What is a noxious weed?

The most widely accepted definition of a weed is 'a plant growing where it is not wanted'. In NSW, noxious weeds are plants that have been declared under the Noxious Weeds Act 1993 by the Minister for Primary Industries. Weeds with the potential to impact on agriculture, animal or human health or damage the environment are potential candidates for declaration as noxious weeds. The Act gives the council power to require occupiers of land to control noxious weeds. If an occupier fails to do so, the council has the power to enter the land and to carry out the control work. The council can also issue a penalty notice or take prosecution action for offences under the Act. The main intent of the Act is to restrict the spread of serious weeds and protect other landholders from weed invasion. There is no point in declaring a weed noxious unless there is a firm intention to implement a practical, planned management program. Declaring a weed noxious does not, in itself, provide any benefits to ...  more

By definition of RCW 17.10.010, a noxious weed is a plant that, once established, is: Highly destructive Competitive or • Difficult to control using cultural or chemical (herbicide) practices In more specific terms, a noxious weed is a plant that was introduced to Washington State that is difficult to control and damaging to our economy and natural resources.  more

The term "Noxious Weed" is a political (rather than scientific) designation given to a plant that is non-native to North America and has aggressive, invasive tendencies in our area, giving it the potential for serious economic, agricultural, and/or ecological damage. Often these weeds are kept in check by natural controls (e.g. predators, environmental conditions, diseas, etc.) in their native territory. However, lacking such controls in our area, these plants are able to propagate very aggressively, allowing them to crowd out native plants and dominate local plant communities.  more

A weed is designated noxious when it is considered by a governmental agency to be injurious to public health, agriculture, recreation, wildlife, or property. In Idaho, noxious weed regulations are covered by Title 22, Chapter 24, Idaho Code, Noxious Weeds Law. Some general characteristics of noxious weeds are their ability to spread rapidly, reproduce in high numbers, and crowd out native plants. Noxious weeds also tend to be very difficult to control. Noxious weeds can be annuals (completing their life cycle in one growing season) or perennials (having a life cycle spanning more than one growing season). Most noxious weeds were originally from other countries. Many arrived in shipments of desirable seeds, in the ballast of sailing ships, or were introduced intentionally as garden plants. Noxious weeds thrive in disturbed areas like roadsides, building sites, maintenance areas, irrigation ditches, dirt parking areas, trails, and campgrounds. Once noxious weeds gain a foothold, they ...  more

The important distinction between noxious weeds and the rest of the terms used above is that ‘noxious’ is a legal term applied to a plant species designated as such by State and Federal law. Each State develops individual criteria for determining which plants will be considered as noxious and then generates a list unique to that State. States have developed laws that require the control or elimination of noxious weeds by landowners. An invasive plant may or may not be designated as noxious by a given State. For information on the Federal Noxious Weed Law go to http://www.aphis.usda.gov/ppq/weeds/. For information on which species are considered noxious by State you can click the following link http://invader.dbs.umt.edu to the Invaders Database. This database, developed by Peter Rice at the University of Montana, is a distribution database for invasive plant species in all Northwestern states. It provides a list of all known noxious weeds in the northwest states and links to web ...  more

The important distinction between noxious weeds and the rest of the terms used above is that 'noxious' is a legal term applied to a plant species designated as such by State and Federal law. Each State develops individual criteria for determining which plants will be considered as noxious and then generates a list unique to that State. States have developed laws that require the control or elimination of noxious weeds by landowners. An invasive plant may or may not be designated as noxious by a given State. For information on the Federal Noxious Weed Law go to http://www.aphis.usda.gov/ppq/weeds/. For information on which species are considered noxious by State you can click the following link http://invader.dbs.umt.edu to the Invaders Database. This database, developed by Peter Rice at the University of Montana, is a distribution database for invasive plant species in all Northwestern states. It provides a list of all known noxious weeds in the northwest states and links to web ...  more

Generally, the term weed is used to describe any plant that is unwanted and grows or spreads aggressively. The term exotic weed describes an invasive unwanted non-native plant. Terms such as invasive weed or noxious weed are used somewhat interchangeably to refer to weeds that infest large areas or cause economic and ecological damage to an area. The term noxious weed has legal ramifications in some states that maintain official lists of noxious weeds. What is considered a weed in one area may not be a weed in another. Native plants evolved over millions of years to fill unique ecological niches. What we know as weeds today (non-native, ecologically damaging plants) did not exist in the wilderness then. These plants developed in and are native to other countries. Like our native plants, they are kept in check in their native environment by insects or diseases and by competition with other species.  more

Noxious weeds are plant species that have been designated "noxious" by law. The word "noxious" simply means deleterious, and all listed weeds are deleterious by definition. There are hundreds of weed species in Idaho; however, only 35 are designated noxious by Idaho law as of 1977. Currently, the Idaho Department of Agriculture uses the following criteria for designation of a noxious weed: • It must be present in but not native to Idaho; • It must be potentially more harmful than beneficial to Idaho; • Eradication must be economically physically feasible; • The potential adverse impact of the weed must exceed the cost of control.  more

Noxious weeds have been divided into four (4) categories according to action needed for control, their extent and cost of control and the weeds importance. Definitions: W1 Weeds - Notifiable within 72 hours of detection. They are limited in distribution, pose a severe threat to agriculture, environment and community. W2 Weeds - Are a threat to agriculture, environment and community and have potential to spread. They must be fully and continously suppressed and destroyed. W3 Weeds - Have a similiar threat but are widespread. They must be prevented from spreading and its numbers and distribution reduced. W4 Weeds - Require special action or their control. Obligations and Penalties Every home owner, landowner, occupier or person(s) leasing or renting properties must be aware of their obligations and responsibilites to control noxious plants. The person(s) who has the care, control and use of the land is the occupier. They are resposible for the control of noxious plants. There are many ...  more

A noxious weed is one that can be injurious to peoples health. The pollen or spores of some noxious plants cause allergic reactions in susceptible people.  more