Creeping Water Primrose floating pond weed

Ludwigia peploides is an emergent (shoreline) aquatic weed. Common names include creeping water primrose and primrose willow. Vegetation can grow both in shallow water, and along shorelines in wet areas.

Water primrose produces stems up to 3 feet tall. Stems can creep along the surface of the pond. Stems start along the shoreline and can stretch up to 15 feet across the surface of the pond! Leaves are oval to sword shaped with defined vein lines. Water primrose produces small yellow flowers with 5 petals each.

Water primrose is found in calm water and wet areas throughout the United States. It is native to south america and central america.

It most commonly spreads through stem fragmentation.

Water primrose is not a desired aquatic weed. It is labelled a noxious weed in some states. It's an aggressive spreader and out-competes desired native shoreline vegetation. The floating mats created by creeping water primrose provide an excellent breeding ground for mosquitos. The floating mats also reduce dissolved oxygen and lower pH levels.

There are currently no natural control methods for managing water primrose. Physical removal is not recommended because any fragments left behind will produce new growth. Roots and seeds will also produce new growth.

For mature weeds (flowering), spray vegetation directly with Clearcast, imazamox. This is absorbed down to the roots.  

Glyphosate 5.4 is a liquid aquatic herbicide that will work on creeping primrose that are along shorelines and above the water surface. Spray glyphosate mixed with surfactant directly on primrose to kill vegetation to the roots.

Propeller is another treatment option for treating larger areas. Propeller's active ingredient is flumioxazin and comes in granular form. The granules are mixed with water in tank sprayer and sprayed in areas where vegetation is actively growing.