How To Best Control Pond Weeds In Your Water Feature

If you have a backyard pond, chances are you've dealt with pond weeds at some point. Read on to learn more about water weed control.

A small pond with algae and pond weeds in it.

If you have a backyard pond, chances are you’ve dealt with pond weeds at some point. These invasive species can quickly take over your pond, crowding out native plants and disrupting the natural ecosystem.

But don’t despair—there are several ways to perform pond weed control and keep your pond looking neat and tidy. Read on to learn more about water weed control.

Control Methods For Pond Weeds

Chemical Control

One of the most common methods of pond weed control is using chemicals. There are a variety of products on the market that can kill pond weeds.

However, caution is essential when applying chemicals to your pond. Many of these products can also kill fish and other aquatic life. Be sure to read the label carefully and follow the directions exactly.

Physical/Mechanical Control

If you don’t want to use chemicals, physical methods can also effectively control pond weeds. One option is to simply pull the weeds out by hand. This is often the easiest method for small ponds with only a few weeds.

Another option is to use a mechanical device such as a Weed Wrench or an Aquatic Weed Cutter. These devices can be very effective but may be too expensive for some pond owners. 

Biological Control

Biological control is another popular method for controlling pond weeds. This involves using other organisms to help control the weed population. For example, certain types of fish will eat aquatic plants. Common examples include grass carp, koi, and tilapia. Using biological control can be a great way to control pond weeds without harming other aquatic life. 

Herbicides For Pond Weed Control

Types Of Herbicides 

Two main types of herbicides can be used for pond weed control: contact and systemic.

Contact herbicides work by killing the parts of the plant that they come into contact with.

Systemic herbicides, on the other hand, are absorbed by the plant and then circulated throughout its system. This kills the entire plant from the inside out.

Both types of herbicides can be effective, so it’s a matter of personal preference as to which one you use. 

Herbicides For Controlling Pond Weeds

*While some pond contractors use pond weed herbicides, we at Charlotte Backyard Ponds do not recommend their use (except for algaecide). This is because herbicides can have a detrimental effect on a pond’s ecosystem, especially in ponds with fish. Instead, we recommend the physical removal of pond weeds.

Airmax Ultra PondWeed Defense

Airmax Ultra PondWeed Defense is a broad-spectrum herbicide designed for use in ponds. It works on all three main types of pond weeds, including floating, submerged, and emergent. Since it is a contact herbicide, it is recommended that Airmax Ultra PondWeed Defense be directly sprayed onto the weeds you are trying to eliminate. 

Airmax Shoreline Defense

The Airmax Shoreline Defense is an excellent option if you’re looking for an easy way to eliminate emergent weeds around your pond. Specifically designed to get rid of plants on the shoreline, Airmax Shoreline Defense kills the roots of persistent emergent weeds that grow above or out of the water, such as cattails.

Airmax KnockDown 2 in 1 Algae & Weed Control

If you’re looking for a 2-in-1 option for weeds and algae, Airmax KnockDown 2 in 1 Algae & Weed Control is an excellent choice. This herbicide is specifically made to eliminate invasive weeds like duckweed and watermilfoil, as well as floating algae. Airmax KnockDown 2 in 1 Algae & Weed Control also helps prevent algae growth from reoccurring.

Physical/Mechanical Removal Of Pond Weeds

A woman physically removing pond weeds from a pond.

Pond Weed Cutter

Pond weed cutters are one of the most popular tools for the mechanical removal of pond weeds. These battery or gas-powered devices feature a spinning cutting head that quickly chops through even the toughest aquatic plants. Cutters are a great option if you have a lot of pond weeds to remove, but they can be expensive and difficult to maneuver in tight spaces.

Pond Weed Rake

Pond weed rakes are another popular option for taking care of pond weeds. Rakes come in both hand-held and pole-mounted models. They’re great for removing smaller patches of weeds or for targeting specific areas.

