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Hortsense Home| Hortsense fact sheets | Weeds | Prostrate knotweed

Weeds

Annual bluegrass

Bentgrass, creeping

Birdfoot Trefoil

Bittercress (Shotweed, Hairy bittercress)

Bittersweet nightshade (European bittersweet)

Blackberry (Himalayan, Evergreen, Pacific)

Blue mustard (Purple mustard, Tenella mustard)

Brackenfern, western

Buttercup, creeping

Catchweed bedstraw (Cleavers)

Catsear, common (False dandelion)

Chickweed, common and mouseear

Dock (Curly, Broadleaf)

Downy brome (Cheatgrass, Downy chess)

Dwarf mistletoes

English daisy (Lawn daisy)

Field bindweed (Wild morningglory)

Field pennycress (Fanweed)

Foxtail (Green, Yellow, Bristly)

Garden loosestrife

Groundsel, common

Herb Robert (Robert geranium, stinky Bob)

Horsetails (Scouringrush)

Horseweed (Marestail)

Knotweeds (Bohemian, Giant, Japanese, Himalayan)

Lambsquarters, common

Lesser celandine

Mallow, common (Cheeseweed, Buttonweed)

Oxalis (Creeping woodsorrel)

Parrotfeather and Eurasian watermilfoil

Plantain (Broadleaf, Buckhorn)

Poison ivy and Poison oak

Prickly lettuce (China lettuce)

Prostrate knotweed

Puncturevine (Tackweed, Goathead)

Purple deadnettle (Red deadnettle)

Purple loosestrife (Purple lythrum)

Purslane, common

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)

Shepherd's-purse

Sowthistle, annual and perennial

Spurges (Prostrate spurges)

St. Johnswort, common (Goatweed, Klamathweed)

Stinging nettle

Tumblemustard (Jim Hill mustard)

Velvetgrass (Common velvetgrass)

Waterhemlock, western

Wild carrot (Queen Anne's lace)

Yellow nutsedge

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Caption: Prostrate knotweed leaves

Photo by: R. Parker

Weeds : Prostrate knotweed : Polygonum aviculare

(revision date: 4/7/2021)

Family: Polygonaceae
Cycle: Annual
Plant Type: Broadleaf

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

Biology

Prostrate knotweed is a low-growing plant with wiry stems and a thin taproot. Plants branch extensively at the base, with branches lying along the ground but not rooting. The alternate, blue-green leaves are narrow, typically not exceeding an inch in length and 1/4 inch in width. Leaf tips may be slightly pointed to rounded in outline. The petioles are very short. The greenish-white flowers are borne in leaf axils and are inconspicuous.

Habitat

Prostrate knotweed is commonly found on compacted soils and may occur on waste areas, or in lawns, paths, and other areas in yards. It is frequently a problem on compacted or high-traffic areas in lawns.

Management Options

Non-Chemical Management

Cultivation (rototilling or hoeing) will effectively eliminate plants.

Select non-chemical management options as your first choice!

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

Apply according to label directions. 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

glyphosate
dichlobenil
trifluralin
products containing diquat

Turf areas

2,4-D + MCPP + dicamba

Bare ground areas

glyphosate
products containing diquat
dichlobenil

Images

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Caption: Prostrate knotweed leaves Photo by: R. Parker
Caption: Prostrate knotweed Photo by: R. Parker
Caption: Prostrate knotweed flowers and leaf axils Photo by: D.G. Swan
Caption: Prostrate knotweed seedling Photo by: J.A. Kropf
Caption: Prostrate knotweed growing in gravel Photo by: T.W. Miller
Caption: Prostrate knotweed flowers and nodes Photo by: T. W. Miller
Caption: Prostrate knotweed leaves Photo by: T. W. Miller