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: Orange hawkweed flowerheads
Photo by: T.W. Miller
  
Weeds : Hawkweeds : Hieracium spp.
(revision date: 6/9/2016)

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

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

Biology
Hawkweeds are fibrous rooted perennial herbs that grow up to a foot tall. The leaves are basal, with an occasional leaf or two on stems. The bristly, leafless, flower stalks rise above the basal clump of leaves. The plants contain milky juice. They typically have five to thirty flower heads, and each flower has notched upper margins. Flowers may be yellow (yellow hawkweed) or red-orange (orange hawkweed). While mouseear hawkweed stalks typically bear a single yellow flower head (giving a dandelion-like appearance), the orange and yellow hawkweeds may bear several flower heads. These species spread by seed and creeping stolons which root into the soil. There are numerous species of hawkweeds. As they interbreed freely, it can be extremely difficult to identify them to a species level. SPECIAL INFORMATION: Depending on species, non-native hawkweeds are designated as Class 'A,' 'B,' or 'C' noxious weeds in WASHINGTON. Eradication or management of these species may be REQUIRED by law in your county. In OREGON, 5 species are designated as Class 'A' noxious weeds and three are target or 'T' weeds subject to priority prevention and control. Eradication or intensive control may be required in your county. In addition, several non-native hawkweeds are on the noxious weed quarantine list for both Washington and Oregon. Sale, purchase, and transport of plants, plant parts, and seeds is prohibited. Consult your local Noxious Weed Control Board for more information.
Habitat
Hawkweeds are found mostly in northeastern Washington, though several species may have limited distribution throughout much of the state. Yellow, orange, mouseear, and yellow devil hawkweeds can also be found west of the Cascades. Hawkweeds prefer coarse, well-drained soils in full sun to partial shade and are often found on roadsides, or in fields, pastures, or disturbed areas.

Management Options

Non-Chemical Management
  • Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label instructions. Use glyphosate products as spot treatments only! Not a problem in healthy established turf. 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
  • glyphosate
Turf areas
  • 2,4-D + MCPP + dicamba
Bare ground areas
  • glyphosate
Images

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Caption: Orange hawkweed flowerheads
Photo by: T.W. Miller
Caption: Orange hawkweed roadside
Photo by: T.W. Miller
Caption: Meadow hawkweed flowerheads
Photo by: T.W. Miller
Caption: Meadow hawkweed plants
Photo by: T.W. Miller
Caption: Orange hawkweed flowers
Photo by: Washington Noxious Weed Board slide collection
Caption: Orange hawkweed
Photo by: D.G. Swan
Caption: Yellow hawkweed flowers
Photo by: Washington Noxious Weed Board slide collection