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: Blackberry fruit
Photo by: T. W. Miller
  
Weeds : Blackberry (Himalayan, Evergreen, Pacific) : Rubus spp.
(revision date: 10/14/2016)

Family: Rosaceae
Cycle: Perennial
Plant Type: Broadleaf

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

Biology
Several species of blackberries may be considered weeds. Among these are evergreen or cutleaf blackberry (Rubus laciniatus), the native dewberry or Pacific blackberry (R. ursinus), and Himalayan blackberry (R. armeniacus, also known as R. discolor or R. procerus). Evergreen blackberry is less robust than Himalayan blackberry, with evergreen leaves that are green on both upper and lower surfaces and somewhat hairy on the undersides. The leaves are divided into pointed, sharply toothed and lobed leaflets. Stems are armed with large prickles. Dewberry has slender, trailing stems lightly armed with slender prickles. Unlike the other species mentioned here, dewberry leaves have only three leaflets. The leaflets are oval and pointed with slightly toothed margins. Himalayan blackberry is a large, aggressive plant with robust canes reaching up to nearly an inch in diameter. The canes are armed with strong, backwards-curving prickles, as are the main veins of the leaves. Leaves consist of five leaflets and are grayish on the undersides. In western Washington, leaves may persist through the winter. Long canes arch 10 feet or more over obstacles and will root to establish new plants where the cane tips contact the ground. Plants produce white to pale pink flowers in the summer, with reddish-purple to black fruits ripening in late summer. SPECIAL INFORMATION: In WASHINGTON, Himalayan blackberry (R. armeniacus) and evergreen blackberry (R. laciniatus) are designated as Class 'C' noxious weeds. In OREGON, Himalayan (Armenian) blackberry (R. armeniacus) is designated as a Class 'B' noxious weed and is also on the Oregon noxious weed quarantine list, which prohibits sale, purchase, and transport of plants, seeds, and plant parts except fruit intended for consumption. Management may be required by law in your county. Consult your local Noxious Weed Control Board for more information.
Habitat
Blackberries are found on various sites including roadsides, clearings or burned areas in woodlands, pastures, and many other areas. They are most typically a problem west of the Cascades, where they are widely established. However, they are not usually a problem in maintained lawn and turfgrass.

Management Options

Non-Chemical Management
  • Cultivation (rototilling or hoeing) will effectively eliminate plants.
  • Mowing to prevent seed production is a very effective means of management. In lawns, mowing regularly at the proper height for the grass species may help minimize weed growth and invasion.
  • 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 glyphosate products in September to October when canes still have foliage and after berries are formed. Fall treatment must be made before a killing frost. Triclopyr products are effective and are available for non-specific area application. Glyphosate products should be applied as spot treatments only! Herbicides should be used with caution if the fruit may be eaten. 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
    Bare ground areas
    • glyphosate
    • triclopyr
    Images

    + Show larger images

     
    Caption: Blackberry fruit
    Photo by: T. W. Miller
    Caption: Himalayan blackberry leaflets
    Photo by: T. W. Miller
    Caption: Evergreen blackberry
    Photo by: T.W. Miller
    Caption: Evergreen blackberry leaflets
    Photo by: T.W. Miller
    Caption: Mix of evergreen and Himalayan blackberries
    Photo by: T.W. Miller
    Caption: Pacific blackberry
    Photo by: T.W. Miller
    Caption: Pacific blackberry
    Photo by: T.W. Miller
    Caption: Blackberry flowers and leaves
    Photo by: T.W. Miller
    Caption: Established blackberry clumps
    Photo by: J.A. Kropf
    Caption: Blackberry flower
    Photo by: T. W. Miller