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I have a lot of water lilies in my 1/2 acre pond. How do I control them? | Ponds & Lakes Q&A

Q: I have a lot of water lilies in my 1/2 acre pond. How do I control them?

Q: I have a lot of water lilies in my 1/2 acre pond. How do I control them?

Dan – Newnan, GA

A: In ornamental ponds, water lilies planted in pots are prized possessions—but in a shallow farm pond or lake, lilies living wild can be an invasive species that takes over the water surface in no time.

Of course, water lilies aren’t all bad. Their leaves and roots provide food for beaver, moose, muskrat, porcupine, and deer. Their seeds are gobbled by waterfowl, and their leaves provide protective coverage for largemouth bass, sunfish, and frogs. Left unmanaged, however, water lilies can restrict lake-front access, eliminate swimming opportunities and quickly take over shallow areas.

But before we get into how to control these beautiful but troublesome aquatic plants, let’s learn a bit about them.

Habitat, Growth

The water lily is a floating-leaved aquatic perennial herb that grows rooted in mucky or silty sediments in water 4 to 5 feet deep. It prefers quiet waters like ponds, lake margins and slow streams. When unmanaged, the plant tends to form dense areas covering hundreds of acres.

Each spring, new shoots appear from the rhizomes and grow up through the water until they reach the surface. The flowers appear from June to September. Each blossom opens in the morning and closes in the early afternoon for two to five consecutive days. After the flowers have closed for the final time, the flower stalk corkscrews and draws the developing fruit below the water.

The plant over winters underground as the rhizome. These rhizomes, along with the plant’s seeds, are how it reproduces. A planted rhizome can grow to cover a 15-foot-diameter circle in just five years!

Limiting Those Lilies

You can control water lilies with several different methods.

  • Mechanical Control: First, you can cut/harvest the water lilies or dig up the rhizomes to create open areas of water. If you cut the lilies, you must do so several times a year as these plants thrive in shallow water and grow rapidly. If you dig up the rhizomes, it can be an intrusive and costly though permanent process; they can be difficult to dislodge, but it can be done via rotovation (underwater rototilling) or excavation. Either way, mechanical control is a difficult method because the plant will likely regrow from seeds or remaining rhizomes.
  • Chemical Control: Another more effective method is to use reactive chemical treatment, like Shoreline Defense®, to manage lilies that are actively growing and have reached the surface. When applied directly to the foliage—along with some Treatment Booster™ PLUS to break down the plant’s protective surface—the herbicide’s active ingredient penetrates the lily and makes its way to the rhizome. Once it has turned brown, use a Weed Cutter to remove as much of the decomposing plant as possible to prevent an accumulation of dead material and muck. If you use this method, treat your pond in sections, dosing only half of the lilies at a time; if the weather is hot, decrease that to a third or quarter, waiting 10 to 14 days between treatments.
  • Preventive Control: In addition to mechanical and chemical control, you can also prevent—or at least slow down—the growth of water lilies by treating the pond’s water with Pond Dye. By blocking the sun’s rays early in the season, the lilies will not get the light they need to develop.

Controlling water lilies can be a challenge. But these methods, you can manage them and keep them contained in a particular area, making them a beautiful addition to your landscape.

Pond Talk: How do you control wild water lilies in your farm pond or lake?

Kill Water Lilies and Emergent Weeds - Pond Logic(r) Shoreline Defense(r) & Treatment Booster(tm) PLUS

Should we leave cattails in the pond for the animals? | Ponds & Lakes Q&A

Q:Should we leave cattails in the pond for the animals?

Q: Should we leave cattails in the pond for the animals?

Cynthia – Greenfield, OH

A: Cattails may be a nuisance in ponds and lakes, but they’re not all bad – particularly if you’re an animal. All kinds of critters, in fact, use the plant as a source of food, shelter and supplies.

