Pondweed Removal And Control – The Ultimate Guide

Pondweed removal is a must when you have them in excess amount in your pond. There are mainly three methods of pondweed removal- Manual, Chemical and Biological.

In this article, you will learn the ways of pondweed control of all three methods.

Manual or Mechanical Method

Manual or mechanical pond weed removal is the safest method that you can adopt. To remove the weeds manually from your pond, the depth of water have to be shallow. About 3 to 4 feet depth is ok.

Submerged Pondweed

Although submerged pondweed is beneficial for oxygenation of the water, if present excessively in a pond, they can block the sunlight. Absence of sunlight in the pond decreases the natural food production and also raise a number of problems for fishes. Some common example of submerged pond weeds are Sago

• Naiad
• Coontail
• Curly Leaf Pondweed
• Hydrilla
• Milfoil
• Elodea
• Tape Grass
• Chara

1. Hand Collection in small Pond

Normally submerged pondweeds are very weak and their root system isn’t deep. In fact, some of them doesn’t have any root system at all. You will find that most of them create vines. Therefore, you can easily collect them by hand.

Before you remove them by hand, make sure you have drained the water from your pond. It will make the catching process easier for you. But if you have fish in the pond, don’t drain much water and remove the weed with care as this process can make the water murky.

2. Use a Rake to Collect Pondweed

As most of the submerged pondweed doesn’t have a strong root system and some of doesn’t have any at all, using a rake you can collect them easily.

Two types of takes are available – rakes with handle and rakes with rope. If water shallow and weed is near the shoreline then a rake with is handle works well.

Recommended pond rakes with handle and float-

• Midwest Rake Company 86036 Lake Rake with Float
• Outdoor Water Solutions PSP0212 Heavy Duty Lake and Beach Rake

For deep water and a large pond, you have to use rakes with rope. Again a rake with rope is helpful if you don’t want to get yourself into the water.

Recommended pond rakes with rope-

• SeaWeedPro Aquatic Weed Rake
• EasyPro Pond Products Aquatic Weed Rake

Pond rake with handle and rope –

• The Weed Raker by Jenlis

3. Use a Pondweed Cutter

For submerged weed with a root system, you can use weed razor or pondweed cutter. This is very easy to use tool. All you have to do is to throw it over weed area and pull the rope. When you pull it, the blades will cut the weeds. It is a lightweight tool and hence throwing is very easy.

After cutting the weeds, you have to collect them with rakes, because, if you don’t collect them, they will rot and damage the pond.

Our choice for best pond weed cutter-

• Jenlis Weed Razer
• Jenlis Weed Razer Express
• Crystal Blue Lake and Pond Weed Cutter

Shoreline or Emergent

Shoreline or emergent pondweeds are the most common problem that pond owners face. Some of the most common shoreline pondweeds are –

• Water Plantain
• Common Reed
• Bulrush
• Pickerel
• Cat Tail
• Yellow Flag Iris

They have a pretty strong root system and spread easily throughout the shoreline with seeds and other parts. Therefore, the best time to destroy them is spring when they haven’t yet produced seeds. This is why they are difficult to control. If the shoreline is shallow, they grow and spread easily. There are different practices to control them.

1. Uproot them with Hand

Uprooting is most effective for weeds with a small root system. You have to remove the weeds along with their stem and roots.

You will find some pond weed having Rhizomes, Suckers, and Runners. You have to remove these things also as weed easily grows from these things.

Once you have collected them, bury them under soil or make compost out of them so that they can’t grow again.

2. Cut them with Weeding Sickle

A sickle is a small handy tool with a curved steel blade and wooden handle. If the shoreline weeds are small in size but the stem and roots are strong, cutting and uprooting them with a sickle can be very effective.

When you use Sickle, you have to ensure some safety measures. Always wear gloves and jacket to save your hands and body from the sharp leaf of weeds.

Two types of Sickles are used for weed control. They are cheap and very easy to use for an adult.

Our recommended Sickles-

• Sickles with small blades- KNK-MT211 ARS Weeding Sickle – Nejiri Kama
• Sickles with Long Blades- Zenport K310 Brush Clearing Sickle

3. Mow them with Scythe or Grass Whip

If the weeds around your pond are tall and have created bush, there is a good possibility that snakes and harmful insects are already there.  At such a situation, using a scythe or grass whip will be safe as well as cheap.

For strong weed, Scythes are preferable over Whip.

Recommended Scythe for cutting shoreline pondweed-

• Anself Manual Steel Weed Scythe: Comes with two wooden handles and a 4’7” steel snath.

