Controlling Invasive Phragmites in Wisconsin: A Guide from Wisconsin Lake and Pond Resource

Invasive plant species are a serious concern for Wisconsin’s lakes, wetlands, and shorelines—and Phragmites australis, or the common reed, is one of the most aggressive. At Wisconsin Lake and Pond Resource, we help landowners, lake districts, and municipalities tackle phragmites invasions through effective, science-based control strategies. Our goal is to protect Wisconsin’s native vegetation, aquatic habitats, and recreational shorelines for the long term.

What Is Invasive Phragmites?
Phragmites is a tall perennial grass that grows in wetlands, ditches, and along the edges of lakes and rivers. While a native species of phragmites does occur in Wisconsin, the invasive variety—introduced from Europe—is highly aggressive. It can reach heights of over 15 feet and quickly forms dense stands that crowd out native plants, reduce wildlife habitat, and block access to waterways. These thick patches of non-native phragmites disrupt ecosystems and pose challenges for shoreline property owners and conservation managers alike.

Why Is Phragmites a Problem?
Invasive phragmites spreads both by windblown seeds and underground rhizomes, making it extremely hard to control once established. Left unchecked, it can:

• Displace native wetland plants
• Create poor habitat conditions for wildlife
• Obstruct water flow and shoreline access
• Increase fire risk due to dry, dense plant material

These impacts make phragmites one of the most difficult wetland invasive species to manage in Wisconsin. Effective treatment requires a long-term commitment and the right combination of strategies.

Strategies for Phragmites Control in Wisconsin
Wisconsin Lake and Pond Resource uses an integrated management approach for phragmites, combining  herbicide treatment with mechanical removal, monitoring, and restoration. We develop site-specific plans to ensure the best possible outcomes for each property.

1. Herbicide Application
   The most effective method for controlling phragmites is targeted herbicide application between late summer and early fall. During this window, the plant begins drawing nutrients into its roots for winter dormancy, which helps move herbicide into the underground rhizome system. Our licensed applicators use state-approved aquatic herbicides designed to minimize harm to native vegetation and wildlife.
2. Mechanical Removal
   After herbicide treatment, mechanical removal techniques such as mowing and cutting are used to clear dead stalks. This step improves shoreline access, enhances site appearance, and prepares the area for native plant regrowth. Mechanical removal also accelerates the decomposition of dead phragmites, which can otherwise smother native seedlings.
3. Prescribed Burning
   In some cases, especially on large wetland parcels, prescribed fire may be used following herbicide treatment. This removes accumulated biomass, reduces the seed bank, and allows native vegetation to reestablish more quickly. Burning is only conducted under safe, permitted conditions.
4. Water Level Control
   Where possible, altering water levels to submerge phragmites can stress or kill the plants. This approach is often used in conjunction with herbicide application and works best in areas where water manipulation is feasible, such as along regulated shorelines or in wetland basins.

When Should Phragmites Be Treated?
Timing is critical for effective phragmites management. In Wisconsin, the optimal treatment window is between mid-August and early October. During this period, the plant naturally begins storing energy in its rhizomes, which also helps draw in herbicide. Treating too early—while the plant is still focused on aboveground growth—often results in poor long-term control. To ensure effectiveness, treatments should occur after the plant flowers but before the first frost, and be paired with follow-up monitoring.

Long-Term Management Practices
Controlling phragmites in Wisconsin takes more than one season. Successful programs typically include:

• Assessment: Surveying the area to identify infestation levels
• Integrated Treatment: Applying a combination of herbicide, cutting and removing foliage
• Monitoring: Checking treated areas for regrowth and retreating as needed
• Habitat Restoration: Reintroducing native plants to stabilize and restore wetland health

Persistence is key—most infestations require multiple years of treatment and active monitoring to achieve lasting results.

Your Local Partner in Invasive Plant Control
At Wisconsin Lake and Pond Resource, we provide expert aquatic plant management services tailored to the unique conditions of Wisconsin’s lakes and wetlands. Whether you’re dealing with invasive phragmites along your shoreline, managing a nature preserve, or leading a lake district program, we have the tools and knowledge to help restore balance and biodiversity.

Conclusion
Invasive phragmites threatens Wisconsin’s wetlands, shorelines, and lake access. But with the right management strategies—and a dedicated, long-term plan—this aggressive species can be controlled. Wisconsin Lake and Pond Resource is proud to offer local expertise in Phragmites control in Wisconsin, using responsible, research-based methods to protect our state’s natural water resources.

Contact us today to schedule a consultation or learn more about how we can help manage invasive plants on your property.

About Wisconsin Lake & Pond Resource, A Jones Lake Management Partner

Wisconsin Lake & Pond Resource specializes in comprehensive lake and pond management solutions, including algae and aquatic weed control, aeration, hydraulic dredging, erosion control, and fisheries management. As a Jones Lake Management Partner, we serve a diverse range of clients, including HOAs, golf courses, municipalities, and private lake owners. With a commitment to science-driven strategies and environmental sustainability, Wisconsin Lake & Pond Resource helps maintain and restore aquatic ecosystems for long-term health and enjoyment.