Cattail Basics

Cattails are common aquatic plants that grow from 3 to 10 feet tall in dense colonies around the margins of ponds and lakes. In the spring, the green strap-like foliage grows from large, creeping, below-the-ground rhizomes. As the seasons progress, the cattail’s leaves and spikes—or the plant’s brown cylindrical flower—grow. And when the flowers open and let loose their fluffy seeds, the cattails spread and propagate new plants throughout the lake.

Cornucopia for Critters

A small, managed area of cattails can provide an ideal habitat for amphibians, insects, birds and fish. These aquatic critters use the plants for all sorts of things, including:

  • Nesting Spot: Red-winged blackbirds often use cattails for a perching and nesting spot. Water fowl, like mallards and Canadian geese, also use the tall, tightly bunched leaves and stalks for nesting. Turkeys—as well as deer, raccoon and other mammals—use cattails as cover from predators.
  • Hatchery/Nursery: Birds and mammals aren’t the only ones that find refuge in cattails. Insects and amphibians, like dragonflies, frogs and salamanders, will lay their eggs in the brush and water between the stalks. Below the surface, fish and other aquatic creatures will hide and nest in the growth.
  • Multi-Purpose Material: The cattail fluff that explodes from the plant’s spikes makes excellent nest-making material for birds –and that’s not all it’s good for. Native Americans used it to cushion moccasins and papoose boards. Pioneers used it to dress wounds, start camp fires, and stuff quilts, cushions, mattresses and dolls. And the military used the water-resistant, buoyant fluff to stuff life vests. Besides the fluff, the cattail’s leaves were used to make mats and webbing, and the stalks were used to make fiber and adhesive.
  • Grocery Store: An integral part of the pond ecosystem’s food chain, cattails’ leaves, shoots and roots make a tasty buffet for muskrat, geese and snails, while the plant’s underwater stalks feed fish, frogs and turtles. Humans can eat cattails, too. The rhizomes can be used like other root vegetables, and they can be dried and ground into flour. Young green shoots, which taste like cucumber, can be chopped into salads. Green flowering stalks can be boiled and eaten like sweetcorn.

Pond Owner Considerations

Allowing a cattail stand to grow in your pond for the animals’ benefit is a great idea—and those critters will appreciate what you leave for them—but there are some things you should keep in mind.

If you’re trying to deter troublesome predators, like raccoon and muskrats, keep the cattails cut back. This exposes their hiding and hunting spots, so they’ll be less likely to stop by for some sushi. Use pond weed cutters and a rake to remove dead debris and growing cattails, particularly around the pond’s perimeter. While you’re at it, add some MuckAway™ to the water to help break down muck and other decomposing materials.

Your best bet is to mark out an area where you’d like your cattail stand to grow, and then clean up what grows beyond the border. You’ll provide an ecosystem for the animals while preventing your pond from being overtaken.

Pond Talk: How do you manage cattails in your pond?

Cut Through Tough Pond Weeds - The Pond Guy® 28” Weed Cutter

Should I treat my pond weeds now, or will they die on their own now that it’s getting colder? | Ponds & Lakes Q&A

Q: Should I treat my pond weeds now, or will they die on their own now that it’s getting colder?

Q: Should I treat my pond weeds now, or will they die on their own now that it’s getting colder?

Ed – Norton, OH

A: This time of year, many aquatic plants—including weeds—seem to be no longer actively growing. Triggered by dropping temperatures and fewer hours of sunlight, the cold-weather slowdown sends perennial plants into dormancy, and it can be hard to tell if they’re dead or just holing up for the winter.

Because you’ll see little or no greenery, treating those weeds can be a challenge. Plus, most chemical treatments, like herbicides and algaecides, don’t work well in colder temperatures. Algae Defense®, for example, stops working when the water is below 60°F, and the beneficial bacteria in PondClear™ almost slow down completely when temps fall below 50°F.

So what options do you have for treating weeds in the winter?