Pond Weed Vortex

Pond weed vortexes are a newer tool that’s becoming increasingly popular for removing pond weeds. Vortexes work by using centrifugal force to suck pond weed debris into a central chamber, which can be discharged into a bag or container for easy disposal. Vortexes are excellent for large ponds with heavy weed growth. Still, they can be expensive and require regular maintenance to keep them running correctly.

Biological Control Of Pond Weeds

Introduce Natural Aquatic Weed Eaters

One way to control pond weed growth is by introducing natural aquatic weed eaters into the ecosystem. For example, grass carp are a type of fish that feeds voraciously on aquatic plants. Stocking your pond with grass carp can help keep the weed population in check. Just be sure to check with your local wildlife authority to determine if grass carp are allowed in your area before releasing them into your pond!

Use Bacteria Or Fungi

Another option is to use bacteria or fungi to kill pond weeds. Several commercial products contain these agents, so be sure to do some research to find one that’s right for your pond size and type of weed growth. Once you’ve found a product you like, simply follow the directions on the label for the best results. 

Controlling Nuisance Algae

The first step in controlling nuisance algae is to identify what type of algae you’re dealing with. There are many different types of algae, and each one responds best to different treatment methods.

Once you’ve identified the type of algae you’re dealing with, you can take steps to control it. Some standard methods for controlling nuisance algae include: 

  • Adding pond plants: Adding native plants to your water garden can help control algae. Native plants provide shade and consume nutrients that would otherwise be available for algae to grow
  • Introducing fish: Fish such as koi and goldfish consume algae as part of their diet. As a result, introducing fish into your pond can help reduce the amount of algae present
  • Adjusting pH levels: Algae thrives in slightly alkaline water. By changing the pH levels of your pond water, you can create an inhospitable environment for algae growth

If you want more information on controlling algae without the use of chemicals, be sure to check out our guide on how to naturally get rid of algae in a pond.

Types Of Aquatic Weeds

A person's hand touching the surface of a pond with floating plants in it.

Floating Pond Weeds

Floating pond weeds are aquatic plants that float on the water’s surface. They can rapidly multiply and spread, quickly covering the entire surface of a pond. While they may look harmless, floating weeds can cause severe problems for ponds and wildlife in them. 

Floating pond weeds can impede oxygen flow into the water, decreasing dissolved oxygen levels. This can be harmful to fish and other aquatic creatures. They also block sunlight from reaching the bottom of the pond, making it difficult for submerged plants to grow.

Emergent Pond Weeds

Emergent pond weeds are plants that grow in or near water and have stems that float on the surface. These include aquatic grasses, sedges, rushes, and lilies. While some emergent pond weeds can be beneficial—providing food and shelter for fish and other aquatic creatures—others can quickly take over your pond, crowding out native plants and making it difficult for fish to swim.

If left unchecked, emergent pond weeds can also lead to decreased oxygen levels in the water, which can be detrimental to both plant and animal life.

Submerged Pond Weeds

Submerged pond weeds are aquatic plants that grow entirely underwater. They typically have long, thin leaves that resemble blades of grass. Common examples of submerged pond weeds include Eurasian watermilfoil and curly-leaf pondweed. These plants can cause problems for ponds because they block out sunlight and consume oxygen that fish and other aquatic animals need. 


Algae are a type of plant that can grow in ponds, lakes, and other bodies of water. While algae are not necessarily harmful to humans, they can negatively impact a pond’s ecosystem. Algae can contribute to the depletion of oxygen levels in the water, harming fish and other aquatic creatures. Algae can also make your pond appear dirty and unkempt.

Let Charlotte Backyard Ponds Help Keep Your Backyard Pond Clean And Clear

Aquatic weeds are a nuisance every pond owner deals with at some point. You don’t have to let them ruin your beautiful backyard water feature.

If you’re having trouble with pond weeds, don’t worry! We can help. 

Fill out our contact form today, and we’ll be in touch to discuss how we can get your water feature back to beautiful.