Noxious Weeds

Plants considered harmful to animals or the environment, typically (but not always) non-native species which spread at the expense of native vegetation.

Related resource topics for county planning include the following:


Map of Data

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Resource Information
There are many species of exotic and invasive weeds in the Utah. Some species, however, have more potential to be “injurious to public health, crops, livestock, land, or other property[1]. The Utah Noxious Weed Act of 2008 had defined 28 noxious weed species into three prioritization categories. In December 2015 the official State Noxious Weed list was updated to include 54 species and prioritization categories were modified as follows:

Class 1A: Early Detection Rapid Response (EDRR) watch list
Declared noxious weeds and invasive weeds that are not native to the State of Utah, are not known to exist in the state but pose a serious threat, and should be considered a very high priority.

Common crupina
Crupina vulgaris
Syrian bean caper
Zygophyllum fabago
African rue
Peganum harmala
Ventenata (North Africa grass)
Ventenata dubia
Small bugloss
Anchusa arvensis
Plumeless thistle
Carduus acanthoides
Mediterranean sage
Salvia aethiopis
Malta starthistle
Centaurea melitensis
Spring millet
Milium vernale

Class 1B : Early Detection Rapid Response (EDRR)
Declared noxious and invasive weeds not native to the State of Utah that are known to exist in the state in very limited populations, pose a serious threat to the state, and should be considered as a very high priority.

Alhagi maurorum
Japanese knotweed
Polygonum cuspidatum
Garlic mustard
Alliaria petiolata
Blueweed (Viper's bugloss)
Echium vulgare
Purple starthistle
Centaurea calcitrapa
Elongated mustard
Brassica elongata
Galega officinalis
Common St. Johnswort
Hypericum perforatum
African mustard
Brassica tournefortii
Oxeye daisy
Leucanthemum vulgare
Giant reed
Arundo donax
Cutleaf viper grass
Scorzonera laciniata

Class 2: Control
Declared noxious and invasive weeds not native to the State of Utah that pose a threat to the state and should be considered a high priority for control. Weeds listed in the control list are known to exist in varying populations throughout the state. The concentration of these weeds are at levels for which control or eradication may be possible.

Leafy spurge
Euphorbia esula
Dyers woad
Isatis tinctoria
Taeniatherum caput-medusae
Yellow starthistle
Centaurea solstitialis
Rush skeletonweed
Chondrilla juncea
Yellow toadflax
Linaria vulgaris
Spotted knapweed
Centaurea stoebe
Diffuse knapweed
Centaurea diffusa
Purple loosestrife
Lythrum salicaria
Black henbane
Hyoscyamus niger
Squarrose knapweed
Centaurea virgata
Dalmatian toadflax
Linaria dalmatica

Class 3: Containment
Declared noxious and invasive weeds not native to the State of Utah that are widely spread. Weeds listed in the containment noxious weeds list are known to exist in various populations throughout the state. Weed control efforts may be directed at reducing or eliminating new or expanding weed populations. Known and established weed populations, as determined by the weed control authority, may be managed by any approved weed control methodology, as determined by the weed control authority. These weeds pose a threat to the agricultural industry and agricultural products.

Russian knapweed
Acroptilon repens
Musk thistle
Carduus nutans
Cynoglossum officinale
Elymus repens
Perennial pepperweed (Tall whitetop)
Lepidium latifolium
Jointed goatgrass
Aegilops cylindrica
Phragmites (Common reed)
Phragmites australis ssp.
Cynodon dactylon
Tamarix ramosissima
Perennial Sorghum spp.
Sorghum halepense
Sorghum almum
Hoary cress
Cardaria spp.
Scotch thistle (Cotton thistle)
Onopordum acanthium
Canada thistle
Cirsium arvense
Field bindweed (Wild Morning-glory)
Convolvulus spp.
Poison hemlock
Conium maculatum
Puncturevine (Goathead)
Tribulus terrestris
*Bermudagrass (Cynodon dactylon) shall not be a noxious weed in Washington County and shall not be subject to provisions of the Utah Noxious Weed Law within the boundaries of that county.

