WSU Extension

Hortsense

Weeds
 
Annual bluegrass 
Barnyardgrass 
Bentgrass, creeping 
Bermudagrass 
Bittercress (Shotweed, Hairy bittercress) 
Bittersweet nightshade (European bittersweet) 
Black medic 
Blackberry (Himalayan, Evergreen, Pacific) 
Blue mustard (Purple mustard, Tenella mustard) 
Brackenfern, western 
Buffalobur 
Bull thistle 
Buttercup, creeping 
Canada thistle 
Catchweed bedstraw (Cleavers) 
Catsear, common (False dandelion) 
Chickweed, common and mouseear 
Clover 
Comfrey 
Crabgrass 
Dandelion 
Dock (Curly, Broadleaf) 
Dodder 
Downy brome (Cheatgrass, Downy chess) 
Dwarf mistletoes 
English daisy (Lawn daisy) 
English ivy 
Field bindweed (Wild morningglory) 
Field pennycress (Fanweed) 
Flixweed 
Foxtail (Green, Yellow, Bristly) 
Garden loosestrife 
Giant hogweed 
Goldenrods 
Groundsel, common 
Hawkweeds 
Hedge bindweed 
Henbit 
Herb Robert (Robert geranium, stinky Bob) 
Horsetails (Scouringrush) 
Horseweed (Marestail) 
Knapweeds 
Knotweeds (Bohemian, Giant, Japanese, Himalayan) 
Kochia 
Lambsquarters, common 
Liverworts 
Mallow, common (Cheeseweed, Buttonweed) 
Nightshades 
Oxalis (Creeping woodsorrel) 
Parrotfeather and Eurasian watermilfoil 
Pineappleweed 
Plantain (Broadleaf, Buckhorn) 
Poison hemlock 
Poison ivy and Poison oak 
Prickly lettuce (China lettuce) 
Prostrate knotweed 
Puncturevine (Tackweed, Goathead) 
Purple deadnettle (Red deadnettle) 
Purple loosestrife (Purple lythrum) 
Purslane, common 
Quackgrass 
Red sorrel (Sheep sorrel) 
Redroot pigweed (Rough pigweed) 
Redstem filaree (Stork's bill, Crane's bill) 
Reed canarygrass 
Russian thistle (Tumbleweed) 
Ryegrass, annual (Italian ryegrass) 
Salsify (Goatsbeard) 
Scotch broom 
Shepherd's-purse 
Smartweeds 
Sowthistle, annual and perennial 
Speedwells 
Spurges (Prostrate spurges) 
St. Johnswort, common (Goatweed, Klamathweed) 
Stinging nettle 
Tansy ragwort 
Tumblemustard (Jim Hill mustard) 
Velvetgrass (Common velvetgrass) 
Velvetleaf 
Water primrose 
Waterhemlock, western 
Yellow nutsedge 



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Caption: Spiny sowthistle
Photo by: T. W. Miller
  
Weeds : Sowthistle, annual and perennial : Sonchus oleraceus, Sonchus arvensis
(revision date: 5/31/2016)

Family: Asteraceae (Compositae)
Cycle: Annual
Plant Type: Broadleaf

Use Integrated Pest Management (IPM) for successful weed management.

Biology
Annual sowthistle grows upright and can reach from one to four feet tall. The lower leaves have a stalk while the upper leaves do not. Most of the leaves are deeply lobed and have one to three lobes on each side. Annual sowthistle produces many pale yellow flower heads that are 1/4 to 3/4 inch wide. The seeds are flat with lengthwise ribs and a parachute-like tuft of fine hairs that aid in wind dissemination. Perennial sowthistle leaves, stems, and flowerheads are often a little larger than annual sowthistle. Perennial sowthistle produces many creeping roots that aid the spread of this creeping perennial species.
Habitat
Sowthistle grows along roadsides, cultivated fields, in gardens and in waste areas throughout Washington.

Management Options

Non-Chemical Management
None recommended
Select non-chemical management options as your first choice!

Chemical Management

Glyphosate products should be applied as spot treatments only! NOTE: Some ingredients listed here are only available in combination. Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas
    Turf areas
    • 2,4-D + MCPP + dicamba
    Bare ground areas
    • glyphosate
    Images

    + Show larger images

     
    Caption: Spiny sowthistle
    Photo by: T. W. Miller
    Caption: Perennial sowthistle glandular hairs
    Photo by: T. W. Miller
    Caption: Annual sowthistle flower heads
    Photo by: T. W. Miller
    Caption: Annual sowthistle leaf at base of stem
    Photo by: J.A. Kropf
    Caption: Line drawing of annual sowthistle
    Photo by: Ciba Geigy
    Caption: Annual sowthistle flower
    Photo by: T. W. Miller
    Caption: Annual sowthistle
    Photo by: C.R. Foss
    Caption: Annual sowthistle mature head
    Photo by: T. W. Miller