Authored by: Sarah Frances McNair Wesley Gerrin Dr. James Shelton Springtime in Georgia may be delightful, but for pond owners, it often brings about confusion and frustration as their ponds undergo seasonal changes. One such change is the appearance of plants and other organic materials on the surface of the pond. Larger floating plants, such as water lilies, are easy to identify from a distance. Smaller plants and organic materials are harder to identify and must be viewed up close. This includes Duckweed, Watermeal, algae, and pollen, all of which are small, floating organisms that could be mistaken for one another. Duckweed (top), filamentous algae (middle), and pollen (bottom), as seen on the surface of a pond. Duckweed (Lemna sp.) and Watermeal (Wolffia sp.) are two small floating plants that often grow together in ponds. Algae are plant-like organisms that photosynthesize and live throughout the pond. Algae can be single-celled, or grow in clumps or filaments. Pollen is a powdery substance produced by flower plants. When viewed from a distance on the surface of a pond, these four are lookalikes. It is important to correctly identify all aquatic plants before attempting to apply herbicides or any other treatment. In nearly all cases this involves removing them from the water and taking up-close photos. Duckweed (top), filamentous algae (middle), and pollen (bottom), as seen on the surface of a pond. Duckweed and Watermeal can be distinguished by their size differences. Both are small and circular; however, Watermeal is much smaller and does not have roots extending from the fronds. Filamentous algae, when removed from the water, is clumped or stringy and often has an unpleasant texture and smell. Pollen will retain its powdery appearance when removed from the water and is typically more yellow in color than Duckweed, Watermeal, or algae. Like algae, pollen will develop an unpleasant odor as it decomposes. Once you have identified what is in your pond, you can then move forward with developing and implementing a management plan. Work with your local Extension office or pond management company to determine what herbicides, algaecides, biological control, or other control methodologies are appropriate for your pond. In the case of pollen, it is best to wait it out, as the surrounding flowering plants will eventually go out of season.
