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: Garden loosestrife, flowering
Photo by: King County Noxious Weed Control Program
  
Weeds : Garden loosestrife : Lysimachia vulgaris
(revision date: 6/9/2014)

Family: Primulaceae
Cycle: Perennial
Plant Type: Broadleaf

Biology
Garden loosestrife is an erect rhizomatous perennial that may attain a height of three feet or more. Both stems and leaves are soft and hairy to the touch. Lance-shaped leaves, 3 to 5 inches long, emerge from the stem in an opposite or whorled arrangement. The leaves are dotted with orange or black glands. The yellow, primrose-like flowers occur in a cluster at the top of the plant. Each flower has five petals and a calyx with reddish-brown margins. The fruit is a dry capsule-like body. Garden loosestrife spreads by both seeds and rhizomes. SPECIAL INFORMATION: The ability of garden loosestrife to invade and establish itself in wetlands threatens native plant communities. In spite of its more recent introduction, observations indicate garden loosestrife is far more abundant and appears to be outcompeting purple loosestrife. Therefore, in WASHINGTON, garden loosestrife is designated as a Class 'B' noxious weed and is also on the wetland and aquatic weed quarantine list. Sale, purchase, and transport of plants, plant parts, and seeds is prohibited. Management may be required by law in your county. Consult your local Noxious Weed Control Board for more information.
Habitat
Garden loosestrife occurs in moist habitats, such as fens, wet woods, lake shores, and river banks. It has also been planted as an ornamental and used for landscaping purposes, while admirers remain unaware of its invasive capability.

Management Options

Non-Chemical Management
  • Hand-pull to eliminate weeds.
  • Inorganic mulches, such as plastic, commercial "weed barrier" fabrics and other materials such as roofing paper, is an effective weed management option. Cover inorganic mulches with a thin layer of soil or organic mulch.
  • Digging and carefully removing all rhizomes will effectively eliminate single plants and small infestations.
Select non-chemical management options as your first choice!

Chemical Management

Digging and handpulling is effective on very small populations only. Applications should be made by those holding a current aquatic pest control license. In Washington, a special permit is required for use of herbicides in aquatic sites. Contact the Washington Department of Ecology or the Washington State Noxious Weed Control Board for more information.

Images

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Caption: Garden loosestrife, flowering
Photo by: King County Noxious Weed Control Program