Weekly “What is it?”: Phragmites

Phragmites often grows in wetlands near saltwater, and can reach heights of 15 feet or more. Photo credit: Carrie Stevenson, UF IFAS Extension

If you’ve lived in Escambia or Santa Rosa County very long, you have probably seen it while driving along Scenic Highway 90 near the railroad tracks—a tall, upright grass dominating the landscape near the water, often blocking the view of the bay.

Known as “common reed” but referred to predominantly by its genus name, Phragmites (pronounced “frag-my-tees”) is a bamboo-like grass with a resemblance to a stalk of wheat. It has a high tolerance for salt, and locally grows along Escambia Bay, Pensacola Bay, Bayou Texar, and Santa Rosa Sound. It can grow up to 15 feet tall, blocking both views and access to the water. Once it takes root, it spreads rapidly via below-ground rhizomes and above-ground stolons, which run horizontally and sprout new plants. The plant tends to form a monoculture—a dominance of one species—through the landscape. It typically thrives in disturbed areas where native salt marsh vegetation has been removed for construction, including boardwalks, roads, and railroads. Phragmites shades out smaller vegetation and prevents anything else from taking root.

Once it has taken root, Phragmites often dominates a landscape. Photo credit: Carrie Stevenson, UF IFAS Extension

Phragmites australis has been in Florida for so long that the Florida Department of Environmental Protection and IFAS Center for Aquatic and Invasive Plants consider it a native. But is it invasive? Yes. A nuisance? Absolutely. There is some debate about the makeup of the current population, with claims our Gulf Coast variety of Phragmites was brought or floated here from Europe, Africa, or Australia a very long time ago and hybridized with a native species. An exotic variety of Phragmites can be traced to ballast water in ships docking in New England in the late 1800’s. Since the mid-20th century this new species, or a hybrid thereof, spread throughout the country and was more productive, outcompeting native species. When homeowners or environmental scientists attempt to revegetate washed out and eroded shorelines, any Phragmites present is typically removed using a combination of cutting, pulling up, and herbicide treatment.

There are some environmental benefits to the species. The grass does have a large network of roots and rhizomes, holding higher marsh in place during storms. Several species of birds, including red-winged blackbirds, nest and perch in the grass. For the most part, however, that thick growth also prevents animals’ access to the water and is not considered a positive trade-off to the invasive nature of the grass.


Posted: February 2, 2021

Category: Natural Resources
Tags: Weekly What Is It

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