This Noxious Weed List contains information about Idaho’s noxious weeds. Just click on the name of a weed you want to learn more about. You will be given the best control methods available to manage that weed. Idahoans can contact their County Weed Control Superintendent or a Private Applicator for technical assistance in dealing with the control and management of noxious weeds.

PLEASE NOTE – The proper use and application of herbicides can be an effective way to control and eradicate noxious and invasive plants. Before using herbicides, always carefully follow the label and safety instructions on the label. While we recommend the use of herbicides as one of the effective tools for integrated pest management, the Idaho Weed Awareness Campaign assumes no liability for herbicide application.

Black Henbane

Black Henbane
Hyoscyamus niger

Japanese Knotweed

Bohemian Knotweed
Polygonum bohemicum

Brazilian Elodea
Egeria densa


Solanum rostratum

Canada Thistle
Cirsium arvense

Common Crupina
Crupina vulgaris

Common/European Frogbit
Hydrcharis morsus-ranae

Common Reed (Phragmites)
Phragmites australis

Curelyleaf pondweed

Curlyleaf Pondweed
Potamogeton crispus

Dalmatian Toadflax
Linaria genistifolia ssp. dalmatica

 Diffuse knapweed

Diffuse Knapweed
Centaurea diffusa

Dyer’s Woad
Isatis tinctoria

Eurasian Watermilfoil
Myriophyllum spicatum


Cobomba caroliniana

Feathered Mosquito Fern
Azolla pinnata

Field Bindweed
Convolvulus arvensis

Flowering Rush
Butomus umbelltus

Giant Hogweed
Heracleum mantegazzianum

Giant Knotweed
Polygonum sachalinense

Giant Salvinia
Salvinia molesta

Hoary Alyssum
Berteroa incana

Hoary Cress (Whitetop)
Lepidium draba ssp. draba


Cynoglossum officinale


Hydrilla verticillata

Iberian Starthistle
C. iberica

Japanese Knotweed

Japanese Knotweed
Polygonum cuspidatum

Sorghum halepense

Jointed Goatgrass
Aegilops cylindrica

Leafy Spurge
Euphorbia esula

Nardus stricta

Meadow Hawkweed
Hieracium caespitosum

Meadow Knapweed
Centaurea debeauxii

Mediterranean Sage
Salvia aethiopis

Milium vernale

Musk Thistle
Carduus nutans

Orange Hawkweed
Hieracium aurantiacum

Oxeye Daisy

Oxeye Daisy
Chrysanthemum leucanthemum

Parrotfeather milfoil

Parrotfeather Milfoil
Myriophyllum aquaticum

Perennial Pepperweed
Lepidium latifolium

Perennial Sowthistle
Sonchus arvensis

Plumeless Thistle

Plumeless Thistle
Carduus acanthoides

Poison Hemlock
Conium maculatum

Policeman’s Helmet

Policeman’s Helmet
Impatiens glandulifera

Tribulus terrestris

Purple Loosestrife
Lythrum salicaria

Purple Starthistle
Centaurea calcitrapa

Rush Skeletonweed
Chondrilla juncea

Russian Knapweed

Russian Knapweed
Acroptilon repens

Tamarix ssp.

Scotch Broom
Cytisus scoparius

Scotch Thistle
Onopordum acanthium

Small Bugloss
Anchusa arvensis

Spotted Knapweed
Centaurea stoebe ssp. micranthos

Squarrose Knapweed
Centaurea triumfetti

Syrian Beancaper
Zygophyllum fabago

Tall Hawkweed
Hieracium piloselloides

Tansy Ragwort

Tansy Ragwort
Senecia jacobaea

Variable Leaf Milfoil
Myriophyllum heterophyllum

Vipers Bugloss
Echium vulgare

Water Chestnut
Trapa natans

Water Hyacinth
Eichhornia crassipes

White Bryony
Bryonya alba

Yellow Devil Hawkweed
Hieracium glomeratum

Yellow Flag Iris
Iris psudocorus


Yellow Floating-Heart
Nymphoides pelata

Yellow Star Thistle
Centaurea solstitialis

Yellow Toadflax
Linaria vulgaris