  1. Rake Out Dead Vegetation: First, pull on your muck boots and gloves, and manually pull weeds and dead foliage from the water with a weed rake or other weed removal tool. This will take out growing plants and cut down on decaying organics, which means fewer weeds and fertilizer for them next spring.
  2. Dose with Pond Dye: Next, add some Pond Dye to the water. Available in convenient liquid quarts, gallons and water-soluble packets, it will shade the water blue or black and reduce the amount of sunlight that reaches the bottom of your lake. Pond Dye can also be used regardless of the temperature or time of year.
  3. Aerate the Water: Unless you plan to use your lake for winter recreation, make sure your Airmax® Aeration System is up and running. It’ll keep your water circulated, which will reduce the muck buildup throughout the winter, and it’ll keep a hole open in the ice, which will allow for gas exchange. Your fish will thank you for it.

If you’re concerned about weeds as fall and winter approach, give these three tricks a try. By removing existing weeds and reducing the decaying buildup (i.e. weed fertilizer) now, you’ll have less work to do next spring—and won’t that be a treat!

Pond Talk: What kinds of aquatic weeds grow year-round in your area?

Protect Your Pond Year Round - Pond Logic® Pond Dye

If I treat my pond for weeds and it rains, will the treatment still work? | Ponds & Lakes Q&A

Q: If I treat my pond for weeds and it rains, will the treatment still work?

Q: If I treat my pond for weeds and it rains, will the treatment still work?

Amy – Linn Grove, IN

A: That all depends! Because you’re applying chemicals to water, you’d think that rain would have no affect on the herbicide—but it actually might. How long it rains, how heavily it rains and how soon it rained after you applied the treatment could impact its quality and effectiveness.

If wet stuff from the sky is a threat and you’re thinking about spraying algaecides or herbicides to control nuisance plants in your pond or lake, here are four general guidelines to follow:

  1. Check the Weather: Is steady rain forecast for the day? If so, postpone any treatment of emergent weeds. Many treatments need to be absorbed by the plant’s leaves to be effective. A day-long stint of rain will rinse the chemical off the weed before it can be fully absorbed.
  2. Check the Weather, Part II: If you’re expecting heavy precipitation, definitely put off treatment to another day. The applied chemical could rinse off the plants and overflow from the pond before being taken up by the target weed.
  3. Reapply If Necessary: A light sprinkle will generally not affect the chemical’s potency in a pond that’s already been treated. If a downpour occurs within a few hours of application, however, plan to reapply the herbicide in a few days to fully control that target plant.
  4. Make Your Treatment Count: Use a pond sprayer to apply the chemical as close to target weeds as possible, and use a sticky surfactant to help the chemical absorb into the plant like Treatment Booster™ PLUS. Treatment Booster™ PLUS breaks down the surface of the weed or algae and allows the active ingredient to penetrate.

Even though you’re treating aquatic weeds, wet weather can still impact the chemical’s effectiveness. Check the short- and long-term forecast and plan accordingly – because you don’t want all that hard work (and costly treatments) to be for nothing!

Pond Talk: How has the weather affected your pond or lake so far this summer?

Kill Persistent Weeds & Grasses - Shoreline Defense® & Treatment Booster™ PLUS

I think I have either milfoil or coontail. How do I tell the difference, and what chemical should I use? | Ponds & Lakes Q&A

Q: I think I have either milfoil or coontail. How do I tell the difference, and what chemical should I use?

Q: I think I have either milfoil or coontail. How do I tell the difference, and what chemical should I use?

Paul – Greenfield, OH

A: Invasive aquatic plants like milfoil and coontail can cause trouble in your pond or lake. Though they provide food and shelter for birds, insects, fish and other pond critters, they can form dense colonies, reducing access to open water, limiting fishing access, and interfering with boating and swimming.

Milfoil and coontail look similar and – thankfully – can be treated with similar chemicals. Here’s what you need to know about identifying and managing these nuisance plants.

Milfoil Identification

When you think milfoil, think feather-like.

