Idaho's Noxious Weeds


Noxious weeds are plant species that are non-native and invasive by nature. Many of these species make significant modifications to the landscape. Idaho currently has 71 listed noxious weeds throughout the state. There are different categories of control for each noxious weed as stipulated in the Idaho Administrative Procedures Act 02, Title 06, chapter 22, Noxious Weed Rules. The categories affect how each weed is managed.

  • Statewide Prohibited Genera- All plants, plant parts, and subtaxa of listed genera are prohibited in Idaho
  • Statewide Early Detection and Rapid Response (EDRR) - plants in this category must be reported to the Idaho State Department of Agriculture (ISDA) within 10 days after being identified at the University of Idaho or by another qualified authority approved by the ISDA director. Eradication of these weeds must begin in the same season they are found.
  • Statewide Control - plants in this list may already exist in some parts of the state. In some areas of the state control or eradication is possible and a plan must be written that will reduce infestations within five years.
  • Statewide Containment - plants in this category exist in the state. New or small infestations can be reduced or eliminated, while established populations may be managed as determined by the weed control authority, which is usually the county weed program.

Idaho's 71 Noxious Weeds

Idaho has 71different species of weeds which are designated noxious by state law. The spread of these weeds and the damage they do to Idaho agriculture can be lessened through proper identification and handling. Visit the Idaho Department of Agriculture for more information

Temporary Listing:

Cogon Grass (Imperata Cylidrica), EDRR

Statewide Prohibited Genera










Statewide EDRR List

Common NameScientific Name
Brazilian ElodeaEgeria densa
Common/European FrogbitHydrcharis morsus-ranae
FanwortCobomba caroliniana
Feathered Mosquito FernAzolla pinnata
Giant HogweedHeracleum mantegazzianum
Giant SalviniaSalvinia molesta
GoatsrueGalega officinalis
HydrillaHydrilla verticillata
Iberian StarthistleCentaurea iberica
Policeman's HelmetImpatiens glandulifera
Purple StarthistleCentaurea calcitrapa L.
Squarrose KnapweedCentaurea triumfetti
Syrian BeancaperZygophyllum fabago
Tall HawkweedHieracium piloselloides
Variable-Leaf-MilfoilMyriophyllum heterophyllum
Water ChestnutTrapa natans
Yellow Devil HawkweedHieracium glomeratum
Yellow Floating HeartNymphoides pelata

Statewide Control List

Common NameScientific Name
Black HenbaneHyoscyamus niger
Bohemian KnotweedPolygonum bohemicum
BuffaloburSolanum rostratum
Common CrupinaCrupina vulgaris
Common Reed (Phragmites)Phragmites australis
Dyer's WoadIsatis Tinctoria
Eurasian WatermilfoilMyriophyllum spicatum
Flowering RushButomus umbelltus
Giant KnotweedPolygonum sachalinense
Japanese KnotweedPolygonum cuspidatum
JohnsongrassSorghum halepense
MatgrassNardus stricta
Meadow KnapweedCentaurea debeauxii
Mediterranean SageSalvia aethiopis
Musk ThistleCarduus nutans
Orange HawkweedHieracium aurantiacum
Parrotfeather MilfoilMyriophyllum aquaticum
Perennial SowthistleSonchus arvensis
Russian KnapweedAcroptilon repens
Scotch BroomCytisus scoparius
Small BuglossAnchusa arvensis
Vipers BuglossEchium vulgare
Yellow HawkweedHieracium caespitosum

Statewide Containment List

Common NameScientific Name
Canada ThistleCirsium arvense
Curlyleaf PondweedPotamogeton crispus
Dalmatian ToadflaxLinaria dalmatica ssp. dalmatica
Diffuse KnapweedCentaurea diffusa
Field BindweedConvolvulus arvensis
Hoary AlyssumBerteroa incana
HoundstongueCynoglossum officinale
Jointed GoatgrassAegilpos cylindrica
Leafy SpurgeEuphorbia esula
MiliumMilium vernale
Oxeye DaisyLeucanthemum vulgare
Perennial PepperweedLepidium latifolium
Plumeless ThistleCarduus acanthoides
Poison HemlockConium maculatum
PuncturevineTribulus terrestris
Purple LoosestrifeLythrum salicaria
Rush SkeletonweedChondrilla juncea
SaltcedarTamarix sp.
Scotch ThistleOnopordum acanthium
Spotted KnapweedCentaurea stoebe
Tansy RagwortSenecio jacobaea
White BryonyBryonia alba
WhitetopCardaria draba
Yellow Flag IrisIris psudocorus
Yellow StarthistleCentaurea solstitialis
Yellow ToadflaxLinaria vulgaris