Again for grass type bushy weeds, using a Grass Whip is easy and effective.

Here is a good Whip-

• Tru Pro Grass Whip: Comes with a 40-inch handle and a reasonable price point.

4. Use a String Trimmer

Normally in the winter, the water level in pond goes down. Therefore, in winter you can use string trimmer for destroying the grass. But the disadvantage of this method is it will only work on yearly grass that propagates with the seed, not on those grows with stem or suckers.

5. Burn the Weed with a Garden Weed Burner or Hot Water

You can use a weed burner for the shoreline pondweed. This method is effective in the dry season.

Never use kerosene or any other type of oil directly for burning the weeds as it can easily mix with pond water and harm the pond habitat.

You can also use hot water for killing the weeds if your pond is small. Just pour hot water over weeds and they will be damaged overnight. If necessary, repeat the process.

6. Use Aquatic Vegetation Groomer

AVG or aquatic vegetation groomer is a new versatile way to control pondweed. They work on virtually all type of pondweed. But the only disadvantage is the high initial cost. Therefore, this tool is only recommended if you have a large commercial purpose pond.

You can use the following for grooming pondweed-

• Aquatic Weed Cutter System from Weeders Digest.

You can use it for underwater weed cutting as it comes with a sealed gearbox. It can reach up to 4 feet depth and with a floating system, it can also work over water and shoreline.

Floating

Floating pondweed are of mainly two types depending on their root system. Some weeds have their roots embedded into the soil like

• Waterlilies
• Floating Leaf Pondweed
• Spatterdock

Their main body remains under the water and only the leaf floats. On the other hand, there are completely floating pondweed with pretty small roots system like

• Duckweed
• Watermeal
• Water Hyacinth
• Water Lettuce

The freely floats and moves around the pond.

Removing Free Floating Pondweed

Duckweed Removal with Floating Net Credit: Adam Byer Koi

1. Use Floating Pipe or Rope or Net for Large Ponds

For removing small floating pondweed, you can use floating pipes or rope or net that floats in water. It’s a very economical, fast and easy way to remove duckweed, watermeal and water lettuce.

First, need to surround the floating pondweeds with any of these and slowly compress them in a small area. Then bring them near the shoreline and collect them with a skimmer.

Don’t ever leave them beside your pond. You should bury them under soil or make compost out of them so that they don’t come back to your pond with rainwater.

2. Use a Small Leaf Skimmer Rake for Small Ponds

If you have a small garden pond, then you can remove floating weeds with a pool leaf skimmer. For easy and fast removal, use a skimmer with a large opening.

Our recommended Skimmer Rakes-

• Stargoods Pool Skimmer Net
• ProTuff Pool Net Leaf Skimmer Rake

3. Use a Floating Skimmer for Large Pond

For a large pond, you can’t use a handled skimmer rake for complete removal of floating pondweed as it can’t reach the middle. But using a floating skimmer you can do this job as it floats on water and comes with rope.

First, you have to throw it into the pond and pull it to the shore by rope. Then just simply collect the weed by a rake or hand.

Here is one that we recommend-

• Parachute Skimmer

Removing Pondweed with Root Embedded into Soil by Uprooting them

The best way to get rid of pondweed with root embedded into the soil is to uproot them. Because if you don’t uproot them, they will grow again from the root.

You can uproot them with hand if the root system isn’t very strong. For strong roots, use a digger. You can also use a pond rake for weakly rooted plants. Before you start, drain water from your pond for easy removal.

Biological Method

Grass Carp for Pond Weed Control

As the name suggests, grass carp lives on aquatic vegetation and is the best fish for weed control in ponds. For controlling weeds on large pond and lakes, Grass Carp is the best biological method. Grass Carp commonly eats the following weeds.

• Bladderwort
• Cattail
• Chara/Muskgrass
• Common elodea
• Coontail
• Duckweed
• Naiad
• Potamogeton species
• Water Lilies
• Water Weed
• Watermeal
• Watermilfoil
• Water-star grass

Grass Carp has a heavy diet. They can eat 2 to 3 times their body weight and can grow up to 100 pounds. Their growth is from 5 to 10 pounds each year. Therefore, they can work on weeds for a long time one you have stocked them in your pond. Generally, they don’t reproduce in the pond so you don’t need to worry about their number in your pond.

The next question is how many of them you should stock in your pond? The population of Gras Carp in a pond for weed control depends on the amount of weed in pond. If more than 50% of the pond or is covered by weed, then you need at least 15 of them for 1 acre of water. Again if the coverage is less than 50%, 10 carp will be enough for 1 acre of water.

