The purpose of this classification system is to:
Criteria for determining the economic and environmental significance of noxious weeds Detrimental effects
- Act as the Oregon Department of Agriculture's official guideline for prioritizing and implementing noxious weed control projects.
Assist the Oregon Department of Agriculture in the distribution of available funds for Oregon State Weed Board grants and county weed control requests.
Serve as a model for the private and public sectors in developing noxious weed classification systems.
- A plant species that causes or has the potential to cause severe production losses or increased control costs to the agricultural or horticultural industries of Oregon.
- A plant species that has the potential to or does endanger native flora and fauna by its encroachment into forest, range, and conservation areas.
- A plant species that has the potential or does hamper the full utilization and enjoyment of recreational areas.
- A plant species that is poisonous, injurious, or otherwise harmful to humans and animals.
- A plant that reproduces by seeds capable of being dispersed over wide areas or that is long-lived, or produced in large numbers.
- A plant species that reproduces and spreads by tubers, creeping roots, stolons, rhizomes or other natural vegetative means.
Difficulty of control
- A weed of known economic importance which is not known to occur in Oregon or occurs in small enough infestations to make eradication/containment possible; however its presence in neighboring states makes future occurrence seem imminent.
- A weed of economic or ecological importance and of limited distribution in Oregon.
- A weed that has not infested the full extent of its potential habitat in Oregon.
A plant species that is not easily controlled with current management practices such as chemical, cultural, biological, and physical methods.
Noxious weed control rating system
Noxious weeds, for the purpose of this system, shall be designated “A” or “B” and may be given the additional designation of “T” according to the Oregon Department of Agriculture Noxious Weed Classification System.
“A” classified Weed – a weed of known economic importance which is not known to occur in Oregon, or occurs in small enough infestations to make eradication/containment possible; however, its presence in neighboring states make future occurrence seem imminent.
Recommended action: Infestations are subject to eradication or intensive control when and where found
“B” classified Weed – a weed of economic importance which is regionally abundant, but which may have limited distribution in some counties.
Recommended action: Limited to intensive control at the state, county or regional level as determined on a case-by-case basis. Where implementation of a fully integrated statewide management plan is not feasible, biological control (when available) shall be the main control approach. (“B” weeds targeted for biological control are identified with an asterisk).
“T” classified Weed – a priority noxious weed designated by the Oregon State Weed Board as a target on which the Oregon Department of Agriculture will develop and implement a statewide management plan. “T” designated noxious weeds are species selected from either the “A” or “B” list. Oregon Noxious Weed Policy and Classification System (pdf)Noxious Weed Listing Process