Priority weeds
We work hard to keep our environment safe and as free from weeds as possible, so everyone can enjoy the incredible natural environment that Port Stephens has to offer.
African olive
(Olea europaea - subsp. cuspidata)
African olive is an invasive weed that is taking over properties across the Hunter and harbouring pests like foxes, rabbits and myna birds. Find out how you can help stop the spread of this nasty weed:
- check out our African Olive fact sheet (PDF 518 KB)
- visit WeedWise website.
Highly invasive weed in dry woodlands, riverine, coastal headlands and dunes. It out-competes native vegetation and prevents regeneration. African Olives aggressively invade cleared land, reducing the value and productivity of properties. They provide poor habitat for native animals and good habitat for feral birds such as Indian Mynas. If not controlled, the plant will take over large areas forming huge, dense monocultures of African Olive.
Seedlings can be hand pulled if all the roots can be removed. Beds of dense seedlings can be sprayed. More established plants will need to be cut and painted with herbicide (Roundup or Garlon). Apply herbicide mixture to cut surface as quickly as possible. For larger plants, inject herbicide into the stem or basal bark spray. The wood of African Olives is very hard, so ensure drilling or chiselling gets well into the stem.
Seeds are spread by birds and foxes. There is an current, significant infestation occuring in Hinton, Wallalong, Osterley and Brandy Hill.
Chinese violet
(Asystasia gangetica subspecies micrantha)
Chinese Violet is a national priority weed and is the subject of a Council eradication project. Almost all recorded infestations in Australia occur in Port Stephens. For more information:
- check out our Chinese Violet fact sheet (PDF 852KB)
- visit WeedWise website.
Cats Claw Creeper
(Dolichandra unguis-cati)
Cat's claw creeper has escaped gardens to become a major weed of native forests and riparian areas in eastern Australia.
It competes with native plants by forming a dense above-ground mat and numerous underground reproductive tubers.
Its climbing woody stems (lianas) cling to tree trunks, enabling it to grow into the forest canopy. In native rainforests it can overtop and kill mature trees, opening up the canopy for light-loving weeds.
Dense infestations of cat's claw creeper are very difficult to control due to its numerous lianas, abundant seed and ability to resprout from the tubers, sometimes for years.
Weeding should proceed gradually as creation of large gaps can lead to further weed invasion. Follow up is essential.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Even seedlings and small plants have tubers that are difficult to dig out.
Cats claw creeper can be most effectively controlled by employing the 'cut stump' technique and applying a registered herbicide such as, Picloram 44.7 g/kg + Aminopyralid 4.47 g/L eg Vigilant II ®. Always refer to the label prior to use.
Seed pods mature in late summer to autumn and seeds start dropping from the vines in late May. Most seeds fall in July and August. Seed viability is low but seed production is high and some seeds produce multiple seedlings. The winged seeds can be blown in the wind and spread by water along streams and rivers. Established plants can reproduce from tubers and stems. The tubers can be spread in flood waters or by machinery if the soil is disturbed.
Photos courtesy of the NSW Department of Primary Industries.
Pampas grass
(Cortaderia species)
While it is not yet a major weed in NSW, our efforts are focused on ensuring this weed does not take hold.
Once established, the plant is very competitive, restricting the establishment of native trees, and can become a fire hazard and harbour vermin.
Pampas grass is of greatest potential weed significance to forestry operations. However, it has not yet become a major problem in NSW forests, as such preventative measures are essential.
It has a root system up to 3.5m deep. The tussock produces large quantities of flammable material. It is very competitive with native plants.
Pampas grass is readily grazed by stock when it is young, before it becomes too abrasive. This prevents the development of flowers and seed set.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Residents can employ the use of a registered herbicide in order to control this weed, such as; Glyphosate 360 g/L eg Roundup®. Always refer to the label prior to use.
In many cases, garden plants are the seed source for infestations. Individual plants have the ability to produce vast quantities of windborne seed — up to 100,000 per flower head, which can infest areas within a 25km radius.
Paterson's Curse
(Echium Plantagineum)
Reduces Pasture Productivity and is toxic to livestock.
Can degrade the natural environment, comprising habitat values by crowding out and suppressing native vegetation.
Decreases value of hay and grain contaminated with it.
Affects human health. Some people are allergic to the pollen and the rough hairy texture of the leaves and stems causes skin irritation in people having close contact with the plant.