Many different species of milfoil and watermilfoil exist in North America. In general, milfoil is found in water that’s less than 20 feet (6 meters) deep. In water less than 15 feet (4½ meters) deep, it can form dense mats over the surface. The plant is comprised of long stems with air canals and flat, feather-like, whorled leaves that are pinnately divided.

Milfoil is an important food source for waterfowl, but these nuisance plants can aggressively invade lakes, ponds and waterways. Once they’re established, they’re almost impossible to eradicate, and so periodic maintenance is necessary to keep them under control.

Coontail Identification

When coontail comes to mind, think of a Christmas tree.

Also known as hornwort, coontail also thrives in water less than 20 feet deep. The rootless invasive plant grows below the surface, and it has a central hollow stem and dark green leaves that are spiny, forked and bushy near the tip, giving it its “coontail” or Christmas tree appearance.

Like milfoil, coontail provides food for waterfowl and cover for young bluegills, perch, largemouth bass and northern pike, but it needs to be managed to prevent it from taking over your pond or lake.

Keeping Them Under Control

Many of the submerged weed chemicals available treat both milfoil and coontail. Depending how you use your pond, the best choices are:

  • Ultra PondWeed Defense®: This liquid herbicide has short-term drinking (three days for human consumption; one day for animal consumption) and irrigation restrictions (five days).
  • Navigate: A granular herbicide, Navigate is great for spot-treating problem areas. It has longer consumption and irrigation restrictions (21 days) than the others.
  • Fluridone (Sonar™): If your entire pond is infested, try Sonar™. It can kill the invaders down to their roots, but expect slower results (it can take up to 90 days for full protection) and longer irrigation restrictions (30 days). Note: Sonar™ should only be used in ponds with little to no flow.
  • Clipper™: To use Clipper™, you’ll need to mix the quick-dissolve granules with water – but you can start using the water again for irrigation in just five days.

Regardless which one you choose, the best time to apply it is when the weeds are actively growing.

Help from the Experts

If you can’t figure out which aquatic weed is growing in your pond, pull one (or more!) from the pond, snap a picture of it and send it to weedid@thepondguy.com or mail us a sample in a dry paper towel. We can help you identify the invader and suggest the best chemical to control it.

Pond Talk: What’s your go-to herbicide to treat invasive aquatic plants?

Broad Spectrum Pondweed Control - Pond Logic® Ultra PondWeed Defense®

I have water shield. What should I use, and will it hurt the lilies I want to keep? | Ponds & Lakes Q&A

Q: I have water shield. What should I use, and will it hurt the lilies I want to keep?

Q: I have water shield. What should I use, and will it hurt the lilies I want to keep?

Gordon – Spring Mills, PA

A: Water shield, scientific name Brasenia schreberi, can be a tough enemy to battle one it is established in your pond – but with some effort and the right tools this invasive aquatic plant can be controlled. Here’s what you need to know.

Water Shield Identification

Water shield, also known as Dollar Bonnet, is a floating-leaved plant that produces a small, oval pad like a water lily but without its noticeable V-shaped cutout. The leaves appear green on top and reddish-purple on the bottom and stems, and they have a distinctive gelatinous slime on their undersides. The plant also produces small, dull purple or reddish flowers that rise above the surface and consist of three to four sepals and petals.

Like other invasive aquatic plants, water shield spreads via seeds and its root system – which makes it doubly difficult to control. Beneath the surface, the long leaf stems reach the bottom where they attach to long creeping root stalks that are anchored in the mud. To control the plant, you really need to destroy the entire plant, roots and all.

Battling Water Shield

You could try to control this problem plant mechanically by cutting and yanking it with razors and rakes, but that won’t be enough to get rid of it. The plant will just regrow from its remaining roots. And if you want to attempt biological control, you’re out of luck as one doesn’t exist.

Destroying this plant means bringing out the big guns: the chemicals. Active ingredients that have been proven successful in treating water shield which include glyphosate and diquat.

