Water Lily Control: How To Get Rid of Water Lilies

The Water Lily (also known as the White Water Lily or the Fragrant Water Lily) is a perennial plant that is known for forming dense colonies wherever they grow. You may be more familiar with the name lily pad, which is the common name used to describe the plant when it is floating on water surfaces. This plant prefers to grow in calm waters that are shallow.

Water Lilies are very useful in the natural ecosystem as they serve as habitats for many micro and macroinvertebrates. These invertebrates are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc). After Water Lilies die, the organic matter they give off through decomposition also provide food to other aquatic animals. Deer, beavers, muskrats, nutria and other rodents also consume the leaves and rhizomes of White Water Lily, while the seeds are eaten by ducks.

While they may be beneficial, they can be a problem when they begin to grow in number and overtake a water property. In some cases, water lilies can take over an entire ponds surface, making it difficult for sunlight to pass through.

If you have Water Lillies growing on your pond or other water property, our simple DIY treatment guide below can help you to get rid of water lily affordably and quickly by using our professional aquatic herbicides.

Identification

Before carrying out a treatment program, you will need to first be certain that you are dealing with Water Lily and not some other weed. Careless identification can lead to using the wrong treatment methods which can be a waste of time and money. Below we shared identifying characteristics to know what Water Lily looks like:

• Water Lilies are easy to identify as they are one of the more common floating plants people recognize. Their leaves emerge on flexible stalks from rhizomes that are on the thicker and larger side.
• The leaves are more round than the heart-shaped ones you tend to see in drawings or cartoons and are brightly colored green. Water Lilies are between 6 to 12 inches in diameter with the slit about 1/3 the length of the leaf.
• Water Lily leaves typically float on the waters surface. Flowers arise on separate stalks and have bright white petals with yellow centers. The flowers may float or stick above the water and each opens in the morning and closes in the afternoon. The flowers are very fragrant. White Water Lily can spread from seeds or the rhizomes.

Use the description and image above help you to identify whether the weed growing in your pond is Water Lily. If you need help identify the plant, contact us with a close-up high-quality photo of the plant and we will respond back with the correct plant identification.

Inspection

Once you have confirmed that you are dealing with Water Lily, proceed with inspection. During this phase, you will locate the areas where Water Lily is thriving so you know where to focus your aquatic herbicide application.

Where to Inspect

Walk around your lake or pond to observe the Water Lily and to see just how big of an infestation there is. This is important for the purpose of knowing how much herbicide you need to treat the weed. Survey your lake or pond and determine what the best and safest plan of option there is to take. You wouldnt want to harm any beneficial desired vegetation, fishes and other aquatic creatures.

This would also be a good time to test the pH of the water. What you're hoping for is a pH level below 8. Water with an 8 or higher pH level hurts the effectiveness of aquatic herbicides.

What to Look For

Water lily is a hard plant to miss. By observing your water body, you will be able to detect it pretty easily with it's floating wide leaves that are split to the stem at the center and may have white or pink flowers growing on it.

Treatment

Before handling any chemical herbicides, make sure to first put on the necessary personal protective equipment (PPE) in the form of gloves, glasses and a particle mask for safety. Our top recommended products to treat water lily is 2,4-D Selective Weed Killer. The active ingredient in this product does a great job in killing Water Lily and they also can control a large range of other aquatic weeds and land weeds you may be dealing with.

It is important to note that the 2,4-D label states that 2,4-D Amine may be toxic to fish and aquatic invertebrates in the water. To protect the aquatic life and desired vegetation within the water, apply the product in lanes separated by untreated strips. When treating continuous, dense weed masses, it may be appropriate to treat only part of the infestation at a time

Step 1 - Prepare and Mix the 2,4-D 

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).

2,4-D Applications made to aquatic weeds are done at a rate of 2 to 4 pints of product per acre. Apply using low pressure spray (10 to 40 psi) in a spray volume of 20 to 100 gallons per acre using power operated spray equipment. For hard-to-control weeds, a repeat application after 30 days at the same rate may be needed. However, do not apply more than 2 treatments per season or more than 8.42 pints per acre per season.

Step 2 - Apply 2,4-D or Glyphosate 5.4 to Water Lily

Once the herbicide of your choosing is well-mixed and depending on the targeted weed and the waters depth, you can spray the herbicide over the water along the shoreline, spot treat emerged weeds, or broadcast spray over the waters surface.

Timing is important when treating Water Lily as it is recommended to spray them between late July and first frost when the plant is actively growing. Use a fan spray nozzle to ensure an even coating on the water surface.

Step 3 - Follow Up Applications

Depending on the size of your pond or lake, you may need to conduct treatment in sections, waiting 2 weeks between treatments until you've treated the entire body of water. This is also better for the health of fish and aquatic life in the water as it allows fish to move into untreated areas and time for the chemical to break down and oxygen to return so fish can survive treatment.

Reapplication may be necessary 21 days after the initial application is complete. Water Lily can be a reoccurring issue so monitoring your water is key and repeated application is crucial to successfully getting rid of the plant.

Prevention

To keep Water Lily from coming back, we recommend applying Vision Pond Dye. Vision Pond Dye puts a stop to plant development by blocking sunlight into the water and also gives your pond a clean blue color.

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

What is Water Lily?

• Water Lily is a free-floating weed that spreads quickly over an entire water body if not treated.

How To Get Rid of Water Lily

• 2,4-D Amine Selective Weed Killer is our top recommendation for treating Water Lily and successfully removing it from a water property. Alternatively, you can use Glyphosate 5.4 which is safer to use when your water body has fish and other aquatic life.

Preventing Water Lily Reinfestation

• Applying Vision Pond Dye after treatment as a great preventative measure that prevents water lily regrowth and can restore the look of your pond, giving it a natural blue color.