Preventing Paterson’s curse from spreading to uninfested areas should be given a high priority. Once it becomes established in an area it is extremely difficult to eradicate. Paterson’s curse spreads only through the movement of seeds; therefore methods which prevent seed moving to uninfested areas should be employed.
It is a prolific seeder that can produce more than 5000 seeds per plant per year.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Residents can employ the use of a registered herbicide in order to control this weed, such as; Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L eg Grazon Extra® and Dicamba 500 g/L eg Kamba® 500. Always refer to the label prior to use.
Paterson's curse reproduces by seed. It is commonly spread via contaminated hay and grain, livestock droppings and machinery. It is a prolific seeder that can produce more than 5000 seeds per plant per year. Large quantities of seeds may accumulate in the soil over several years. For example, a seedbank of up to 30 000 seeds per square metre has been reported. Seeds may remain dormant in the soil for up to five years.
Photos courtesy of the NSW Department of Primary Industries.
Glory Lily
(Gloriosa superba)
Can form dense understorey carpets in dune systems along the coast, competing strongly with native flora.
Glory lily also compromises bitou bush control programs because, once the bitou bush is removed, glory lily can form a dense understorey.
All parts of the glory lily are highly toxic and has been responsible for the poisoning of both humans and livestock.
Dumping garden waste in bushland or allowing these garden plants to spread out of control in gardens close to natural bushland areas, creates a major threat of further infestations.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Residents can employ the use of a registered herbicide in order to control this weed, such as; Glyphosate 360 g/L eg Roundup® and Glyphosate 360 g/L with Metsulfuron-methyl 600 g/kg (Various products). Always refer to the label prior to use.
Each plant can produce over 1000 seeds. The seeds remain in the soil over winter and germinate in spring. Seeds may be spread by birds. Glory lily also grows from tubers and rhizome fragments. People dumping garden waste is the main way that plants have spread to new areas.
Photos courtesy of the NSW Department of Primary Industries.
Prickly Pear and Tiger Pear
(Cylindropuntia and Opuntia species)
There are many different Prickly pear species — in Port Stephens, our focus is on the Opuntia species. This Weed of National Significance must not be sold in NSW.
Spreads by seed or vegetatively by segments which root where they contact the ground. The plant invaded large areas of northern NSW and central Queensland in the early 1900s and was infesting some 25,000,000 hectares.
Currently only minor occurrence exist within the Port Stephens LGA, as such preventative measures are essential.
Common pest pear is largely controlled by the biological control cactoblastis, Cactoblastis cactorum. In areas where cactoblastis cannot complete 2 generations per year, it can be controlled by the biological control cochineal, Dactylopius opuntiae.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Residents can employ the use of a registered herbicide in order to control this weed, such as; Triclopyr 600 g/L eg Garlon® 600 and Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L eg Grazon Extra®. Always refer to the label prior to use.
Most spread in Australia has been by humans — either as garden plants and hedges — or through dumping in rubbish tips or bushland.
Vegetative spread is the most common form of dispersal. This can happen year round when segments, immature fruit or flowers detach and make ground contact. Segments can easily spread by attaching to clothing, footwear or the fur of animals.
Hygrophila
(Hygrophila costata)
Hygrophila is a highly invasive aquatic weed. It grows up to 1.5 m high in shallow water, forming mats of dense growth around the margins of freshwater lakes, rivers and watercourses where it can dominate and out-compete other vegetation.
Dense infestations are likely to displace native flora and fauna by destroying their natural habitat.
It can also interfere with recreational activities such as boating and access to the water’s edge.
Your local council weeds officer will assist with identification, control information and removal of this weed.
Residents can employ the use of a registered herbicide in order to control this weed, such as Glyphosate 360 g/L (Only products registered for aquatic use, eg Roundup Biactive®). Always refer to the label prior to use.
Control of hygrophila is very difficult as new infestations can form from any remaining pieces of the plant.
Reproduction is by either seed or stem fragments. Spread occurs when seeds and plant fragments attach to animals, machinery or watercraft, or are dispersed by wind or water. As such good hygiene practices, such as washing down boats before leaving the area, play an essential role in controlling this weed.
Plants have been spread by people dumping aquarium or pond plants in waterways. Seed is also distributed by water, animals, wind and watercraft.
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.
Photos courtesy of the NSW Department of Primary Industries.
