Duckweed Plants

Description

• Duckweed is among the smallest known flowering plants on earth. The very tiny flowers are rarely seen, and the plant reproduces through budding and plant fragments. The plant occurs singly or in groups with elliptical-to-round leaves measuring less than ¼ inch in diameter. A thin strand or root grows from the underside.. Certain species are about 1/8 inch wide. Each plant produces a daughter bud every one or two days. Under optimal growth conditions and warm weather, a single plant produces nearly 17,500 daughter plants.

Favorable Conditions

• The plant thrives on still or slow-moving water and is usually seen on ponds located in shaded, moist woods. Water with excessive levels of nutrients, especially phosphorus and nitrogen, supports aggressive growth. This often occurs in water bodies that are receiving water from leaking septic fields, feed lots or agricultural runoff. Home ponds getting runoff from landscape fertilizer are also prone to duckweed infestation. Water with years of organic sediments collected at the bottom also encourages duckweed growth. Ducks, geese or other birds frequently transfer plants from one place to another.

Cultural Control

• Remove duckweed from water surface with a fishing net or a pumping device. Dispose the plants carefully so they are not carried back to the water by air. Introduce duckweed-eating fish, such as koi or grass carp, into the water. This is most effective when done at the earliest sign of plant growth. Reducing fertilizer runoff lowers the nutrient level. In smaller ponds, keep the base clear of sediments from dead plants and other material.

Chemical Control

• Some chemicals help control duckweed growth. These include products containing diquat or fluridone. Repeat applications are often necessary for complete elimination. Make certain that all duckweed growth is finished in water as any surviving plant reproduce rapidly. Combining these chemicals with copper-based compounds increases their effectiveness.