Idaho's Noxious Weeds

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 67 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.

Early Detection & Rapid Response

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

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

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.

Statewide EDRR List

Common NameMapScientific Name
Brazilian Elodea (PDF)Map (PDF)Egeria densa
Common/European Frogbit (PDF)Map (PDF)Hydrcharis morsus-ranae
Fanwort (PDF)Map (PDF)Cobomba caroliniana
Feathered Mosquito Fern (PDF)Map (PDF)Azolla pinnata
Giant Hogweed (PDF)Map (PDF)Heracleum mantegazzianum
Giant Salvinia (PDF)Map (PDF)Salvinia molesta
Iberian StarthistleMap (PDF)Centaurea iberica
Hydrilla (PDF)Map (PDF)Hydrilla verticillata
Policeman's Helmet (PDF)Map (PDF)Impatiens glandulifera
Purple StarthistleMap (PDF)Centaurea calcitrapa
Squarrose Knapweed (PDF)Map (PDF)Centaurea triumfetti
Syrian BeancaperMap (PDF)Zygophyllum fabago
Tall Hawkweed (PDF)Map (PDF)Hieracium piloselloides
Variable-Leaf-Milfoil (PDF)Map (PDF)Myriophyllum heterophyllum
Water Chestnut (PDF)Map (PDF)Trapa natans
Water HyacinthMap (PDF)Eichhornia crassipes
Yellow Devil Hawkweed (PDF)Map (PDF)Hieracium glomeratum
Yellow Floating Heart (PDF)Map (PDF)Nymphoides pelata

Statewide Control List

Common NameMapScientific Name
Black HenbaneMap (PDF)Hyoscyamus niger
Bohemian Knotweed (PDF)Map (PDF)Polygonum bohemicum
BuffaloburMap (PDF)Solanum rostratum
Common CrupinaMap (PDF)Crupina vulgaris
Common Reed (Phragmites) (PDF)Map (PDF)Phragmites australis
Dyer's WoadMap (PDF)Isatis Tinctoria
Eurasian WatermilfoilMap (PDF)Myriophyllum spicatum
Giant KnotweedMap (PDF)Polygonum sachalinense
Japanese KnotweedMap (PDF)Polygonum cuspidatum
JohnsongrassMap (PDF)Sorghum halepense
MatgrassMap (PDF)Nardus stricta
Meadow KnapweedMap (PDF)Centaurea debeauxii
Mediterranean Sage (PDF)Map (PDF)Salvia aethiopis
Musk ThistleMap (PDF)Carduus nutans
Orange HawkweedMap (PDF)Hieracium aurantiacum
Parrotfeather Milfoil (PDF)Map (PDF)Myriophyllum aquaticum
Perennial SowthistleMap (PDF)Sonchus arvensis
Russian KnapweedMap (PDF)Acroptilon repens
Scotch BroomMap (PDF)Cytisus scoparius
Small Bugloss (PDF)Map (PDF)Anchusa arvensis
Vipers Bugloss (PDF)Map (PDF)Echium vulgare
Yellow HawkweedMap (PDF)Hieracium caespitosum

Statewide Containment List

Common Name
Scientific Name
Canada ThistleMap (PDF)Cirsium arvense
Curlyleaf Pondweed (PDF)Map (PDF)Potamogeton crispus
Dalmatian ToadflaxMap (PDF)Linaria dalmatica ssp. dalmatica
Diffuse KnapweedMap (PDF)Centaurea diffusa
Field BindweedMap (PDF)Convolvulus arvensis
Flowering Rush (PDF)Map (PDF)Butomus umbelltus
Hoary Alyssum (PDF)Map (PDF)Berteroa incana
Houndstongue (PDF)Map (PDF)Cynoglossum officinale
Jointed GoatgrassMap (PDF)Aegilpos cylindrica
Leafy SpurgeMap (PDF)Euphorbia esula
MiliumMap (PDF)Milium vernale
Oxeye Daisy (PDF)Map (PDF)Leucanthemum vulgare
Perennial PepperweedMap (PDF)Lepidium latifolium
Plumeless Thistle (PDF)Map (PDF)Carduus acanthoides
Poison HemlockMap (PDF)Conium maculatum
PuncturevineMap (PDF)Tribulus terrestris
Purple LoosestrifeMap (PDF)Lythrum salicaria
Rush SkeletonweedMap (PDF)Chondrilla juncea
Saltcedar (PDF)Map (PDF)Tamarix sp.
Scotch ThistleMap (PDF)Onopordum acanthium
Spotted KnapweedMap (PDF)Centaurea stoebe
Tansy RagwortMap (PDF)Senecio jacobaea
White Bryony (PDF)Map (PDF)Bryonia alba
WhitetopMap (PDF)Cardaria draba
Yellow Flag Iris (PDF)Map (PDF)Iris psudocorus
Yellow StarthistleMap (PDF)Centaurea solstitialis
Yellow ToadflaxMap (PDF)Linaria vulgaris