You should stock Grass Carp when they are 8-12 inches. At this size, their growth rate is high and effective for weed control.

After one or two years, depending on the amount of weed in your pond, you should cut their number into half. And after 3 to 4 year, you should catch them all and restock with new Grass Carp.

For stocking grass carp in your pond, you need permission from Pa Fish and Boat Commission and pay a fee.

Stock Tilapia for both Weed and Algae Control

Tilapia is a delicious tropical fish and lives on aquatic plants and algae. If you stock them in required number they work well for weed control in the pond. Commonly, the works well on the following pondweed.

• Najas
• Chara
• Duckweed
• Watermeal

Now there are two types of tilapias – the blue ones and redbelly ones. The blue tilapias work well on algae control as they can feed entirely on algae such as filamentous algae, blue-green algae. But they don’t eat plants.

But the redbelly tilapia likes to eat submerged pondweed rather than algae. Therefore, for weed control, you should stock redbelly tilapias, not the blue tilapias.

Because, if you stock blue tilapia they will eat up the algae and therefore it will have a negative effect on fish that feeds on algae.

But if you found excessive algae in your pond you can stock the redbelly tilapia too.

You should stock tilapias somewhere between April and September when the water temperature is high. For better control of pondweed, you should stock 15 to 20 pounds of tilapia for each acre of water surface. Tilapias reproduce in the pond. So if you stock both male and female, they will grow in number quickly as the reproduction rate of tilapia is high. You should catch the large ones and let the smaller ones to grow and eat up the pond weeds.

Also Read: 6 Best Blanket Weed Eating Fish

Turtles and Snails for Weed Control

Both snail and turtle feed on vegetation. Therefore, if you have a small garden pond, you can have some of them to minimize the number and growth of weeds in your pond. Turtles are good pets and their presence will increase the beauty of your pond.

Snails feed on both algae and plants. They are also good for nutrient cycling in your pond.

Duckweed Control in Ponds Biologically

Have Some Koi Carp in Small Garden Pond

Koi carp is an omnivorous fish. That means they feed on both plants and animals organisms. Therefore, for controlling small pondweeds like duckweed, Koi Carp works well. They do also eat mosquito larva.

Stock some Goldfish for Beauty and Weed Control

Just like the koi carp, goldfish also eats duckweed. In fact, it is one of their favorite food. So if your pond is covered with duckweed, you can stock some goldfish in your pond. They do reproduce in the pond and therefore the number will increase shortly. Having some goldfish along with other fish in your pond also increase the beauty of your pond.

Duck

Duckweed is named after duck and it is a favorite food of both adult and baby ducks.

If you have a small pond having 4 to 6 ducks is enough to remove all the duckweeds within a weak. But when you stock ducks in your pond make sure you don’t have small fish in it because ducks can eat them also. Again you will also need some substitute duck food for them. You can serve them both duck and chicken feed.

Again if you have a large pond that is always filled with duckweed, you can have small hard or duck. But for this, you will need an extra facility for their accommodation and substitute food. Having a duck hard is a great way to remove duckweed from your pond and earning some extra money.

Also Read: Full Duckweed Control and Removal Guide

Chemical Method

The chemical method of pondweed control solely depends on the aquatic herbicide. Pondweed control chemicals are generally known as Aquatic Herbicides.

Fluridone

Fluridone is available as Sonar and available in Sonar AS, Sonar PR, Sonar SRP, Sonar Q and Avast from different manufacturers. Sonar pond weed control very much popular for destroying Duckweed. It is one of the safest Aquatic Herbicide which doesn’t harm the pond environment and fishes.

Most Effective On

• Hydrilla
• Bladderwort
• Duckweeds
• Broadleaf watermilfoil
• Coontail
• Egeria
• Elodea
• Eurasian watermilfoil
• Fanwort
• Naiads
• Pondweeds (Potamogeton)
• Fragrant & white waterlily
• Pond edge annuals
• Spatterdock

Application:

From 0.25 to 0.5 gal/surface acre or as per manufacturer recommendation.

Remarks:

No restriction on fish consumption, watering livestock animals and swimming.

Recommended Product:

• Sonar RTU aquatic weed herbicide
• Pond Logic Wipeout
• ALLIGARE FLURIDONE AQUATIC HERBICIDE – for a large pond.

Glyphosate

Glyphosate is another safe aquatic herbicide which is available in the name of Rodeo, AquaNeat, Eagre, AquaMaster, AquaPro from different manufacturers. It has a popularity for the high effect of Cattails. On the other hand, this is cheaper than Fluridone which makes it more suitable for large Pond or Lake Weed control.

