What is a Noxious Weed?

Definition of a Common/Nuisance Weed:

Any plant which is seen as bothersome and is ordinarily found throughout the state. Common weeds have varying levels of negative impact and are normally not particularly invasive or difficult to control. These plants are not regulated by the state.

    Definition of an Invasive Weed:

    Invasive weeds are weeds that are non-native, spread prolifically, and are likely to cause harm or damage to the native ecosystem and species in which they are invading. This is because many of these species do not have any natural predators to which they are introduced such as animals or insects. Some of these species are extremely drought tolerant, shade tolerant, and fire-adapted, meaning they establish quickly after disturbances and outcompete native species for nutrients. Several of these species have seeds that can remain viable in the soil for many years, making it difficult to eradicate. Many of the species on the Nevada noxious weeds list are considered extremely invasive, but not all invasive plant species present in Nevada are listed as noxious.

    Purple Loosestrife 
    Category A Species Purple loosestrife in Washoe County, NV

      Definition of a Noxious Weed:

      The Nevada Revised Statutes (NRS) defines a noxious weed as "any species of plant which is, or likely to be, detrimental or destructive and difficult to control or eradicate." According to NRS 555.150, all landowners are responsible for controlling noxious weeds on their property. Per NRS 555.130, “The State Quarantine Officer may declare by regulation the weeds of the state that are noxious weeds. After holding a public meeting, the State Quarantine Officer may temporarily designate a weed as a noxious weed if he or she determines that immediate control of the weed is necessary.” All noxious weeds are regulated by the Nevada Department of Agriculture.


      Dyers Woad
      Catagory A Species Dyer's Woad in Elko County, NV


      Noxious weeds are typically non-native plants, but they do not have to be. For example, western water hemlock is a listed Nevada noxious weed species, but it is native to North America. This species is listed on the state noxious weed list due to its potential health hazards that pose a significant danger to either humans or animals. It is always important to identify species before

      removing or handling them to know if they pose any health risks or if they are a native look-alike species to the noxious species and therefore should not be removed. Please see the section “How to Report Noxious Weeds" on the NDA website for helpful tips on how to report noxious species in Nevada. 

      Noxious weeds are categorized into three groups: Category A, Category B, Category C. Category A species are prioritized to be controlled first as the goal is to eliminate the infestations before they become too far spread throughout the state and therefore are extremely difficult to control. To see the most current noxious weeds, you can visit either Noxious Weed Species list or the Nevada Noxious Weeds Field Guide. Please see the breakdown of noxious weed categories below: 

      Category A: weeds that are generally not found or that are limited in distribution throughout the State.

      Category B: weeds that are generally established in scattered populations in some counties of the State.

      Category C: weeds that are generally established and generally widespread in many counties of the State.

        Listing of a Noxious Weed

        Any change in the Nevada Noxious Weed List in NAC requires an administrative regulation change. The steps for an administrative regulation change can be found in the Administrative Rulemaking Procedural Guidelines document linked below. A simplified description of these steps includes the following:

        1. An official request for list change must be submitted to the NDA with written documentation describing the need and reasons for the change and additional supporting evidence for such change.
          * Once all documentation has been received, it is at the discretion of the Nevada Noxious Weeds Coordinator/State Quarantine Officer for the initial request to continue through the administrative regulation change procedures.
        2. The State Noxious Weed Coordinator must present all information for the proposed administrative regulation change to the Nevada Board of Agriculture for approval.
        3. Once approved by the Board of Agriculture the proposed administrative regulation change must go to workshop and hearing.
        4. After workshop and hearing a motion must be made and favored again by the Board of Agriculture to continue to Legislative Council Bureau and/or subcommittee for approval.
        5. Once approved at the legislative level the change will be enacted.

          How do noxious weeds spread?

          Noxious weeds may have been introduced either purposely for use as an ornamental or accidentally by being transported on boats (i.e. shipping palettes), vehicles (i.e. tires), or even people (clothing, shoes, etc.). It is always important to check all clothing and gear both before and after traveling or recreating to help prevent the spread of seeds or propagative plant parts. To see more information on how to prevent the spread of noxious weeds, please visit the North American Invasive Species Management Association’s (NAISMA)  Play Clean Go website.