If you have the joy of a pond on your residential property or in a business complex that you manage, you know the aesthetic and environmental benefits of these small bodies of water. However, those benefits don’t come without another side.
One of the struggles that go along with having a pond is the weeds that inevitably grow in and around the pond. In this blog post, we will give you numerous tips for how to easily remove said weeds and how to keep them from coming back.
Detriments of Weeds in Your Pond
Weeds can create a variety of headaches for a pond owner. They overgrow and prevent healthy pond plants from flourishing, as well as present a hazard for small aquatic animals such as ducks and fish. They’re also unsightly, and can even make for poor water quality. An overgrowth of weeds or algae can inhibit water movement, and stagnant water is a breeding ground for more algae growth, which exacerbates the cycle.
Solutions for Pond Weed Management
There are many things you can do to keep weeds from overtaking your pond environment. You can use the easiest of these or combine them for an even greater effect. Depending on your specific pond environment and whether or not you are tackling deep weed growth or simply preventing it from the start will also determine your course of action.
Manual or Machine Removal
A weed or algae rake can be a quick and effective way to remove a small amount of weed growth from your pond without the use of chemicals. They do require an intensive amount of labor, however, and if there is already significant growth it can be difficult to remove all of the weeds at their roots. If the weeds aren’t removed at the root, they will grow back quickly.
A large machine harvester or weed cutter is a great option for a very large pond or a body of water in which weeds have taken over. They are quite expensive, though, which can be a hindrance for homeowners. A machine-powered weed cutter is a great option for commercial properties, though, that need to keep weeds almost nonexistent.
Natural Plant or Animal Control
Carp are fish that are well-known for eating weeds and keeping ponds or lakes from excessive weed growth. There are many species of carp, though, so you will need to make sure that you check with your local wildlife department as to what species is invasive or not in your area. There are usually alternatives to invasive species that either are sterile or that will not reproduce in certain environments so that they can benefit your pond without harming the local ecosystem.
Barley straw is another biological option. When it is released into pond water and allowed to decompose naturally, it emits compounds that prevent algae plants from growing and developing. This solution can’t contend against growth that is already present, but it can prevent new growth from overtaking the body of water. It is quite safe for pond wildlife, but it does take many months to fully decompose.
There are myriad chemicals that can help with weed control, including copper sulfate, glyphosate, and various algaecides.
Copper sulfate is a powerful and effective option but it can be toxic to fish, so if you have fish in your pond make sure that the alkalinity of the water and the copper sulfate levels are compatible with the fish while killing the weeds. If you have a body of water with a low pH level it will need more copper sulfate, and this can be difficult to manage with fish life. Some algae strains can also become resistant to copper sulfate, so other options are good to have as a resource.
Glyphosate is useful for weeds that float or that have a root structure, but it is a foliar chemical so it will only kill weeds that have part of their plant above the water.
Two algaecide options are endothall and peroxygen-based granular. Sodium carbonate peroxyhydrate is a solution that keeps algae from overgrowing and prevents new blooms from taking root. It comes in a granular form that dissolves into two chemical compounds—hydrogen peroxide and sodium carbonate. Both of these bring more oxygen into the water, which prevents algae growth.
Endothall is an algaecide that is quite effective at preventing algae growth in bodies of water that are 65°F or higher, but, similar to copper sulfate, it can also be highly toxic to fish, even in very small amounts. To prevent fish death, you can apply this chemical at the shoreline of a pond and distribute it outward. If you have a larger pond area, then fish can swim away from the endothall-treated areas; however, it is not the best option for a small pond where fish do not have much room to retreat. Because of its toxicity, this product should also not be used in ponds used for irrigation.
Diquat is an herbicide that should be used before algae reaches the surface of a pond. If the water is very muddy, it will reduce the diquat’s effectiveness. This chemical is slightly toxic to fish, but not nearly at the level of copper sulfate or endothall. It should always be used per the package directions (as should all chemical pond products).
Dyes in the Water
Pond dyes actually darken the water, which can help prevent algae by preventing an excessive amount of light to hit the water. Excessive periods of high-intensity or bright lights are a catalyst for algae growth, so darkening the water can help prevent this growth. Dying pond water does not harm fish, birds, or other wildlife so it can be used without hesitation.
There are many options to help you keep the weeds under control in your pond. Take stock of all the choices and put together a plan that works best for your own ecosystem. Remember, too, that although obnoxious, weeds are plants that bring oxygen into the water, so there will need to be healthy plants in the pond as well to keep fish thriving.