Most Effective On

• Alders
• Alligatorweed
• Arrowhead
• Cattails
• Fragrant & white waterlily
• Maidencane
• Pond edge annuals
• Rush
• Smartweed
• Southern watergrass
• Water Primrose
• Willows

Application:

4 to 7.5 pt. per surface acre of 5.4L or as per manufacturer recommendation.

Remarks:

No restriction on fish consumption, watering livestock animals and swimming.

Recommended Product:

For Small Pond-

• Applied Biochemists Aquatic Herbicide Shoreklear plus Aquatic Herbicide
• Sanco Industries Catt Plex Herbicide

For Large Pond-

• Dow Rodeo Aquatic Herbicide 2.5 gallon Glyphosate
• Roundup Custom 53.8% Glyphosate for Aquatic & Terrestrial Use 2.5 gallons

Endothall

Both the Aquathol and Hydrothol are in this group. These are available in different name and form, like, Aquathol K, Aquathol Super K and Aquathol Granular, Hydrothol 191 and its granular form.

Most Effective On

• Broadleaf watermilfoil
• Eurasian watermilfoil
• Parrotfeather
• Naiads
• Coontail
• Fanwort
• Pondweeds (Potamogeton)

Application:

For Aquathol: 0.3 to 2.6 gal/acre-foot of 4.2 L or as per manufacturer recommendation.

For Hydrothol: 0.3 to 3.4 gal/acre-foot of 2L or as per manufacturer recommendation.

Remarks:

No member of endothall has any fish consumption or swimming restriction, but you have to follow the special guideline for irrigation and watering livestock.

Recommended Product:

• Aquathol-K Aquatic Herbicide 2.5 Gallons
• Aquathol Super K 6020391

Diquat

Diquat is a widely used aquatic herbicide that is mostly available as dibromide, diquat dibromide. The action of diquat is fast as plants absorb it quickly.

Most Effective On

• Broadleaf watermilfoil
• Elodea
• Water hyacinth
• Eurasian watermilfoil
• Parrotfeather
• Frogbit
• Naiads
• Coontail
• Bladderwort

Application:

1 to 2 gallon per surface acre of 2L or as per manufacturer recommendation.

Recommended Product:

• Diquat E-PRO Aquatic Herbicide Equivalent to Reward-1 Gallon
• Crystal Blue 137 Tsunami DQ Aquatic Herbicide-37.3 Percent Diquat Dibromide-1 Quart, 32 oz
• Tsunami DQ Aquatic Herbicide – 37.3 Percent Diquat Dibromide – 1 Gallon

Remarks

No restriction of Fish Consumption and Swiming. But up to 5 days of restriction on irrigation, livestock watering, and domestic use.

2,4-D

2,4-Dichlorophenoxyacetic acid is a systemic aquatic herbicide. It works on the broadleaf pondweed. After application, it causes excessive growth of the plant and kills it as auxin-type herbicides do.

Most Effective On

• Water hyacinth
• Eurasian watermilfoil
• Parrotfeather
• Alders
• American lotus
• Arrowhead
• Buttonbush
• Fragrant & white waterlily
• Frogbit
• Smartweed
• Spatterdock
• Watershield
• Water Primrose
• Willows

Application:

1 to 2 gal/surface acre of 3.8 L or as per manufacturer recommendation.

Remarks:

The restriction of water use varies from manufacturer and formulation.

Recommended Product:

• For Small Pond- Southern Ag 2, 4 – D Amine Weed Killer
• For Large Pond – ALLIGARE 2,4 D Amine Herbicide 2.5 Gallon

Copper sulfate

Copper sulfate is widely used for algae control in lakes and ponds. But this also works well with algae type pond weeds like Nutella.

Most Effective On

• Filamentous
• Planktonic
• Branched (Chara)
• Nitella

Application:

0.6 to 3.4 gal of Chelated Copper per acre-foot or 0.1 to 0.5 ppm elemental copper or as per manufacturer recommendation.

Remarks:

No restriction on fish consumption, watering livestock animals and swimming.

Recommended Product:

• Crystal Blue Copper Sulfate Algaecide
• Applied Biochemists Aquatic Algaecide Herbicide Cutrine Plus Algaecide
• Sanco Industries Crystal Plex

To get rid of weed in your pond, the first task is to identify the weed. Then you have to select the method of removal and control. If you have fish in your pond, you have to be careful while selecting any method.