List of invasive plant species in New South Wales

NSW has over 340 weeds, though only one-third are considered noxious, which were purposefully introduced as garden and farmland plants, and thus had escaped.

An excess of $50 million of public money (half which come from state government) is currently being spent on weed control.

[2] Weeds are threat to the state's natural environment and would jeopardise many native plants and animals in NSW.

They would also effect the price of food, human condition (allergies and asthma), recreational activities and the economy of New South Wales.

These legal rules apply: Plants listed below are noxious weeds that should not to be sold in parts of New South Wales due to their invasive nature (most listed here are a 'Weed of National Significance') as they pose a threat to native fauna and flora, and are in the class 3 or 4 categories (a few are prohibited for purchase or propagation in some local government areas).

Limnobium laevigatum (frogbit) is declared ‘prohibited matter’ under the Biosecurity Act 2015 for its invasive and obstructive nature, therefore it's illegal to buy or sell this plant in NSW. [ 1 ]
A Class 1 weed, it is a criminal offense to import or plant Vachellia karroo .
A Class 2 weed, Salvinia molesta is regionally prohibited and should be eradicated from the land.
A Class 3 weed, land managers should minimise the risk of introducing or spreading Cestrum parqui .
A Class 4 weed, Anredera cordifolia must not be sold or imported into the state.
A Class 3, 4 and/or 5 weed (depending on the region), Lantana camara is a noxious weed that must not be sold or imported into the state.
Ipomoea cairica (Cairo morning glory) is a locally controlled weed (Class 4) and may not be sold or propagated in most areas of Sydney .
Initially an ornamental plant , Senna pendula has become a major pest in eastern Australia and is regarded a Class 4 weed.
A Class 4 weed, Olea europaea subsp. cuspidata (African olive) is not to be traded, carried, grown or released into the environment.
A Class 5 weed, Asparagus asparagoides (bridal creeper) is a restricted weed that may not be sold, bought or knowingly distributed throughout the state.
A Class 5 weed, Tamarix aphylla is a restricted weed that should not be sold or brought into the state.
A Class 4 weed, Opuntia monacantha or the common prickly pear has a prohibition on dealings .
A Class 3 weed, Honey locusts should be fully and continuously suppressed and destroyed in parts of the North Coast .
Although an ornamental plant , Rosa rubiginosa is not to be sold or propagated in numerous local authority areas, making it a Class 4 weed.
Solanum mauritianum is an environmental weed in the state, although it is not declared noxious.
Tropaeolum majus is a widespread non-noxious weed in the state.
Vinca major is a non-noxious environmental weed in the state.