Canadian pond weed: declared pest

Page last updated: Monday, 11 May 2020 - 12:59pm

Please note: This content may be out of date and is currently under review.

Canadian pond weed (Elodea canadensis) is a declared pest in Western Australia (WA). This article describes the nature of the plant with links to requirements land owners/occupiers must adhere to and pest control methods.

Form: aquatic

Status: not known to be present in WA, if found please report

Native to temperate regions of North America. In Australia it reproduces vegetatively, only forming male flowering plants.


A submerged aquatic perennial freshwater herb, usually firmly rooted to the bottom mud and producing a thick green mat below the water surface.

Stems: Short thread like stolons giving rise to slender vertical stems to three metres long. Joints are brittle

Leaves: Dark green, formed at intervals of 3–25 millimetres along the stem. Lower leaves opposite, oval in outline. Upper leaves in whorls of three, each 6–12 millimetres long, rarely up to 17 millimetres, about one to five millimetres wide, usually with forward pointing teeth on the margins.

Flowers: White, with three sepals and petals. Flowers are solitary forming in the axils of the leaves and growing towards the surface on threadlike stalks about 30 centimetres long.

Roots: Filamentous rising from the nodes along the stolons.

Agriculture and economic impact

An environmental weed that  invades still or slow-moving freshwater environments and thrives in temperate regions. Infestations outcompete native aquatic plants, modifying aquatic flora assemblages and habitats.

Declared pest category

The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Search for Canadian pond weed in WAOL using the scientyific name Elodea canadensis.

Requirements for land owners/occupiers and other persons

Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.

Search > detect > report

MyPestGuide™ Reporter
via app or online
(Select 'Send report to MyWeedWatcher' from menu)

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080

Control method

Report the presence of this organism before undertaking a control measure. Control methods for this declared plant can be found through the Canadian pond weed control link.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080
Technical support - MyPestGuide®