Spatterdock is a perennial plant that has leaves roughly heart shaped. The leaves can be as large as 8-16 inches long by 10 inches wide. Flowers are yellow and are either at the surface or stand above it.

Other Names: Cow Lily

Mechanical Control

Spatterdock can be cut or the rhizomes can be dug up. It will be difficult to control this way because it will regrow from seeds and remaining rhizomes.

Chemical Control

There are several options to control Spatterdock in ponds.

  1. Use a season long herbicide such as Airmax WipeOut. One treatment treats the entire body of water for Spatterdock and many other common pond weeds for the season.
  2. Use systemic herbicides, such as Shoreline Defense, will work to kill the root of the plant.
  3. Broad spectrum contact herbicides, such as Ultra PondWeed Defense, will quickly kill any part of the plant it touches but multiple treatments may be needed throughout the season.
  4. Try KnockDown Defense, a fast and selective herbicide that controls tough invasive and nuisance aquatic plants.

Chemical Application Best Practices

Anytime you use chemicals treat weeds and algae, please keep in mind the following:

  • Treat your pond in sections. Treat only half the pond's surface at a time. During hot weather or when treating heavy growth, it is important to treat no more than 1/4 of your pond at a time and wait the full 14 days before re-applying. This helps lower the risk of fish loss during hot weather or when treating heavy growth.
  • Once the weeds have browned, use a rake to remove as much dead material as possible. This prevents an accumulation of dead plant material and muck.
  • Take a proactive approach to pond management. Use PondClear, MuckAway and Pond Dye to keep your pond looking great. For more information, see our article on the Airmax Ecosystem.

Ask an Expert

If you are unable to identify your pond weed(s) using our Weed ID Guide, follow this article to email us a photo.