Pond Logic® Shoreline Defense® Aquatic Herbicide contains glyphosate, which is a systemic killer that will work all the way down to the plant’s roots after a single use. It has no water use or temperature restrictions, so you can safely use it in ponds used for drinking water, livestock and irrigation.

Another option is Pond Logic® Ultra PondWeed Defense® Aquatic Herbicide. It’s a quick-fix solution that will kill the floating water shield foliage and tackle some other nuisance weeds in your pond. However, it may not penetrate down to the roots so you’ll need to use it repeatedly, and it has some water use restrictions associated with it.

What About the Lilies?

Both Shoreline Defense® and Ultra PondWeed Defense® should be combined with Treatment Booster™ PLUS are applied via a tank sprayer to the foliage that’s on the water surface. If you carefully spray the herbicide onto the water shield leaves on a calm day and prevent any from landing on your water lilies, they’ll be just fine!

One word of caution: Chemical control brings with it a chance of oxygen depletion caused by the decomposition of dead plant materials. If your pond is heavily infested, treat the weeds in sections, and let each section decompose for about two weeks before treating another section. Be sure to keep your aeration system running.

Pond Talk: Have you battled water shield in your pond or lake? If so, how did you win the fight?

Control Persistent Aquatic Weeds - Pond Logic® Shoreline Defense®

How can I control the duckweed in my pond? | Ponds & Lakes Q&A

Q: How can I control the duckweed in my pond?

Q: How can I control the duckweed in my pond?

Kyle – Burke, KY

A: Duckweed is a tiny menace that definitely needs to be managed. Brought to your pond or lake by humans and their equipment or on the feet and feathers of visiting waterfowl, dense colonies of these plants can proliferate and eventually cover the water surface. It’s not something you want in growing your pond.

Duckweed or Watermeal?

Duckweed a very small, light green, free-floating plant with a single hair-like root and three 1/16- to 1/8-inch long leaves, or fronds. It tends to grow in dense colonies in quiet water that’s undisturbed by waves. You can fit six to eight of these plants of the tip of your finger.

Watermeal – another invasive plant that can be mistaken for duckweed – is also light green and free-floating, but it has no roots and is more of a grainy, seed-type plant. It’s also much smaller than duckweed; at less than 1 millimeter in size, you can fit 10 to 20 of them on the tip of your finger.

Duckweed and watermeal colonies can provide a habitat for microscopic critters and forage for hungry ducks, but the plants can reduce oxygen in the water if they grow to cover a lake’s or pond’s surface. That could compromise your fishes’ health and cut off sunlight to underwater plants.

Treat Effectively

To control duckweed, think short-term and long-term.

Short Term: Ultra PondWeed Defense® or Clipper™ used with Treatment Booster™ PLUS are your go-to herbicide products for short-term control of duckweed and other invasive aquatic weeds. They provide broad-spectrum pond weed control in slow-moving water and kill what’s actively growing in your pond. If duckweed hasn’t completely taken over your water surface, you may notice algae growth mixed in with the weeds – in which case you’ll need to treat the algae first. (Pro tip: Clipper™ will control both algae and duckweed.)

Long Term: For long-term control, you’ll need an herbicide like fluridone, which is found in Sonar™ A.S. When applied in early spring (or when you begin to notice weed growth), you’ll see the product controlling established plants in 30 to 60 days, and in 90 days, you’ll have full pond protection. Because exposure to sunlight can reduce Sonar’s effectiveness, use in combination with Pond Dye. If you use your pond water to irrigate, you will need to wait 30 days following treatment.

Improve Overall Pond Health

In addition to managing your menace with herbicides, you should also reduce muck and aerate the water to keep your overall pond healthy. The products in the ClearPAC® PLUS Pond Care Package – including PondClear™, MuckAway™ and EcoBoost™ – will help reduce the submerged and suspended organic debris. Combine that with some Airmax® Aeration, and your water will stay crystal clear all season long.

Pond Talk: What else do you do to control duckweed in your lake?

Treats Floating & Submerged Weeds - Valent® Clipper™ Aquatic Herbicide