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Five Facts About Duckweed

Duckweed is a free-floating water plant that spreads rapidly. It is considered a nuisance plant in many areas of the country. They are the world's smallest aquatic plant.


Duckweed has one to three light-green leaves that measure 1/16 to 1/8 of an inch across. Hairlike roots are attached to the leaves. Common duckweed (Lemna minor) is smaller than giant duckweed (Spirodela polyrhiza). Watermeal is the smallest of all duckweed.


Duckweed forms dense colonies in nutrient-rich stagnant water. It does not grow in moving water, but prefers still water.


A duckweed plant produces a daughter bud about once a day. With ideal growing conditions, the original plant and its daughter buds can produce as many as 17,500 plants in two weeks.


A duckweed colony blocks the sunlight, which results in the decline of underwater plants. It also depletes the oxygen in the water, which causes fish to die.


Duckweed is difficult to control. Reduce the runoff of nutrients into bodies of water and use bubble aeration to inhibit the growth of duckweed. Duckweed can be removed manually or controlled with chemicals. Koi, goldfish and grass carp eat duckweed, but grass carp will eat other plants first. Although ducks eat duckweed, they also spread it when it sticks to their feathers.

Facts On Duckweed

Have you ever looked out at a pond and noticed the surface was covered in something green? Don't mistake this for fronds, algae or toxic waste. It may just be duckweed, tiny oval-shaped plants on the water's surface. These plants can cause some problems, but they also have benefits. Duckweed mainly grows in warm, wet environments around the world, either in shade or direct sunlight. These bodies of water contain high levels of nutrients such as phosphorus or nitrogen. It can be placed in freshwater aquariums. Duckweed can multiply at an incredibly fast rate. To control the growth of duckweed, reduce the flow of nutrients into the water or remove the duckweed at repeated intervals. Duckweed can be used to help purify water by controlling algae growth and converting waste and sewage water into treated water and biomass (duckweed leaves and roots).

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