Pond weeds are a common issue, and they can be a frustrating nuisance. At Healthy Ponds, we have some products that can help remediate issues with pond weeds, but first, let’s take a look at some common pond weeds and some preventative measures you can take that might prevent the growth of pond weeds.
Common Pond Weeds
In general, there are three types of pond weeds that you will encounter, and these include floating weeds, submerged weeds and emergent pond weeds. In small amounts, these pond weeds might not pose a problem, but pond weeds do tend to grow quickly, especially during warm or hot weather.
Floating weeds include plants such as duckweed, watermeal, water hyacinth, water lettuce, spatterdock, Azolla and water shield. These floating weeds, especially watermeal, can reproduce rapidly and cover the surface of your pond.
Submerged weeds include plants such as coontail, curly-leaf pondweed, American pondweed, Illinois pondweed, Sago pondweed and several more species. These pond weeds can reduce the oxygen levels in your pond, which is unhealthy for the fish and wildlife that live in your pond.
Emergent pond weeds, such as alligator weed and bulrush, grow on the shoreline of ponds. Other examples of emergent pond weeds include water primrose and cattails.
Chara is another invasive species that you may find in your pond. While it resembles a plant or weed, it is actually a type of algae. It is sometimes called skunkweed or muskweed because of its foul odor.
Preventing Pond Weeds
Pond weeds tend to grow in water with excess nutrients. If you can reduce the nutrient levels in your pond, you often can prevent weed growth. If your pond has a prominent sludge layer, for instance, this indicates that you have excess nutrients in your pond and reducing or removing the sludge can prevent pond weeds.
We have proactive products such as AquaSpherePRO® that can be used to prevent sludge buildup. This product contains beneficial bacteria that consume excess nutrients. These biodegradable spheres release bacteria for 30 days and then you simply add new spheres to continue treatment.
While AquaSpherePRO® is an effective and easy-to-use product, it does sometimes need additional support. For instance, if the temperatures spike, this can cause the water temperature in your pond to increase and oxygen levels can drop, which promotes the growth of pond weeds and floating organic matter.
If your area experiences a large rain event, this can cause runoff to enter the pond and upset the nutrient balance. Runoff often contains nutrients such as nitrogen and phosphorus, both of which promote the growth of pond weeds.
In these instances, we recommend using Natural BLAST® along with AquaSpherePRO®.
Natural BLAST® also contains beneficial bacteria that consume excess nutrients, and this is the ideal treatment option at the beginning of your warm season as well as when the temperature spikes or your area experiencing a significant rain event.
It’s important to note that these beneficial bacteria products don’t kill pond weeds, they simply can improve the condition of your pond water and this, in turn, can prevent or inhibit the growth of weeds and floating organic matter.
Additionally, with proper sod and grass maintenance, your lawn will better be able to soak up rainwater, which can reduce the amount of runoff in your pond. Beneficial plants around the shoreline also can prevent erosion and keep some runoff out of your pond. If you fertilize your lawn, it is recommended that you leave a buffer of lawn unfertilized around your pond, to keep the fertilizer’s nutrients out of the pond.
When you cut grass treated with fertilizer, we also recommend that you collect these clippings and dispose of them so they don’t enter your pond. Alternatively, you also could switch to using fertilizers that do not contain nitrogen or phosphorus.
If you have livestock using your pond, consider investing in some stock tanks instead of using your pond as a water source. We have an all-natural, easy-to-use stock tank cleaner that can help improve and maintain stock tank water quality and clarity. This product contains beneficial bacteria that consume excess nutrients, and this product also is designed to prevent stains, mineral deposits, odor and floating or suspended organic matter. This product is veterinarian-approved and safe for livestock, pets and people.
Pond Weed Control
Of course, if you already have an abundance of pond weeds, you will need to take other steps to remediate the issues. Floating pond weeds often can be removed manually from your pond, using a skimmer or a pond rake. With rooted pond weeds, you will need to use a weed cutter and then rake out the cut pieces.
In some cases, especially with a shallow pond, you may be able to remove the entire plant, including the root system, by hand. Keep in mind, either with raking, cutting or removing by hand, fragments left behind will cause new pond weeds to accumulate.
Herbicides and algaecides may be needed to kill these pond weeds, and Healthy Ponds has a variety of chemical products that effectively kills algae and aquatic weeds. For instance, Sonar AS might be an option for ponds covered in duckweed, watermeal, American pondweed and Eurasian watermilfoil.
When it comes to the use of any type of herbicide or algicide, it’s important to find the ideal product for your pond’s unique situation. Additionally, if your pond is stocked with fish, you will need to select products that won’t harm these fish. If you swim in the pond, you need products that won’t harm people or your pets. Fortunately, several product options are safe for fish as well as for livestock, pets and people.
You can learn more about pond weeds and potential treatment options at https://healthyponds.com/weed-definitions/. We also offer free personalized treatment plans for any size water feature at https://healthyponds.com/free-pond-plan/. If you have any questions about our products or pond weed control, don’t hesitate to contact us at any time.