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: Crabgrass
Photo by: R. Parker
  
Weeds : Crabgrass : Digitaria spp.
(revision date: 8/13/2015)

Family: Poaceae (Graminae)
Cycle: Annual
Plant Type: Grass

Biology
Large crabgrass (Digitaria sanguinalis) may reach up to two feet tall but is often prostrate. Stems lying along the ground may root, forming mats. The flat leaf blades are relatively broad (1/4 to 1/2 inch wide), two to five inches long, and sometimes hairy. Leaf sheaths are hairy and often purplish, and auricles are absent. Ligules, which are found around the stem at the junction of the leaf blade and leaf sheath, are membranous, tall, and have jagged edges. Smooth crabgrass (D. ischaemum) is similar to large crabgrass in habit, but leaves are more slender and are not as hairy. This species is prostrate and may form mats. Seeds of both species are borne on slender, finger-like whorls of spikes two to six inches in length. They resemble Bermudagrass (Cynodon dactylon) seed heads, but crabgrass seed spikes do not all arise from one junction at the top of the stem.
Habitat
Crabgrasses are weedy in waste places, cultivated areas, lawns, and other sites, commonly on light soils.

Management Options

Non-Chemical Management
  • Cultivation (rototilling or hoeing) will effectively eliminate plants.
Select non-chemical management options as your first choice!

Chemical Management

Summer annual grasses are rarely a problem in western Washington; no herbicides are recommended. In lawns, keeping the grass dense to crowd out crabgrass is the best defense. Cultivation in lawns is not a practical option. Conversely, preemergent herbicides are very effective in controlling crabgrass in eastern Washington; apply in spring when soil temperatures reach 50 to 55 degrees F. (usually about the time forsythia bloom). There are several postemergent products, which can be applied by a licensed professional for control. Glyphosate and glufosinate 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
  • glyphosate
  • dichlobenil
  • glufosinate
  • trifluralin
  • sethoxydim
  • fluazifop
Turf areas
  • products containing benefin
  • pendimethalin
  • benefin, trifluralin
Bare ground areas
  • glyphosate
Images

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Caption: Crabgrass
Photo by: R. Parker
Caption: Line drawing of crabgrass
Photo by: Ciba Geigy
Caption: Multiple crabgrass seed heads
Photo by: T.W. Miller
Caption: Crabgrass hairy leaves
Photo by: T. W. Miller
Caption: Crabgrass seedheads
Photo by: T. W. Miller