About noxious weeds

The term ‘noxious weeds’ indicates weeds that are such a serious threat to agriculture or the environment that governments require their eradication.

Different governments (including Councils) have different lists of noxious weeds, depending on local conditions and impacts. Noxious weeds listed for the Blue Mountains can be found on the Council website.

Noxious weeds are classified, from 1 to 5, depending on the authority mandating their control, the type of threat they pose the sort of action required to remove them and other factors.

Some weeds pose such a pervasive threat that they are listed nationally as ‘Weeds of National Significance’, or WoNS.

Here is the list of noxious weed classes and their definitions, along with Weeds of National Significance:

Noxious Weed Class 1

State Prohibited Weeds

Characteristics: Class 1 noxious weeds are plants that pose a potentially serious threat to primary production or the environment and are not present in the State or are present only to a limited extent.

Control objective: Prevent the introduction and establishment of those plants in NSW.

Example control requirements: These weeds must be eradicated from land and not allowed to re-establish. They are also ‘notifiable’, with a range of restrictions on their sale and movement.

NSW Noxious Weeds Act 1993

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

Noxious Weed Class 2

Regionally Prohibited Weeds

Characteristics: Class 2 noxious weeds are plants that pose a potentially serious threat to primary production or the environment of a region to which the order applies and are not present in the region or are present only to a limited extent.

Control objective: Prevent the introduction and establishment of those plants in parts of NSW.

Example control requirements: These plant must be eradicated from land and not allowed to re-establish. They are also ‘notifiable’, with a range of restrictions on their sale and movement.

NSW Noxious Weeds Act 1993

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

Noxious Weed Class 3

Regionally Controlled Weeds

Characteristics: Class 3 noxious weeds are plants that pose a serious threat to primary production or the environment of an area to which the order applies, are not widely distributed in the area and are likely to spread in the area or to another area.

Control objective: Reduce the area and the impact of those plants in parts of NSW.

Control action: The plant must be fully and continuously suppressed and destroyed.

NSW Noxious Weeds Act 1993

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

Noxious Weed Class 4

Locally Controlled Weeds

Characteristics: Class 4 noxious weeds are plants that pose a threat to primary production, the environment or human health, are widely distributed in an area to which the order applies and are likely to spread in the area or to another area.

Control objective: Minimise the negative impact of those plants on the economy, community or environment of NSW.

Example control requirements: The growth of the plant must be managed in a manner that reduces its numbers, spread and incidence, and continuously inhibits its reproduction. The plant may not be sold, propagated or knowingly distributed.

NSW Noxious Weeds Act 1993

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

Noxious Weed Class 5

Restricted Plants

Characteristics: Class 5 noxious weeds are plants that are likely, by their sale or the sale of their seeds or movement within the State or an area of the State, to spread in the State or outside the State.

Control objectives: Prevent the introduction of those plants into NSW, the spread of those plants within NSW or from NSW to another jurisdiction.

Example control requirements: There are no requirements to control existing Class 5 weeds. However, they are ‘notifiable’ and a range of restrictions on their sale and movement exists.

NSW Noxious Weeds Act 1993

Refer to the NSW Department of Primary Industry’s Noxious and Environmental Weed Control Handbook.

WoNS (Weeds of National Significance)

All of the Australian governments have agreed on a list of thirty-two Weeds of National significance.

These weeds were chosen because of their:

  • invasiveness,
  • potential for spread,
  • environmental, social and economic impacts, and
  • the potential to manage them successfully.

Managing Weeds of National Significance

If you have any of these weeds on land you own or manage, you have a responsibity to manage them.

The reason these weeds have special status is that managing them requires coordination by every level of government, organisations and responsible individuals.

There is a strategic plan for each of the Weeds of National Significance, making clear how everyone is to work together, from research through to on the ground action.

For more information, visit the Federal Environment website.