Keep your farm pond healthy; protect it from aquatic weeds


Farm ponds offer land owners many things - a source of water for wildlife and livestock, family recreation, and for some, a food source in the fish raised. To keep the farm pond healthy and to ensure water quality, land owners should follow certain management strategies.

Aquatic weeds can be a huge problem in some farm ponds and add to your frustration of trying to catch catfish, bass or perch. One important management strategy is to have your pond water tested to determine pH and alkalinity. Just as in a soil test, the pH of your farm pond is important to maintain. The Texas AgriLife Extension Service of Smith County can test farm pond water. Collect a pond sample in a clean water bottle and bring it to our office for testing.

Limestone can help raise the pH in your pond to optimum conditions. Liming the pond is important if the pH is below 6.5 and the total alkalinity is below 20 parts per million.

Another important management strategy is to properly identify and control unwanted aquatic weeds. Some aquatic weeds are OK. However, if left untreated, these weeds may cause problems. Aquatic weeds can be controlled manually, chemically and biologically. Remember to read and follow the label when applying aquatic herbicides. Weed control usually starts in the spring and continues through the summer months as needed. An important website for aquatic weed management is With water levels being low because of the drought, aquatic weed management is something you need to study if fish are important to the management of the pond.

Aquatic weeds fall into one of four categories: algaes, floating plants, submerged plants and emergent plants. Algea include filamentous algae, planktonic algae and muskgrass (chara). Algae are very primitive plants. Some algae are microscopic (Planktonic algae). Others are thin and stringy or hair-like (Filamentous algae), while still others are large and resemble higher plants but without true roots (chara).

Floating plants include duckweed, watermeal, water hyacinth, salvinia, and bladderwort to name a few. True floating plants are not attached to the bottom. Floating plants come in sizes from very small (Duckweed) to more than a foot in diameter (water hyacinth). Most have roots that hang into the water from the floating green portions.

Submerged plants include bushy pondweed, hydrilla, coontail, parrotfeather and watermilfoil. Submerged plants are rooted plants with most of their vegetative mass below the water surface, although some portions may stick above the water. One discerning characteristic of submerged plants is their flaccid or soft stems, which is why they do not usually rise above the water’s surface.

Emergent plants include cattail, lilies, giant reed, bulrush and pennywort. Emergent plants are rooted plants often along the shoreline that stand above the surface of the water (cattails). The stems of emergent plants are somewhat stiff or firm.

Control methods vary for these four weed categories. Proper pond construction is one important factor that can eliminate certain aquatic weed outbreaks. If the pond is designed too shallow around the edge, sunlight penetrates the bottom and weed populations explode. With water levels being down due to the drought, many people are renovating ponds making them deeper and removing silt that has washed into the ponds over the years. This will be helpful when ponds resume normal levels, helping to keep aquatic weed populations down.

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