Water Hyacinth


Water Hyacinth is a non-native perennial plant. It is free floating and grow up to 3 feet out of the water. Leaves are elliptical in shape and have a light blue to violet flower. The root system is very large and fibrous.

Other Names: Blue Shell, Shellflower

Mechanical Control

Water Hyacinth can be controlled by raking or skimming it off the pond's surface.

Chemical Control

Systemic herbicides, such as Shoreline Defense, will work to kill the root of the plant.

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.

For a fast-acting, selective herbicide that controls tough invasive and nuisance aquatic plants try KnockDown Defense.

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.