Marine and Freshwater Pests

One of the world's worst weeds, alligator weed can grow in both aquatic and terrestrial environments. Once established it is extremely hard to eradicate. It has been recorded at several locations in Hornsby Shire, and could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. It is illegal to import into the State or sell this plant. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid alligator weed from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland, watercourses, dams, or plant fragments down stormwater drains.

For information on the identification and control of alligator weed, visit https://weeds.dpi.nsw.gov.au/Weeds/AlligatorWeed

Frogbit is a floating water weed that grows very quickly, forming dense mats over water bodies. In Hornsby Shire it could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Frogbit is PROHIBITED MATTER. It is illegal to grow, keep, import, sell or move this plant. You must notify the NSW Department of Primary Industries as soon as you become aware or suspect the presence of this plant. Failure to notify is also illegal. Do not attempt to treat or dispose of the plant yourself. Call the NSW DPI Biosecurity Helpline 1800 680 244. Check your ponds, aquariums, fish tanks, water features, dams, and waterways for this plant.

For information on the identification of frogbit, visit https://weeds.dpi.nsw.gov.au/Weeds/Frogbit

Kidney leaf mud plantain is a water weed capable of forming dense mats in shallow freshwater and on damp soil at the water’s edge. In Hornsby Shire it could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid kidney leaf mud plantain from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland, watercourses, dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of kidney leaf mud plantain, visit https://weeds.dpi.nsw.gov.au/Weeds/KidneyleafMudPlantain

An aquatic shrub with yellow flowers, long-leaf willow primrose forms dense stands in slow-moving or still water. It has been recorded at several locations within Hornsby Shire, including along dam edges, roadside drainage ditches and creek lines, and as a weed in nursery stock. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid long-leaf willow primrose from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland, watercourses, dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of long-leaf willow primrose, visit https://weeds.dpi.nsw.gov.au/Weeds/LongleafWillowPrimrose

Ludwigia is an invasive shrub that thrives in moist, wetland areas and has a dramatic impact on aquatic environments. It has been recorded at several locations within Hornsby Shire, especially around dams and along creek lines. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid ludwigia from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland, watercourses, dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of Ludwigia, visit https://weeds.dpi.nsw.gov.au/Weeds/Ludwigia

Parrot's feather is a common weed in coastal waterways of eastern Australia. It has been recorded at several locations in Hornsby Shire, and could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid parrot’s feather from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading plant fragments down stormwater drains.

For information on the identification and control of parrot's feather, visit https://weeds.dpi.nsw.gov.au/Weeds/ParrotsFeather

Red ludwigia is a creeping aquatic plant with red stems that can dominate waterways and outcompete native plants. It has been recorded in Hornsby Shire, and could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid red ludwigia from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of red ludwigia, visit https://weeds.dpi.nsw.gov.au/Weeds/RedLudwigia

Sagittaria is an aquatic weed, capable of aggressive growth and rapid spread. It has been recorded in several dams and creek within Hornsby Shire. It is illegal to import into the State or sell this plant. Notify Council if you see sagittaria in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid this plant from being introduced onto to your land. If you find sagittaria on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of sagittaria, visit https://weeds.dpi.nsw.gov.au/Weeds/Sagittaria

Salvinia is a floating water weed that forms dense mats and can quickly take over waterways. It has been recorded in Hornsby Shire, and could be found in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. It is illegal to import into the State or sell this plant. Notify Council if you see salvinia in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid this plant from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading plant fragments down stormwater drains.

For information on the identification and control of salvinia, visit https://weeds.dpi.nsw.gov.au/Weeds/Salvinia

Senegal is a hardy plant with a rapid growth rate, found on the banks of watercourses and in shallow water. Scattered populations have been recorded in the Sydney region and it may be present in Hornsby Shire in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid Senegal tea plant from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of Senegal tea plant, visit https://weeds.dpi.nsw.gov.au/Weeds/SenegalTeaPlant

Water hyacinth is a floating water weed with blue flowers. It forms dense mats that reduce water quality and affect native aquatic life. It has been recorded in dams and ponds within Hornsby Shire, but could also occur in aquariums, fish tanks, water features, and waterways, dumped in bushland or roadsides, or being sold online. It is illegal to import into the State or sell this plant. Notify Council if you see water hyacinth in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid this plant from being introduced onto to your land. If you find water hyacinth on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of water hyacinth, visit https://weeds.dpi.nsw.gov.au/Weeds/WaterHyacinth

Water lettuce is a free-floating weed that spreads rapidly and forms dense mats over water bodies. Scattered populations have been recorded in the Sydney region and it may be present in Hornsby Shire in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid water lettuce from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of water lettuce, visit https://weeds.dpi.nsw.gov.au/Weeds/WaterLettuce

Water poppy is an aquatic plant that can form dense infestations that choke waterways. It has been recorded being sold in Hornsby Shire and could occur in aquariums, fish tanks, water features, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see water hyacinth in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid this plant from being introduced onto to your land. If you find water poppy on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of water poppy, visit https://weeds.dpi.nsw.gov.au/Weeds/WaterPoppy

With large floating leaves and bright yellow flowers, yellow waterlily forms dense infestations on waterways that reduce water quality and outcompete native plants. Scattered populations have been recorded in the Sydney region and it may be present in Hornsby Shire in ponds, aquariums, fish tanks, water features, dams, and waterways, dumped in bushland or roadsides, or being sold online. Notify Council if you see this plant in Hornsby Shire or see evidence of it being traded (including online), carried, grown, or released into the environment. Try to avoid yellow waterlily from being introduced onto to your land. If you find it on your property, prevent it from spreading from your land where possible, especially into bushland areas, watercourses, and dams, or spreading seeds or plant fragments down stormwater drains.

For information on the identification and control of yellow waterlily, visit https://weeds.dpi.nsw.gov.au/Weeds/YellowWaterlily