Control Water Primrose

Floating primrose is a very common plant, most easily identifiable by its five-petal yellow flowers and its reddish stems. Other varieties of primrose can look similar, and managing them is the same. The following options can be considered for how to control floating primrose.

Click here to read more about identifying this plant.

Manual/Mechanical Control:

If you are considering how to remove primrose, physically cutting this plant and digging up the roots can be a somewhat effective method of control. However, physical control can be difficult. Primrose can re-grow from any roots left behind or seeds remaining in the water.

Herbicide Control:

There are a few options for how to kill primrose that offer great or some control.

1. Cattail and Water Lily Control (Imox + surfactant) (for ponds or lakes) – liquids that are mixed and diluted with water and sprayed directly on the plants.
2. Liquid 2, 4-D (for ponds or lakes) – liquid that is diluted with water and sprayed directly on and over the plants. Most effective on treatment areas larger than a half acre, this allows longer contact exposure time.
3. Semera or Flumigard + surfactant (for ponds or lakes) – granules that are dissolved and mixed or liquids that are mixed and diluted with water and sprayed on the plants (early morning is best), fast acting. This will give some control.

Treatment Tips:

When treating primrose,

• With Imox or other systemic herbicides, treatment is most effective when the plants are mature or close to full grown. This allows for more plant surface to spray enough mixture on.
  • Treat in late summer to early fall to get better kill of the root systems. At this time, plants are pulling energy into their roots to store for the winter.
• With 2, 4-D, treat when the plants are established and actively growing. 2, 4-D options generally do not impact root systems with early season treatment. May require multiple treatments in the spring or summer to completely control primrose down to the roots.