Watermilfoil

Species: Myriophyllum salsugineum

weed identification

common name
Watermilfoil
description

Watermilfoil is a native submerged plant, its leaves form whorls along the length of its stems. The plant ranges from green to purple in colour. It’s distinguishable from other watermilfoil species by its rigid leaves when outside of the water and its slightly longer, 2mm long fruit.

habitat

Commonly found in lakes and slow-flowing water bodies, it tolerates slightly salty water.

distribution
NSW, SA, TAS, VIC, WA
native or exotic?
Native
reproduction

Watermilfoil can reproduce by plant fragments but they may be very slow to take root. Where as seeds readily germinate in clear, shallow water.

dispersal

It is easily spread from boat damage by water currents.

benefits

It provides important habitat for birds, frogs and other native fauna. It can also act as a buffer from other surrounding catchment areas.

What does Watermilfoil look like?

Use these images below to help you decide whether you are dealing with Watermilfoil.

Disadvantages of Watermilfoil

Dense infestations of Watermilfoil can cause significant problems such as:

  • Potential to obstruct water flow, block pumps and filters

  • May dominant water body, inhibiting growth of other aquatic plants

  • Restricts water-based recreation

treatment

AQ200 Aquatic Herbicide – Chemical Herbicide designed to kill submerged weeds quickly. Use on mild to severe infestations.

Aquatic Weed Rake and Razor combo – DIY physical removal. Ideal for mild infestations, sensitive water bodies or to aid herbicide treatment

Aquatic Harvesting (Mobitrac) – Large amphibious machine that clears submerged aquatic weeds. Book this service for severe infestations or for larger water bodies.

prevention options

Aquatic Blue – Blue dye that may reduce temperature of the water body by reducing UV light penetration. This may then increase oxygen saturation.

Aerating Fountains – Reduces the severity and likelihood of aquatic weed infestations. Use in any body of water.