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Aquatic Herbicide for Watercress

Watercress (Nasturtium officinale), also referred to as American cress, is a native European herb from the mustard family. The plant grows in slow-flowing streams and wet landscape areas. Watercress has an invasive nature and often requires the use of an aquatic herbicide to bring it under control.
  1. Watercress Description

    • The watercress plant is succulent with a spreading root system. Plants mature to create 12-inch mounds. The dark green, opposite foliage is ovate in shape and grows on hollow stems. Watercress blooms with very small, white flowers during summer. The flowers are followed by slender seedpods that split to reveal seeds upon ripening. New plants are created by the germination of seeds in the fall.

    Herbicide Recommendation

    • Watercress can be effectively controlled with the use of the aquatic herbicide endothall. The herbicide is sold under different trade names.

    Herbicide Description

    • Products containing endothall are classified as general-use pesticides. The chemical belongs to the dicarboxylic acid group and works as a selective contact herbicide. Endothall controls a wide variety of aquatic weeds such as watercress, milfoil, pondweed and algae. The herbicide is also used for annual grasses and broadleaf weeds on land.