Water hyacinth

Water hyacinth (Eichhornia crassipes) is a State prohibited weed.

Namatjira Park closed from mid-July to treat hyacinth infestation

Namarjura Park, Clayton South-Water Hyacinth Infestation

  • A large infestation of water hyacinth has been detected at Namatjira Park in Clayton South.  Parts of the park will be closed from mid-July for 8 weeks to treat the infestation.
  • Treatment includes:
    • - Physical removal of plants
    • - Mechanical scraping of banks and base to remove seedbank
    • - Disposal of plants and seeds
  • No chemicals will be used as part of the removal.
  • The park will remain open during the works, but access will be restricted around the removal site.  The park entrances via Russ Street and Merlyn Avenue will be closed during the works while heavy machinery is being operated.  Alternative access is available via Simon Street, Newport Road and Springs Road.
  • Agriculture Victoria, Kingston City Council and Melbourne Water are working together to protect the park and restore it to a healthy state.  This will include returning retarding basin walls to pre-treatment dimensions, adding matting to prevent bank erosion and revegetating the banks.
  • Following treatment, Agriculture Victoria will continue to monitor the wetland and downstream channels for any signs of re-infestation.

Infestation of water hyacinth

If you find water hyacinth

If you think you may have seen water hyacinth, please contact us by:

Please do not attempt to treat or dispose of this weed yourself. We will treat, remove and dispose of water hyacinth safely, at no cost to the land owner.

Why you must report water hyacinth

Water hyacinth grows best in warm, nutrient rich, slow moving waterways but can also be found growing in soil on the waterway bank.

Water hyacinth is one of the world's worst aquatic weeds. It infests rivers, dams, lakes and irrigation channels on every continent except Antarctica. It devastates aquatic environments and costs billions of dollars every year in control costs and economic losses.

Water hyacinth is native to the Amazon basin in South America and was brought to Australia in the 1890s as an ornamental plant.

Duck walking on floating water hyacinth

Identifying water hyacinth

Water hyacinth is a floating water plant that can spread by daughter plants or seed. Water hyacinth plants have characteristic swollen stems with air filled tissue for buoyancy and large attractive mauve coloured flowers.

Bulbous stems contain air pockets, which help the plant to float. Stems can also be long and thin when the plants are crowded. Leaves are bright to dark green, smooth and glossy.

Water hyacinth flowers are mauve in colour, with a darker purple patch and yellow spot on the upper petal. A number of flowers will form on a single stalk in summer.

Water hyacinth has dark purple feathery roots.

Daughter plants grow from creeping stems that form roots at the nodes.

Leaves and bulbous stems of water hyacinthFlowers of water hyacinth

Roots of a water hyacinthCreeping stems of water hyacinth

This is water hyacinth.

Water hyacinth has two sorts of stems, a long thin one and a bulbous stem that is filled with a sponge like material to help it float.

It has bright green, glossy leaves and flowers in summer that are mauve in colour with a purple patch on the top petal with a yellow spot in the centre of the patch.

Water hyacinth has dark purple feathery roots and creeping stems that root at the node to form daughter plants.

Water hyacinth has been found in waterways, garden ponds and dams and for sale illegally at markets and online.

Additional information

In Victoria, Agriculture Victoria has been trying to raise awareness about water hyacinth and encouraging people to report and surrender any water hyacinth plants that they may have.

Resources have been developed to provide important information about water hyacinth in multiple languages to assist culturally and linguistically diverse people.

Have you seen this weed?

Page last updated: 03 Aug 2023