Cattails in Ponds and Lakes: Benefits, Problems, and the Best Ways to Control Them

Walk along a pond or lake and you’ll often see tall green stalks topped with the familiar brown “hot dog” seed heads of cattails. They’re one of the most recognizable aquatic plants, providing food and shelter for countless wildlife species while helping stabilize shorelines.

But like many things in nature, balance is everything.

A small stand of cattails can improve water quality and create valuable habitat. Left unmanaged, however, cattails can quickly spread across shallow shorelines, reducing recreation, altering fish habitat, trapping sediment, and accelerating the aging of a lake.

Understanding how cattails grow—and why they sometimes become problematic—is the first step toward effective, long-term management.

This is one of the most fascinating aspects of cattails and one of the reasons they’re so difficult to control. Unlike many aquatic plants that rely mainly on seeds, cattails spread through two methods.

Each brown seed head can release hundreds of thousands of tiny seeds. These seeds are carried by wind and water to newly exposed shorelines. Seedlings establish rapidly where sunlight reaches shallow water.

Underground stems called rhizomes spread horizontally through soft sediments. Each rhizome stores carbohydrates that fuel new shoot growth every spring. One small patch can expand several feet every growing season. Over time, many individual plants become

one interconnected colony. This underground network is why simply cutting cattails rarely solves the problem.

Although they’re often viewed as weeds, cattails provide several important ecological services. They provide wildlife habitats for birds, fish, and insects. They support shoreline stabilization by holding sediments in place and reducing erosion. They absorb nutrients that fuel algal blooms. Cattails are even excellent for water filtration and trap organic matter and suspended solids in stormwater systems.

Successful cattail management rarely relies on one treatment alone. Programs commonly use mechanical removal techniques (cutting, mowing, or excavation) or herbicide applications.

Herbicide applications are the most common treatment used. Systemic herbicides such as glyphosate, imazapyr, and imazamox are commonly used because they move into the rhizomes, providing more complete control than cutting alone. The best timing is late summer through early fall, when cattails naturally move carbohydrates from the leaves into the rhizomes. Applying herbicides during this period allows the active ingredient to travel with the plant’s natural nutrient flow, increasing control of the underground root system.

Research continues to show that biological catalysts can improve systemic herbicide performance. Natural Lake Biosciences’ CattZilla® is designed to work alongside aquatic herbicides by increasing herbicide penetration into cattail tissues and accelerating the breakdown of dead stalks after treatment. University research found that combining CattZilla with glyphosate increased glyphosate penetration into cattail tissues by approximately 270% at the roots, improved cattail mortality, and caused treated plants to collapse sooner than glyphosate alone.

Faster breakdown of standing dead cattails not only improves appearance but may also reduce the prolonged gas exchange that dead stems can continue to provide through their aerenchyma tissues, limiting future regrowth opportunities.

Natural Lake Biosciences can help you develop a science-based cattail management program that combines effective herbicide strategies with biological technologies and nutrient management for longer-lasting results. Contact our team to learn more about CattZilla®, water quality testing, and customized lake management solutions.