Class 4: Prohibited
Declared noxious and invasive weeds, not native to the State of Utah, that pose a threat to the state through the retail sale or propagation in the nursery and greenhouse industry. Prohibited noxious weeds are annual, biennial, or perennial plants that have the potential or are known to be detrimental to human or animal health, the environment, public roads, crops, or other property.

Cogongrass (Japanese blood grass)
Imperata cylindrica
Scotch broom
Cytisus scoparius
Myrtle spurge
Euphorbia myrsinites
Russian olive
Elaeagnus angustifolia
Dames Rocket
Hesperis matronalis

State land managers, local governments, and property owners are responsible for controlling weed species found on the state’s noxious weeds list, and local weed species of concern, if necessary. Weed control responsibilities extend to lands under local management (roads, right-of-ways, parks, etc.) as well as enforcing provisions of the Utah Noxious Weed Act on private lands. If landowners are unwilling or unable to address weed problems on their own land, state law provides county weed managers the right to treat weeds on private lands (assuming proper notice is provided) and subsequently seek reimbursement or apply liens for the work.

For the MAG region, there are county, state, and federal goals identified in respective planning documents. In general, county objectives for noxious weeds are similar to those of the state; counties support the goals and objectives of the Utah Noxious Weeds Act for all landowners, including the federal government. Counties expect federal land managers to control weeds on public lands.

Local weed control entities:

County-specific weed control assessments from Utah Association of Conservation Districts (UACD) and Natural Resource Conservation (NRCS):

Regional and state weed management plans:

Federal land management agencies:

Best Management Practices

Prevention and early treatment are the most cost-effective best management practices (BMPs) [2]. Small areas are much less expensive to treat than those left to spread across the landscape. However, many weeds have expanded to large-scale infestations and can only be treated with substantial effort and cost. Each species of noxious weed has unique ways of dispersing, propagating, and spreading, making treatment methods highly variable. The following BMP’s cover general topics of weed control.  

Foster a general appreciation among the public and local government officials regarding the seriousness of noxious weeds within the counties, including long-term cost and other natural resource impacts. Also provide information about enforcement of existing county and state noxious weed laws as well potential funding sources and coordination among landowners and managers [3].      

Prevention and Early Detection
Noxious weeds are easily spread by contaminated agricultural machinery, pack stock, riding stock, livestock feed, hay, straw, soils, sod, nursery stock, and manure. Preventive measures include [3]:

  • Certified weed-free feed for all stock animals.
  • Certified weed-free mixes, mulch, fill, etc., for restoration/rehabilitation activities.
  • Thoroughly cleaning agriculture machinery and equipment (which has come in contact with weeds) before it is transported to other locations.
  • Prevent spilling and accidental spreading of materials from vehicles transporting seed, feed, topsoil and fill materials.
  • Educate landowners, land users, and visitors about the impacts of noxious weeds.

Once established, weeds must be treated to control further spread. Treatments include [4]:

  • Chemical control and containment (hand, vehicle, aerial)
  • Mechanical treatments (mowing, discing)
  • Biological (insects, grazing livestock such as goats and cattle)
  • Physical (water removal, flooding, burning)

The Noxious Weeds data combined with the Ownership data can be used to identify large infestation areas within the county and the ownership of nearby land. Other weed control and treatment resources include:

Cooperative Weed Management Areas (CWMAs): Weed control is most effective when all land managers and landowners act quickly to address infestations when they first begin. As the name implies, CWMAs are cooperatives of agencies, departments, and organizations that work together to provide weed control across large lands areas, like watersheds, without specific consideration of land ownership, to more effectively treat weeds. CWMAs are also used to coordinate treatment efforts and pool resources.

CWMAs and their partners within the WFRC area include;

Mindy Wheeler
WP NRC, Inc.
PO Box 520604
Salt Lake City, UT 84152

Craig Searle
2855 S. State St.
Provo, UT 84606

Stephen Smith
2210 S. Hwy 40, Suite B
Heber City, UT 84032


Economic Considerations

Weeds create significant economic impacts that must be considered in each county’s resource management plan. Annual economic losses in the United States from weeds is over $20 billion [5]. It is estimated that, without the use of herbicides, revenue losses to the agricultural sector would increase by about 500% [6].

