Got Lake Weeds?

Filed in In This Issue, Maintenance, On The Lake by on July 26, 2016

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By Reba Gilliand

Many of us have a picture-perfect image of lake that we carry around in our heads. We walk from our cabin or lake home over green lawn to a sandy beach where crystal clear water laps at our feet. In the distance, the clear lake reflects blue sky and white puffy clouds. We play, swim, float and dive; we sail and motor about in our boats enjoying the sun on our faces and the wind at our backs. It’s paradise.

Enter lake weeds. Cattails or bulrushes block our path to open water. Green filaments on what used to be a sandy lake bottom squish between our toes. Algae bloom prevents swimming. A thick stand of water lilies fouls the boat motor.

Faced with these obstacles to perfection, our first thoughts turn to eradication: How do I get rid of these pesky plants that are spoiling my lake paradise?

Hold on a minute. The question of what to do with lake weeds is not so simple. Here are three things to consider about removing aquatic vegetation from lakeshore property.

Aquatic vegetation is important for lake health. These plants provide cover, food, nesting and nursery habitat for fish and wildlife such asfrogs, birds, muskrats, turtles, insects, and snails. Vegetation such as cattails and bulrushes reduce wave action and protect the shoreline from erosion. Deep rooted wetland plants that grow along the shoreline and into the water buffer the lake from pollutants. Aquatic plants improve water clarity and quality. Without aquatic vegetation upon which the lake ecosystem depends, we would not have clear water, abundant fish, or attractive conditions for lake recreation.

The Minnesota Department of Natural Resources (DNR) has a say in what you can and cannot do with respect to removing aquatic vegetation on a public lake. (Public lakes are those that are 2.5 acres or larger within a city limit, or 10 acres or larger in rural areas.) The DNR is charged with protecting our lakes and waterways, and they do that in part by implementing Aquatic Plant Management Rules.

These rules spell out for lakeshore owners when and how aquatic plants can be removed from public lakes. Their purpose is to protect native vegetation and lakes from harm while allowing lakeshore homeowners control over some aquatic vegetation for water access. Visit or a DNR regional office for details of what is allowed, forbidden, or allowed only by DNR permit with respect to removing aquatic vegetation.

In general, lakeshore owners can create and maintain a swimming or boat-docking area and a boat channel to reach open water without a permit. Restrictions apply, however, as to size, type of aquatic vegetation removed, and method of removal.

A few activities and methods for removing aquatic plants are never allowed. Lakeshore owners may not excavate the lake bottom to control aquatic plants, use hydraulic jets, or use a lake bottom barrier to destroy or prevent plant growth. In addition, lakeshore owners may not remove aquatic plants where they do not interfere with swimming, boating, or other types of lake recreation, from an undeveloped shoreline, or within posted fish-spawning areas.

Permits are required from a DNR Regional Fisheries Office to remove emergent vegetation (e.g., cattails and bulrushes), submerged vegetation beyond that allowed for a boat or swimming area (e.g., Elodea), and floating-leaf vegetation beyond that allowed for a channel to reach open water (e.g., water lilies). Permits are also required to apply an herbicide or algaecide, or to use automated aquatic plant control devices such as the Crary WeedRoller.

Lakeshore owners have a number of means available for removing aquatic vegetation, some mechanical and some chemical. has a dizzying array of do-it-yourself products for cutting or pulling aquatic vegetation by hand or with equipment such as rakes, cutting blades, hand-operated, or motorized trimmers.

A relatively new product is the Lake Groomer, which is an automated aquatic plant control device. Jay Wix, General Manager at ReechCraft, Inc. describes it as effective in the operational area that it is controlling. It controls weeds and loose sediments…removes any submerged aquatic plant that is rooted to the lake bottom … prevents new weeds from germinating in the control area. To see how it works, search for Lake Groomer and select one of the many YouTube demonstrations available.

For large-scale mechanical control, hire a company to harvest aquatic plants (the DNR website maintains a current list). An advantage is one the services from these providers is to take plants to shore for disposal. The DNR requires that all plants mechanically controlled be removed from the lake, so with do-it-yourself methods, this chore is left to the lakeshore owner.

In addition to mechanical control, aquatic vegetation may be removed by applying an herbicide. The DNR website has a list of approved aquatic herbicides as well as licensed pesticide applicators for lakeshore owners who are inexperienced or uncomfortable applying herbicides themselves. These applicators frequently help obtain a permit as part of their services.

Other options include an ultra eco-friendly SCUBA diving service that pulls lake weeds out by hand by their roots. They can target specific, invasive plants, or clear an entire area. Lake stewardship. Measures such as cutting, pulling, or using herbicides can control aquatic plants from season to season, but in the long run, the best way to combat excessive growth of aquatic plants is prevention. Nutrients cause excessive plant growth. Follow good stewardship practices to keep nutrients out of the lake: limit the use of fertilizer; keep septic systems working properly; maintain a vegetative “buffer zone along the shoreline; and clean up after your pet.

Effective, and permitted, management of weeds will ensure that those images of lake paradise we all have in our head can remain a reality for future generations.

This article contains information courtesy of the DNR website.