Have the cattails in your pond taken over your favorite fishing spot or crowded you from one side of the dock or swimming area?
Late summer or early fall is the best time to kill cattails, Lotus lily and other emergent plants that are on the pond’s edge or are above the water. Spraying herbicides this time of year will kill the entire plant, and it will not regrow next spring.
Starting in late summer, these plants move food to their roots for winter survival, making systemic herbicides most effective. The most common active ingredient to use is glyphosate (a few brand names with labels for aquatic use include Aqua Neat, Aqua Pro, Aquamaster, GlyphoMate 41, Pond Master, Rodeo, Shore Klear and Touchdown Pro). These can be found at local hardware, farm supply or garden stores or try an online search for “aquatic glyphosate.”
Spray the above-water portion of the plant until just wet and follow other instructions on the product label.
Many of these herbicides need a surfactant or spreader-sticker added to the mix to help it stick to the plant’s leaves. Read the label and consult with your local or online retailer for selection of a surfactant that can be used in ponds.
Consider the amount of active ingredient, need for a surfactant, and size of the container when comparing product brands. A product with a higher amount of active ingredient or one that does not need a surfactant added may provide a better value. The convenience of a ready-to-use (RTU) product that you do not have to mix or add a surfactant may override price considerations.
Be careful to:
- Always read and follow the product label for application instructions and precautions.
- Spray when calm, or when winds are low and out of a favorable direction to avoid accidentally spraying trees or other plants valuable to landscaping. Increase the droplet size of the spray to reduce drift.
- Obey State law. Shoreline owners on public waters may not use herbicides to control aquatic vegetation without a permit. Contact the DNR fisheries office near you for rules and instructions regarding removing vegetation from public waters.
Learn more about aquatic plants in ponds at www.iowadnr.gov/pondplants.