Aquatic Plant Control and Lake Management

Aquatic Plant Control and Lake Management

We provide advanced aquatic plant control for private and public clients, including home owners associations, businesses, recreation areas and cities. Our WSDA Licensed Aquatic Applicators provide accurate and sensitive herbicide treatments were appropriate, and our field crew dives, skims and extracts weeds where herbicides are not appropriate.

We use many different techniques to adequately control nuisance and noxious weeds in Washington’s ponds, lakes and rivers. Our many techniques are safe, targeted, and sustainable.

Aquatic Plant Control

Aquatic plants are an essential component to a healthy lake environment. Peninsula Environmental Group specializes in the application of aquatic herbicides and algaecides. We can serve every conceivable customer need from small sub-division ponds to large lakes.

Our staff at Peninsula Environmental Group, gives you the tools you need to keep these undesirable nuisance plants and algae in check and at desirable growth levels with our maintenance control programs.  We also provide restoration programs that restore undesirable plant and algae biomass levels to desirable and acceptable levels.  Which ever you need, APC can provide you a successful program to reach your goals without causing adverse effects to desirable flora or fauna.

Nuisance algae:

  • Interfere with recreational use
  • Produce unpleasant tastes & odors in water
  • Clog filters, pump inlets and other equipment
  • Create an ideal breeding site for mosquitoes

Nuisance aquatic plants:

  • Multiply very quickly
  • Adapt to varying environmental conditions
  • Choke canals and restrict water flow
  • Interfere with swimming & recreational sports
  • Destroy fish habitats

We control aquatic plants through all of Western Washington.

Give us a call or schedule an appointment to discuss your best options.

How We Perform Aquatic Plant Control

In-water Treatments

Simply removing the invasive plant doesn’t mean native plants will regrow into that space. Invasive plants grow faster and out-compete native flora easily. We treat the infested area then install native flora to help give native plants a much higher chance of survival and increase overall restoration success.

Ecologically Sound Techniques

We take pride in our ecological soundness. We always use the least toxic and least impactful approach to invasive plant treatments. We are licensed to treat in aquatic areas, and we use special chemical formulations that are non-toxic to salmon, amphibians and other wildlife in their applied concentrations.

Multiple Treatments

A single treatment of herbicide is rarely enough to treat these aggressive, exotic plants. Normal invasive plant control requires multiple treatments over 3+ years. Control techniques could change throughout the year, from manual removal, to broadcast herbicide, to spot applications.

Longterm Preservation

Invasive plants don’t often affect landscapes on the short-term. Thinking long-term: neglected landscapes can become inundated with unmanaged weeds resulting in serious consequences. Long-term preservation and control starts now.

Common Aquatic Weeds

European Milfoil: 

Myriophyllum spicatum is native to Europe, Asia, and north Africa, but has a wide geographic and climatic distribution among some 57 countries, extending from northern Canada to South Africa. It is a submerged aquatic plant, grows in still or slow-moving water, and is considered to be a highly invasive species.

Chinese Water Lily: 

The beautiful nature of water lilies has led to their widespread use as ornamental plants. The Mexican water lily, native to the Gulf Coast of North America, is planted throughout the continent. It has escaped from cultivation and become invasive in some areas. It can infest slow-moving bodies of water and is difficult to eradicate.


Spatterdock is a perennial, wildflower aquatic plant commonly found in shallow water pond and lakes, slow moving streams, and canals. Its extensive rhizome system allows it to grow and reproduce rapidly if not managed.  Rapid growth occurs in shallow water bodies with excess nutrients.   Dense growth interferes with recreational activities and cause light reduction of oxygen levels that can cause fish kills.

Pond Management Example


Dungeness Farms in Sequim was suffering from Class A Invasive aquatic plants within its non-tidally influenced conservation wetland. We treat the wetland three to four times per year to reduce presence of the invasive plants. Spacing treatments helps avoid decaying plants from overly reducing dissolved oxygen levels in the aquatic portions of the wetland. By reducing surface material on the lake surface, we encourage visitations by migrating ducks. Since we’ve treated, the site has seen more waterfowl presence.

Washington State Weed Control Board

For more information, or to see a complete list of exotic plants deemed noxious weeds in the Washington, please visit the Washington State Noxious Weed Control Board’s website at

Call today, or fill out the form below to start your project