grow the plants from seed or by vegetative propagation may sell them, because the Legislature's intent was to preserve and encourage the growth of plants it described as rapidly disappearing from the state. The statute's history line begins with chapter 65-458, a 1965 act, and the section was formerly numbered 370.041. EDIS SG186 adds that collecting sea oats in the wild for any reason requires proper permitting.

Beyond the sea oats law, the state Coastal Construction Control Line, Indian River County park ordinances and the Archie Carr refuge each keep people and construction off the dunes near Sebastian.

The state's broader tool is the Coastal Construction Control Line. The Florida Department of Environmental Protection describes the CCCL Program as regulating structures and activities that can cause beach erosion, destabilize dunes, damage upland properties or interfere with public access, and states that CCCL permits also protect sea turtles and dune plants. Seaward of that line, beachfront construction on the Indian River County barrier island from Sebastian Inlet south needs a state permit.

At the beach parks themselves, the rule is posted. Each Indian River County beach listing, including the Ambersands Beach Access page, asks visitors to stay off the dunes, defined as the vegetated areas west of the open beach, under a county ordinance. The county's Archie Carr refuge page lists a dune cross-over and unpaved parking as the only facilities at Ambersand, so the boardwalk is the sole sanctioned path through the vegetation there. UF/IFAS gives the reason in plain terms: walking on or through dunes can damage the dunes and kill plants.

The federal layer comes from the refuge. The FWS states that it established a partnership with state and county governments and private conservation groups to acquire and manage this dune habitat for sea turtles, and its visitor page describes the Barrier Island Sanctuary Trail north of Sebastian Inlet as a chance to see a maritime hammock and beach dune ecosystem from a trail rather than from the sand.

Indian River County rebuilt the dunes north of Wabasso after Hurricanes Ian and Nicole with new sand and more than 720,000 native dune plants, starting Nov. 27, 2023 at Treasure Shores Beach Park.

Hurricanes Ian and Nicole in 2022 cut deep into the Indian River County dunes, and the county answered with plants as much as sand. Vero News reported on Dec. 21, 2023 that the $13 million Sector 3 Hurricanes Ian and Nicole Dune Restoration Project began Nov. 27 at Treasure Shores Beach Park, north of Wabasso Beach, and would extend 6.6 miles south to the Turtle Trail Beach Access, with crews installing more than 720,000 native, salt-tolerant dune plants.

WPTV put the figure at approximately 728,633 native salt-tolerant dune plants and 274,368 cubic yards of sand, covering the coast from the Seaview subdivision to about half a mile south of Turtle Trail. The county's coastal staff told the station that restoring the dune was more feasible and more sea turtle friendly than building a seawall. The choice reflects the same logic as the 1965 sea oats law: on the Treasure Coast beaches east of Sebastian, rooted dune grasses are treated as part of the shore protection system, not as landscaping.