Duckweed Control: How To Get Rid of Duckweed

Duckweed is a free-floating pond weed notorious for spreading at an alarming rate and can infest a pond or quiet lake in a matter of days once established. Duckweed can be a major problem for pond owners due to its tendency for turning an aesthetically pleasing pond into an ugly mess.

Duckweed is known to spread onto ponds by migrating birds who have the plant stuck on their feathers. If left alone, Duckweed causes issues such as decreasing oxygen levels necessary for fish and desirable aquatic plants to survive.

If you have Duckweed growing on your pond or aquatic property, you can put a stop to it with the help of this informative DIY guide. Using our professional aquatic herbicides, you can get rid of Duckweed quickly and affordably.

Identification

Duckweed is often confused as algae because of the dense mats they can create on the surface of water. Duckweed is usually found on wetlands that are rich in nutrients. The characteristics of Duckweed include leaves that are shaped like the soles of shoes with a small thread-like root that hangs below the water surface.

Use our description and image to help you identify whether the plant you see is duckweed. If you are having trouble, contact us and we will help you correctly ID the plant and offer effective control recommendations.

Inspection

Where to Inspect

Duckweed grows on the surface of very stagnant bodies of water. If duckweed appears on your pond it may have been brought there by a bird. Duckweed is known to spread onto ponds by migrating birds who have the plant stuck on their feathers. Duckweed makes itself very apparent when it is in abundance as it can completely cover the water surface, depleting the water of oxygen.

What to Look For

If you have a green hue to your pond, it may not be algae. If you look closely you may see Duckweed as it has two or three leaves attached to a single root like a very small four-leaf clover. Duckweed also thrives in waters that are rich with nutrients. By addressing the reasons why there is so much richness in the water and working to reduce the amount of sediment can, along with using aquatic herbicides, help to eliminate the Duckweed problem. Aeration is one way to purify your water and decrease the need for chemicals.

Treatment

Before handling any chemicals it is essential to first put on the proper PPE for safety(gloves, glasses, mask). Our top recommended products to treat pondweed is Diquat Herbicide. Ecomazapyr 2 SL Herbicide is labeled to control Duckweed and has shown to do a great job against it. This product also carries a wide label so it can kill a large number of other unwanted aquatic weeds you may be dealing with too.

Step 1 - Prepare and Mix 

Before mixing and application, you will need to calculate the size of the water body you wish to treat to determine how much Diquat you will need. For water bodies, the measurement is usually done by calculating the acreage or acre-foot. To do this, measure the length, width, and average depth of the water body in feet then divide by 43,560 (Length (ft) x Width (ft) x Average Depth (ft) / 43,560 = Acre-feet).

According to the label, Ecomazapyr 2 SL Herbicide should be applied at 2 to 3 pints of product per acre. Do not apply more than 6 pints of this product per acre. 

Step 2 - Apply Ecomazapyr 2 SL Herbicide to target Duckweed

Once the Ecomazapyr 2 SL Herbicide is well-mixed. Depending on the targeted weed and the waters depth, you can spray the herbicide over the water along the shoreline, spot treat floating Duckweed or broadcast spray over the waters surface. Use a fan spray nozzle to ensure an even coating on the water surface.

Step 3 - Follow Up Applications

Exercise precaution and treat your pond in sections to prevent the chemical from harming other life in the water. Treat only half the pond's surface at a time. During hot weather or when treating heavy growth, it is important to treat no more than 1/3rd of your pond at a time and wait the full 14 days before re-applying.

Prevention

Unless something is done to reduce the nutrient richness in the water, Duckweed will continue to be a returning problem. Aerate your water and we also suggest using Vision Pond Dye as a product to lessen the likelihood of any vegetation growth on your pond. Vision Pond Dye limits the amount of sunlight and inhibits photosynthesis, making it hard for any invasive plant to establish.

Measure the appropriate amount of Vision Pond Dye into a bucket based on your pond area measurement findings. The label recommends applying at a rate of 1 quart per 1 surface acre of water at a 5-foot average depth.

Pour the pond dye over the edge directly into the body of water and the water's natural movement will disperse the dye.

Key Takeaways

• Duckweed is a small invasive weed that has a knack for covering up an entire pond service with its rapid growth.
• Ecomazapyr 2 SL Herbicide is the best recommendation to manage duckweed. Apply according to label directions using a handheld sprayer.
• A combination of aeration practices and Vision Pond Dye can deter duckweed from growing again on the water body.