What Kills Cattails in Water? A Comprehensive Guide
Cattails, with their iconic brown, cylindrical flower heads, are a common sight in and around aquatic environments. While they provide valuable habitat for wildlife and play a role in shoreline protection, they can also become invasive, rapidly expanding and overtaking ponds and other water bodies. So, what effectively kills cattails in water? The most effective methods involve systemic herbicides, specifically those containing glyphosate or diquat, applied strategically and often in combination with surfactants. These herbicides are absorbed by the plant and translocate throughout the entire system, killing the roots and preventing regrowth. Other methods, like physical removal or using salt blocks, can be less effective in the long run. Let’s delve into the details.
Effective Chemical Control of Cattails
Glyphosate: The Heavy Hitter
Glyphosate is a non-selective, systemic herbicide that has consistently proven to be highly effective against cattails. It works by interfering with the plant’s ability to produce proteins essential for growth. This herbicide is most effective when applied to actively growing cattails during the growing season, typically from late summer to early fall. It’s crucial to use a formulation specifically designed for aquatic environments and follow label instructions meticulously. A standard application rate involves around 0.75 fl oz per gallon of water for some formulations; check your product for specifics. Always remember, glyphosate is non-selective, meaning it can harm other plants, so apply it carefully. The North Dakota Weed Guide recommends 4.5 pints of a 4-pound active ingredient per acre, adding a non-ionic surfactant for better coverage and absorption.
Diquat: A Powerful Contact Option
Diquat is another effective herbicide used for cattail control, particularly in aquatic settings. Unlike glyphosate, diquat is a contact herbicide, meaning it only kills the plant tissue it comes in direct contact with. It is especially useful when you need to avoid impacting adjacent terrestrial plants, or when fast visible results are needed, as it acts quickly. Diquat is often used for rapid control of the above-water portion of the plant, sometimes in combination with a systemic herbicide for more thorough results. It’s important to note that multiple applications may be necessary, as the herbicide doesn’t translocate to the roots. Products like Diquat Water Weed and Landscape Herbicide are designed specifically for aquatic weed control, making them a top choice for cattail eradication.
The Power of Surfactants
A surfactant is an essential additive to herbicide mixtures used on cattails. These additives reduce the surface tension of the water, allowing the herbicide to spread more evenly and stick to the waxy leaves of the cattails. This improved adhesion significantly increases the herbicide’s effectiveness. Commonly used surfactants include non-ionic formulations, often recommended on the herbicide product label. Using a surfactant can boost the overall efficacy of either glyphosate or diquat significantly.
Herbicide Application Techniques
The best time to apply herbicides is when the cattails are actively growing, typically between late July and the first frost. Spraying cattails during this period ensures that the herbicide is readily absorbed and transported throughout the plant. It’s critical to use a tank sprayer to apply the herbicide to the leaves that are at least 12 to 18 inches out of the water. Avoid spraying on days with rain in the forecast, as rainfall can wash away the herbicide before it has a chance to work effectively.
Other Control Methods and Considerations
While herbicides are often the most effective solution, there are alternative methods for controlling cattails, although they may be less reliable or more labor-intensive:
- Physical Removal: Cutting or mowing cattails below the waterline can help weaken the plant over time. Doing this two or three times in a season can substantially reduce regrowth the following year. However, this method is labor-intensive and often requires persistence for full control.
- Salt Blocks: Using a high-quality salt block placed at the base of the plant can be effective in some situations. The high salt concentration can dehydrate and damage the cattail’s roots. However, this method is limited to relatively small patches. Avoid pouring regular table salt directly onto the plants, as this can be detrimental to the surrounding soil and water environment.
- Water Level Manipulation: Cattails thrive in shallow water. If the water level can be altered, increasing the depth may help to drown the plants. Conversely, complete drying out of an area for an extended period can also impact cattails. However, this method is usually not practical without specific water management capabilities.
Frequently Asked Questions (FAQs)
1. Will vinegar kill cattails?
Vinegar may kill the above-ground portions of cattails but is not a permanent solution. It will likely dry them out but will not kill the roots. You will likely need to cut the plant down after applying vinegar for lasting results.
2. Is there a specific Roundup product for cattails in ponds?
While regular Roundup Pro Concentrate is not recommended for pond use, a Roundup Custom Aquatic Terrestrial Herbicide is formulated for cattail control. Always follow the product label instructions for proper application.
3. What is the best combination of herbicides for cattails?
A combination of Clearcast and SePRO MSO, at 2 ounces each per gallon of water, has been cited as an effective solution. However, always ensure the specific product is designed for aquatic use.
4. Can you get rid of cattails without harming fish?
Yes. Using selective aquatic herbicides that are specifically formulated to target cattails will minimize harm to fish and other non-target organisms.
5. Will salt kill cattails permanently?
Salt blocks can damage cattails but might not offer permanent control. Regular table salt should not be used due to its potential harm to the environment.
6. What animals eat cattails?
Several animals, including muskrats, nutrias, beavers, crayfish, some fin fish, and Canada geese consume cattails.
7. When is the best time to spray cattails?
The best time to spray cattails is between late July and the first frost when they are actively growing.
8. Does burning cattails kill them?
Burning cattails can stress the plant but usually does not kill them. However, during dry conditions, the fire might eliminate the dead plant material.
9. How deep of water will cattails grow?
Cattails typically grow in water up to 12 inches deep.
10. Is it better to cut down or spray cattails?
Cutting down cattails before late summer can stimulate new growth. Spraying them with an appropriate herbicide during their active growing phase offers a more permanent solution.
11. Are cattails beneficial in ponds?
Yes. Cattails provide important wildlife habitat, protect against erosion, and filter water. However, they can be a problem when they overgrow and become invasive.
12. What tool is used to remove cattails?
A weed puller or weed wrench is designed to extract entire cattail plants, including the roots.
13. Are cattails good for water filtration?
Yes, cattails are known for their excellent water filtration properties. They absorb pollutants and improve water quality.
14. Do cattails have deep roots?
Cattails have thick underground roots called rhizomes that extend near the edge of ponds and in shallow swales.
15. What is the recommended concentration of glyphosate for cattails?
For a 4-pound active ingredient formulation of glyphosate, use 4.5 pints per acre, adding a non-ionic surfactant. Always check product labels for specific recommendations.
By understanding the methods and considerations above, you will be well equipped to manage cattail growth in your aquatic environment, ensuring a healthy balance and thriving ecosystem.