Eradicating weeds from ponds improves the appearance of the water. According to the University of Missouri, there are some basic methods of controlling pond weeds. Prevention of the weeds is the best method. Pulling the weeds mechanically is only a temporary measure. The use of grass carp is considered a biological method that is an ongoing control process. Applying a chemical herbicide must be employed for specific weeds once those plants are accurately identified.
Prevent pond weeds by creating a buffer zone around the upper edge of the pond. The buffer zone should contain nutrient capturing plants. Keep a healthy turf above the pond’s runoff area to collect excessive nutrients and silt. Check with plant nursery suppliers so any introduced plants do not become invasive in and around the pond.
Keep all lawn fertilizers at least 20 feet from the water’s edge. Do not allow any runoff from septic systems or chicken coups to enter the pond. Most ponds will increase the vegetation in the body of water by excessive nutrient introduction such as lawn fertilizers and manure from livestock.
Introduce grass carp into the pond. The vegetation eating fish will aid in keeping some troublesome plants in check. General stocking rate is 10 to 15 fish per surface acre of the pond. More fish may be required if the pond is stocked with a predatory fish species such as bass.
Identify the actual weed species that is causing the problem. Take a sample of the weeds into your local agricultural extension service. Once the weed plant species is identified, the agricultural agent can then recommend a specific herbicide, and an application rate for the confined body of water. Follow all label and application direction rates on the herbicide container. Improper use of the herbicide chemical may cause a fish kill to the water.