Hygrophila is an upright plant that grows over a metre tall in shallow water. It forms dense mats along the edges of creeks and water bodies and outcompetes native plants.
Hygrophila is a water weed that:
Hygrophila can grow in shallow water rooted in the mud, extend out over the water from the banks and grow as floating mats. It usually grows to 1.5 m high but can reach up to 2.5 m high when it scrambles over other vegetation. It grows quickly in warm weather.
Hygrophila looks like:
Hygrophila usually grows in subtropical coastal regions. It is invasive in the far north coast, central coast and Greater Sydney regions of NSW.
Hygrophila is native to Central and South America and has naturalised in many tropical and subtropical areas around the world.
In NSW, hygrophila grows in shallow freshwater, along creek banks and in shallow wetlands. It is often found at disturbed sites where native vegetation has been removed and the water has very high nutrient levels.
Plants have been spread by people dumping aquarium or pond plants in waterways.
Water, animals, wind and watercraft can spread the seed.
Plants can grow from cuttings or severed leaves. Leaves can sprout roots if they are left floating on the water’s surface. Stem fragments sprout new roots when they come in contact with the soil.
Water, animals, machinery and watercraft can spread plant parts.
Csurhes, S. (2008). Glush weed. Hygrophila costata. Plant pest risk assessment. Queensland Department of Primary Industries and Fisheries.
Grantly, J., McPherson, F., & Petroeschevsky, A. (2009). Recognising Water Weeds: Plant Identification Guide. NSW Industry & Investment
PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 8 September 2020 from: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Hygrophila~costata
Sainty, G. R., & Jacobs, S. W. (2003). Waterplants in Australia (No. Ed. 4). Sainty and Associates Pty Ltd.
Successful weed control relies on follow up after the initial efforts. This means regularly looking for any new plants or plant fragments and controlling them.. Using a combination of control methods is usually more successful.
Contact your local council weeds officer for help identifying hygrophila, and advice on controlling it.
Collect and dispose of all plant fragments when physically removing hygrophila. Ask your local council for advice on how to dispose of this weed.
See Using herbicides for more information.
PERMIT 14729 Expires 30/06/2024
Metsulfuron-methyl 600 g/kg
(Various products)
Rate: 5–10 g per 100 L of water
Comments: Minimise off target damage and water pollution by spraying towards the bank. Do not apply more than 3 times a year.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High
PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L
(Only products registered for aquatic use)
Rate: 100 mL in 10 L of Water
Comments: Spot spray application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate
The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
Area | Duty |
---|---|
All of NSW | General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
Central West |
Regional Recommended Measure* (for Regional Priority - Prevention)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
Greater Sydney |
Regional Recommended Measure* (for Regional Priority - Eradication)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
Hunter |
Regional Recommended Measure* (for Regional Priority - Eradication)
Notify local control authority if found. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. |
North Coast
Exclusion (eradication) zone: Bellingen Shire LGA, Clarence Valley LGA, Coffs Harbour City LGA, Kempsey Shire LGA, Lord Howe Island, Port Macquarie-Hastings LGA, Nambucca Valley LGA. Core infestation (containment) zone: Ballina Shire LGA, Byron Shire LGA, Kyogle Shire LGA, Lismore City LGA, Richmond Valley LGA, Tweed Shire LGA. |
Regional Recommended Measure* (for Regional Priority - Containment)
Whole of region: Land managers should mitigate the risk of the plant being introduced to their land. A person should not buy, sell, move, carry or release the plant into the environment. Exclusion zone: Notify local control authority if found. Land managers should eradicate the plant from the land and keep the land free of the plant. Core infestation: Land managers should mitigate spread of the plant from their land. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value. |
North West |
Regional Recommended Measure* (for Regional Priority - Prevention)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here |
Reviewed 2023