Managing Phragmites in Wetlands and Lakes with Mechanical Removal

Mon, 02 Jul 2012 17:49:00 +0000

A fairly dry winter with very little snowfall plus near drought like conditions this summer has lead to even more aquatic plants. Another invasive species is quickly filling in exposed lake beds which are occurring due to historic low water levels. Phragmites, the Common Reed, is a large perennial grass that can grow up to 20 feet tall, not only blocking shoreline views, but it reduces habitats for a variety of animals and competes with native plants for limited resources including habitat, food, and light.

Phragmites is found on every continent except Antarctica. This colonial plant is capable of forming large stands or colonies arising from one or a few seeds or plant pieces. These colonies form along the margins of streams and in marshes and ditches. They form in brackish water and in mucky moist soil of exposed lakebed and coastal wetlands. It will grow in damp ground, in standing water up to three feet deep, and even as a floating mat.

The extensive reed beds can spread at sixteen feet or more per year by horizontal runners, which put down strong, deep roots at regular intervals. The stems grow from six feet to twenty feet tall, with thick feathery plumes of seeds. The tallest Phragmites plants are common in areas with hot summers and fertile growing conditions. Eradication of Phragmites is not likely once it successfully invades an area, but with proper control methods and annual maintenance, native plant populations can be reestablished, wildlife and wetland habitat improved, and recreational opportunities restored.

Phragmites is a very aggressive plant and outcompetes nearby vegetation for limited resources including habitat, food, and light. It grows so tall and the thick feathery plumes shade out native vegetation and makes coastal shorelines and wetlands unfit for wildlife. One study has determined that the plants growth have reduced suitable nesting habitat for several species of turtles by affecting nest temperature.

Control of Phragmites is more easily achieved in areas where growing seasons are short and plant growth is less vigorous. Control methods include spraying herbicides, mowing, discing, bulldozing, crushing, shading, dredging, flooding, draining, burning, and grazing; although a combination of treatments is most effective. After successful treatment, native plants will once again become established in these areas.

The Aquarius Systems Swamp Devil can easily chop through the thick Phragmites. This heavy duty shredder effortlessly plows through the stubborn growth while carving through the subsoil creating an open water channel up to three feet deep and eight feet wide. An aquatic weed harvester can then follow behind collecting the chopped vegetation for disposal. The Swamp Devil easily maneuvers in shallow environments such as wetlands and marshy aquatic areas.

While not specifically designed for Phragmites removal one of Aquarius Systems customers has achieved success in reclaiming a pond from the over abundance of Phragmites. An EH-220, one of our smaller aquatic weed harvesters, ran for six hours per day for six weeks to clear a 20 acre pond of Phragmites and other aquatic invasive species.

phragmites control – Aquarius-Systems

Managing Phragmites in Wetlands and Lakes with Mechanical Removal

Watch the Swamp Devil in Action