Duckweed

Duckweed (Lemna spp.) is a small, light green, free-floating, seed-bearing plant that has 1 to 3 leaves (fronds) that are about 1/16 inch in length. A single root (or root-hair) protrudes from each shoe-shaped frond. Duckweed often forms a layer on the surface that may cover an entire pond in calm weather. Heavy infestations can block sunlight needed for oxygen synthesis and fish productivity.

Duckweed floating on the surface of a pond.  

Management Options

Mechanical Options

Duckweed can be removed from the pond by booming or netting the vegetation off the surface.

Information on mechanical treatment of aquatic vegetation

Biological Options

Grass carp will consume duckweed, but they are not effective at controlling it.

Information on biological treatment of aquatic vegetation

Chemical Options

The active ingredients that have been successful in treating duckweed include Diquat (G), Flumioxazin (E), Fluridone (E), and Penoxsulam (E). E = excellent; G = good.

Information on chemical treatment of aquatic vegetation

Return to the non-rooted floating vegetation page