What is this Plant in my Pond?

Learn how to eliminate aquatic plants that have suddenly overtaken your pond, and have become a problem either aesthetically or for the pond’s recreational use.
What is this Plant in my Pond? - Articles


The ponds in question range from just under an acre to several acres in size. Many of these pond plants tend to appear almost overnight with warm, sunny days fueling their growth. Rainfall washes nutrients into ponds, thus causing these "blooms" of aquatic vegetation. While having a healthy mix of several water plants in a pond is a good thing, having one or two plants taking over an entire pond, is not indicative of a healthy pond, nor is it aesthetically pleasing to the pond owner.

Some of the most commonly seen problem aquatic plants are as follows:

  • Filamentous Algae  - form long, thick, hair-like strands floating together in mats that become buoyed up to the surface of the water by trapped gasses. Ponds receiving water from surface runoff are especially susceptible to filamentous algae growth.
  • Duckweed  - tiny, free-floating plant with single dangling root.
  • Watermeal  - very small floating plant that resembles green seeds.
  • Naiad  - submerged plant with whorled or opposite leaves with toothed edges.
  • Coontail  - submerged, dense, feathery leaves resembling a raccoon tail, whirled around the stem, floats beneath the surface.
  • Eurasian Milfoil  - invasive, nonnative, nuisance plant with long stems, often reaching to the surface of a pond, with featherlike leaves in whorls of four or five around the stem.

Any plant can turn into a nuisance and control measures may be necessary. While most aquatic plants can be controlled by applying herbicides, the application requires a joint permit from the Fish and Boat Commission and the Department of Environmental Protection. Herbicides can be a quick fix, but if applied incorrectly, they can lead to unwanted killing of aquatic species like fish and frogs. There are some non-chemical alternatives such as barley straw to prevent algae, and triploid grass carp which eat some submerged plants, although these methods too must be researched to see if they are right for your pond. A pond water test is also recommended to determine the pH levels, dissolved oxygen, and bacteria levels - all important to consider depending on what the pond is being used for. Water test kits are available through your local county Extension office.