Mother of millions
(Bryphyllum species)
Mother of millions is a drought hardy succulent garden plant. It rapidly produces tiny plant-lets that quickly form new colonies. All species and hybrids of Bryophyllum are declared noxious weeds.
As the name suggests, mother of millions reproduces rapidly, producing hundreds of tiny plantlets which quickly form new colonies. It is adapted to dry conditions and can survive long periods of drought.
Is toxic to humans and household pets with dogs being particularly susceptible. It is unlikely that humans or pets would eat enough plant material to become poisoned. However, because mother of millions can be found in many gardens, the likelihood of human or pet poisoning is increased.
Your local council weeds officer will assist with identification, control information and removal of this weed
Preventing the spread of mother of millions is the best control measure. Regularly check for it in winter when the plants are in flower and are easier to see. If found remove immediately using a combination of control methods including hand removal and herbicide application. Hand removed plants should be stored in black plastic bags until decayed or buried.
Residents can employ the use of a registered herbicide in order to control this weed, such as Fluroxypyr 333 g/L eg Starane™ Advanced or Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L eg Grazon Extra®. Always refer to the label prior to use. Always add a wetting agent.
As the name suggests, Mother of millions reproduces rapidly — producing hundreds of tiny plantlets which quickly form new colonies.
Water Hyacinth
(Eichhornia crassipes)
Water hyacinths are one of the world’s worst aquatic weeds. It infests rivers, dams, lakes and irrigation channels on every continent. It devastates aquatic environments and costs billions of dollars every year in control costs and economic losses.
It forms dense, impenetrable mats over the water surface, destroying natural wetlands, restricting recreational use of waterways, reducing aesthetic values of waterways, reducing water quality and changes the temperature, pH and oxygen levels of water.
Your local council weeds officer will assist with identification, control information and removal of this weed
Most spread can be attributed to human activity such as the deliberate planting of water hyacinth in ornamental ponds or dams. Water hyacinth can also be spread by contaminated boating equipment.
Early detection and rapid response offer the greatest likelihood of successful control and the opportunity for eradication. It is essential that any new infestations are controlled as soon as possible. In NSW, a number of herbicides are registered for the control of water hyacinth such as Glyphosate 360 g/L eg Roundup Biactive® or Metsulfuron-methyl 600 g/kg eg Brush-off®. Always refer to the label prior to use.
The seeds are released from the capsule underwater. Each capsule has between 40 and 300 seeds. The seeds either sink or accumulate in the floating plant mat. Seed remains viable for up to 20 years in mud or soil. Seeds can be moved to new locations by water flows or via mud stuck to birds, machinery and footwear.
Water hyacinth infestations increase most rapidly by producing new daughter plants. Each plant can produce 2-4 daughter plants. Most of these are produced in spring to summer. During high water flows and flooding, plant masses can break up and move to new locations.
Photos courtesy of the NSW Department of Primary Industries.
Water Lettuce
(Pistia stratiotes)
Tourism and recreation are affected when water lettuce limits recreational activities, reduces aesthetic values and increases mosquito populations.
Water lettuce can quickly form mats over the water surface, destroying natural ecosystems and blocking irrigation equipment.
Rivers, wetlands, lakes, reservoirs and other slow-moving streams are most affected by this species. Water lettuce can survive for long periods on muddy banks or in other damp locations such as roadside culverts.
To manage water lettuce you should contact the Invasive Species team if you see an infestation so they can help control it. For small isolated infestations, these can be physically removed and bagged, however It's important to take care to prevent the spread of plant parts when moving this species.
Herbicide treatments should be considered when managing large infestations, utilizing a registered herbicide. Contact the Invasive Species team for suggestions on herbicide, as the use of certain products is determined by the specific situation that the plant occurs.
The seeds germinate in early summer once temperatures rise above 20°C. Then the new seedlings float to the surface. The buoyant seedlings can move further downstream. Seeds create ongoing problems in infested areas. Water lettuce grows all year round.
Each plant produces daughter plants. Each daughter plant then produces its own daughter plants, forming dense mats. When broken up, each plant, or even pieces of plants, can start to grow a new mat. Water lettuce used to be sold at nurseries or pet shops as ‘water rose’. It’s still found in some ponds and dams. Floods can spread these plants to new areas.
Photos courtesy of the NSW Department of Primary Industries.