Weeds are plants that cause problems. A modern definition of a weed is "a plant that requires some form of action to reduce its effect on the economy, the environment, human health and amenity". Many of the plants that are now considered to be weeds were introduced to Australia by early settlers, or by gardeners and farmers who had little or no knowledge of their future impact on the native environment.

To farmers, botanists or gardeners, the term ‘weed' may mean different things. This is why weeds are often classed in broad groups depending on their characteristics and impacts. The main groups of weeds are:

► Noxious Weeds
► Environmental Weeds
► Agricultural & Horticultural Weeds
► Weeds of National Significance (WONS)

Many weeds can be classified in more than one of these groups. For example, Blackberry can be classed as a noxious weed, environmental weed and agricultural weed, depending on its situation and is also listed as one of Australia's Weeds of National Significance (WONS).

Noxious Weeds - are those legally declared as noxious plants

Some serious weeds are required by law to be controlled by all landholders in an area. These are known as noxious weeds and the law that controls these in NSW is the Noxious Weeds Act 1993(the Act). Cobar Shire Council is the local control authority for the Cobar local government area (LGA) and as such Council is responsible for the implementation and enforcement of the Act. The Act requires all landholders in a defined area, including local government and state agencies, to control noxious weeds on land they occupy. 

Weeds that are declared noxious are those weeds that have potential to cause harm to the community and individuals, can be controlled by reasonable means and most importantly, have the potential to spread within an area and to other areas. A weed is declared noxious because its control will provide a benefit to the community over and above the cost of implementing control programs. Many ‘bad' weeds do not meet the criteria for declaration. Noxious weeds will have limited distribution with the potential to become more widespread and will cause impact on agriculture, human health or the environment.

There are five classes of noxious weeds identified in the Act:

Class 1 - State Prohibited Weeds. The plant must be eradicated from the land and the land must be kept free of the plant.

Class 2 - Regionally Prohibited Weeds. The plant must be eradicated from the land and the land must be kept free of the plant.

Class 3 - Regionally Controlled Weeds. The plant must be fully and continuously suppressed and destroyed.

Class 4 - Locally Controlled Weeds. The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority.

Note: If the plant declared as a Class 4 weed is also considered to have the potential to be sold, propagated or distributed, then Class 4 has the expanded control definition as follows:

"The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority and the plant may not be sold, propagated or knowingly distributed".

Class 5 - Restricted Plants. The requirements in the Act for a notifiable weed must be complied with.

A noxious weed that is classified as a Class 1, 2 or 5 is referred to in the Act as a notifiable weed. This means, inter alia, that the Council must be notified of the presence of such weeds within three (3) days of their detection. Also, all Class 1, 2 and 5 weeds are prohibited from sale in NSW.

There is currently a total of 88 plant species declared noxious for the Cobar LGA within the following Weed Control Classes:

Class 1 - 30

Class 2 - 7

Class 3 - 3

Class 4 - 20

Class 5 - 28

The majority of weeds declared noxious for the Cobar LGA are not known to be present within the LGA. However, having these weeds listed gives Council as the Local Control Authority immediate regulatory control over any reported occurrence on private land and the ability to respond rapidly with appropriate control measures on Council-managed public land in order to prevent their establishment within the area.

The current list of noxious weeds for the Cobar LGA can be found on the website of Industry and Investment NSW.

Class 4 Noxious Weed Management Plans

The Class 4 classification under the Noxious Weeds Act 1993allows for more flexibility in the method, extent and timing of weed control for Class 4 weeds. The following Class 4 Noxious Weed Management Plans specify how the Class 4 weeds declared for the Cobar LGA are to be managed. 

The growth of the plants identified below must be managed in a manner that reduces its numbers spread and incidence and continuously inhibits its reproduction.

Updated 23/3/2012

Environmental Weeds

Environmental weeds are plants that are 'out of place' in the natural environment and are not a 'normal' part of Australian ecosystems. They are plants that have the potential to impact the natural environment by destroying habitat or over-running indigenous species and altering local biodiversity. Some examples of environmental weeds include Bridal Creeper, Bitou Bush, Boneseed, Blackberry and Lantana.