Economic considerations for counties include:

  • Direct expenditures. The UDWR allocates $200,000 annually to treat weeds [6].
  • $215,000 was spent in 2104 to eradicate approximately 3,800 acres of phragmites at Utah Lake [7].
  • Reduce range carrying capacity for livestock and grazing. Dyers woad infestations can spread 14% per year and reduce range carrying capacity by 38% [8]. The BLM has estimated costs in the western United States for weed control and lost production at $100,000,000 per year [9].
  • Wildland fire. Contiguous patches of weeds pose significant fire risks, and seeding after wildfire is a necessity to recruit native species rather than weeds.
  • Agriculture. Direct control costs, crop and seed contamination, and equipment cleaning costs.
  • Wasatch County’s Coordinate Noxious Weed Management Plan states that, “The loss of (land) value may be reduced as much as $100 to $300 per/acre depending on the noxious weed involved.

Impact Considerations
  • Wildlife habitat. Phragmites outcompetes native wetland vegetation and chokes out wildlife [10].
  • Weed control impacts. Fire is a control method often used to treat phragmites, but smoke is a significant air-quality issue, which must be considered in this region.
  • Increased wildfire risk and costs. Many noxious weeds, such as cheatgrass, are very flammable and increase the risk of wildfires. After a fire burns an area infested with noxious weeds, the weeds sprout before native plants and are able to dominate native plant species by quickly taking over water and soil resources [11].
  • Recreation impacts. Tamarisk and Russian olive grow very thick in riparian areas along rivers making it difficult for river users to access recreation resources. Goathead (puncture vine) causes problems for cyclists and trail users.

Data Download
  GIS Data Map Service Web Map Document  Tabular Data  Website
Data NameData ExplanationPublication DateSpatial AccuracyContact
Early Detection Distribution Maps (EDDMaps)
Early detection and distribution mapping system (requires free log in)Live dataVariableCenter for Invasive Species and Ecosystem Health
Forest Service Weeds

Invasive Plant Infestation polygons collected by the National Invasive Plant Inventory ProtocolLive dataVariable
Land Ownership
Surface Land Ownership; use Admin field to identify administrative agencyUpdated Weekly1:24,000State of Utah School and Institutional Trust Lands Administration (SITLA).
GIS Group
Noxious Weeds in Utah
Identified weed locations in Utah1/18/2013VariableAGRC


  1. Utah State Legislature. 2015. Utah Noxious Weed Act – Administrative Rules. Enacted July 2, 2008, Modified December 15, 2015. Accessed: January 25, 2016.
  2. Beck, G. K. N.D. Economics of Invasive Weed Control: Chemical, Manual/ Physical/Fire, Biological, and Doing Nothing. Invasive Plant Management Technical Webinar Series.
  3. Webster, Bert. 2009. Wasatch County Public Works Department: Coordinated Noxious Weed Plan for Wasatch County.
  4. Utah Department of Natural Resources, Utah Division of Wildlife Resources. 2009. Information Document for Invasive and Noxious Weed Control Project on Utah’s Waterfowl Management Areas. Publication No. 09-14., Salt Lake City, Utah
  5. Utah State University. 2010. Noxious Weed Field Guide 4th Edition.
  6. Utah Weed Control Association. 2004. The Utah Strategic Plan for Managing Noxious and Invasive Weeds.
  7. Utah Lake Commission. 2016. Phragmites Removal 2014. Accessed: August 08, 2016.
  8. US Department of the Interior, Bureau of Land Management, Oregon State Office. 1985. Northwest Area noxious weed control program: Environmental Impact Statement–Final. Portland, OR: US Department of the Interior, Bureau of Land Management, Oregon State Office.
  9. US Department of the Interior, Bureau of Land Management. 2011. “Noxious Weeds – A Growing Problem Uintah Basin Weed Management Partnership.”  Accessed: February 15, 2016.
  10. Schuske, K. 2013. An Invasive Grass Is Choking Utah’s Wetlands. Explore Utah Science. Accessed: February 15, 2016.
  11. Idaho Firewise. 2015. Wildfire and Idaho Landscape. Accessed: February 02, 2016