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: Liverworts in pot
Photo by: J. Altland
  
Weeds : Liverworts : Several species
(revision date: 9/3/2015)

Family: Various
Cycle:
Plant Type: Bryophyte (mosses & liverworts)

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

Biology
Liverworts are low-growing, non-flowering relatives of mosses. They are typically small plants that grow prostrate on the ground. Lacking true roots, they are attached to the soil or other growing surface by rhizoids, which are colorless, hair-like structures. The green parts of some species may be a ribbon-like or wavy thallus, while other species may be lobed or even divided into two or three rows of "leaves." Liverwort plants may be up to 1 inch wide and can grow to 10 inches in length under good conditions. Liverworts, like mosses, reproduce by spores rather than seeds. The spores are produced in tiny capsules which protrude from the upper surface of the thallus, splitting open to scatter the spores when they are mature. Some liverworts also reproduce asexually by structures called gemmae, which may be produced inside cup-like structures on the top surface of the thallus. Gemmae are often spread by splashing water. SPECIAL INFORMATION: Some liverworts are reported to have a spicy scent due to the volatile oils they produce. This scent may deter animals from eating them. Liverworts can become significant pests in container-grown plants and nursery stock.
Habitat
Liverworts thrive in moist, humid environments, but some species are also able to survive in drier sites. They usually occur on damp soils, rotting logs, stream banks, or other moist sites, but may also become a nuisance in landscapes. In the Pacific Northwest, liverworts are most likely to be a landscape problem from early fall to late spring, when they are favored by cool, damp weather conditions.

Management Options

Non-Chemical Management
  • Weather plays a large role in control of liverworts. Hot, dry conditions will slow their growth.
  • Do not overwater. When possible, allow the soil surface to dry between waterings. Avoid overhead irrigation where liverworts are a problem.
  • Do not apply excess fertilizer, as liverworts thrive in high-nutrient environments.
  • Mulch problem areas with durable materials that drain well and dry quickly at the surface. Examples include coarsely crushed hazelnut shells, crushed oyster shells, or fabric-type weed barriers.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label instructions. 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
  • potassium laurate
Turf areas
  • potassium laurate
  • iron HEDTA
Bare ground areas
  • potassium laurate
Images

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Caption: Liverworts in pot
Photo by: J. Altland
Caption: Liverworts
Photo by: T. W. Miller
Caption: Liverworts
Photo by: T. W. Miller