Environmental weeds can also be native Australian plants that are not local to the area they are growing in.  Non-indigenous (that is, not local) species may invade and displace species natural to that area or they may cross pollinate to produce new species which may in time, alter regional biodiversity. Cootamundra Wattle Acacia baileyana is a good example of the former, while many eucalypts are known to interbreed.

Of the almost 3000 introduced plant species known to be established in the Australian environment, 65% are ‘escaped' garden plants.

Agricultural Weeds

Agricultural and horticultural weeds are those plants that have a negative effect on crop or animal production.  They reduce the area available for agricultural activities, interfere with agricultural practices and affect the quality of produce. Some examples of agricultural weeds are Serrated Tussock, Thistles, Blue Heliotrope, St John's Wort, Paterson's Curse and Blackberry

Weeds of National Significance (WONS)

Weeds of National Significance (WONS) are those plants which have been declared by the Federal government under the National Weeds Strategyand regarded as the worst weeds in Australia because of their invasiveness, potential for spread, and economic and environmental impacts. The WONS weeds are:

• Alligator Weed
• Athel Pine
• Bitou Bush/Boneseed
• Blackberry
• Bridal Creeper
• Cabomba
• Chilean Needle Grass
• Gorse
• Hymenachne
• Lantana
• Mesquite
• Mimosa
• Parkinsonia
• Parthenium Weed
• Pond Apple
• Prickly Acacia
• Rubber Vine
• Salvinia
• Serrated Tussock
• Willow

More information: http://www.weeds.gov.au/weeds/lists/wons.html

What can you do?

We can all take action to help reduce the impact of weeds in the Cobar Shire. Here are some helpful tips:

Get to know the local weeds so that if you spot them, you can report them to Council's Weeds Officer;

Learn about local native plants in the Cobar area and plant them in your garden;

Be aware that weed seeds are transported on vehicles, trailers, clothing, shoes, in soil and in pet or livestock fur and hair;

Always stick to designated tracks when walking, horse riding, driving, or riding pushbikes or motorbikes through natural areas;

Dispose of weeds that are already seeding or readily able to reproduce vegetatively by placing them in a black plastic bag, sealing it and "baking it" in the sun until destroyed. This method alone may not kill all parts of the weed, for example bulbs, and may need to be used in combination with other methods such as mulching. If unsure, contact Council's Weeds Officer for advice;

Compost or dispose of other garden and green waste in your own yard or by carefully transporting it to Council's green waste section at the tip.  NEVER dump garden waste over the back fence or in public reserve areas; and

Always cover trailers when transporting plant material to prevent seeds and other live plant material falling off.Cobar Shire Council is committed to the control of weeds and engages qualified field staff and contractor specialists in weed management throughout the LGA and seeks funding opportunities in support of its weed management efforts. Importantly, the control of weeds locally within the LGA contributes to the control of weeds regionally, a central goal of the Macquarie Valley, and Lachlan Valley, Weeds Advisory Committees, both of which Cobar Shire Council is a contributing member.

Further Information and Resources

There are plenty of sources of information regarding weeds; it can become overwhelming! Here are some useful sources of information to help you learn more about weeds:

Cobar Shire Council - Weed Management Staff:

Council Office: 36 Linsley Street (PO Box 223), Cobar NSW 2835. Phone: (02) 6836 5888, Fax: (02) 6836 5889
Melissa Gunn - Noxious Weeds Officer, Mobile: 0428 273 578, Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Western Weeds - Website for the Macquarie Valley Weeds Advisory Committee (MVWAC) and Lachlan Valley Weeds Advisory Committee (LVWAC). These committees cover a combined area of more than 350 000 sq kms, equal to over 40% of NSW.

Industry & Investment NSW -New South Wales Government department website with plenty of information about  weed management, noxious weed declarations, publications, etc.

Weeds In Australia - A national website resource hosted by the Australian Weeds Committee to promote access to key weed policies, regulations, current issues, national initiatives, research, extension, training and personnel.

The Nursery & Garden Industry NSW & ACT -NGINA website provides an extensive range of information about gardens, gardening, invasive plants, and local nurseries.

Weeds CRC - The Cooperative Research Centre for Australian Weed Management website is an excellent reference containing a substantial amount of general and technical information regarding weed management including guidelines, research, fact sheets, education and training resources.