According to observations of naturalists and beekeepers.
Where are you?
30 kilograms per ha
SOURCE FOR HONEY BEES:
Major in some areas
The cutleaf blackberry is a native of Eurasia which has become widely naturalized in North America. It now occurs through much of the Northwest, from British Columbia to northern California west of the Cascades and eastward to Idaho. Cutleaf blackberry also grows throughout much of New England, extending westward to Michigan and southward to the Middle Atlantic States. It is locally established in parts of Montana, Wyoming, and Colorado. It is cultivated in Hawaii.
This plant is present in at least 30 states/provinces in this country.
Cutleaf blackberry is a semi-erect to erect and arching, much-branched shrub which grows up to 10 feet (3 m) in height. These shrubs often grow in a dense cluster. Stems often trail at the ends and are covered with numerous stout, curved thorns.
The stems of blackberries are generally biennial. Sterile first-year stems, known as primocanes, develop from buds at or below the ground surface and produce only leaves. Lateral branches, or floricanes, develop in the axils of the primocanes during the second year and bear both leaves and flowers.
Cutleaf leaves have five leaflets and are palmately or, less commonly, pinnately compound. Leaves are green on both surfaces, but hairy beneath. Leaflets are lacinate to dissected.
Perfect white-to-pink or rose flowers are borne in compound paniculate cymes. Fruit of the cutleaf blackberry is large, round, and shiny black in color. Fruit grows up to 0.8 inches (2 cm) in length and is made up of a few large, sweet, succulent drupelets.
Cutleaf blackberry is primarily regarded as an early seral species. It has been reported on initially disturbed and early immature stands in coniferous forests of southwestern British Columbia. Cutleaf blackberry is also abundant in old-field communities and on disturbed sites in the Northeast.
Seasonal development of the cutleaf blackberry varies according to geographic location and climatic factors.
Salix bebbiana (aka: Bebb willow, Beak willow, Beaked willow, Long-beaked willow, Diamond willow, Chaton, Petit Minou, Smooth Bebb willow)
Rhus glabra (aka: Smooth sumac, Common sumac, Rocky Mountain sumac, Red sumac, Western sumac, White sumac)
Allium schoenoprasum (aka: Chives)
Brassica napus (aka: Rapeseed)
Sinapis arvensis (aka: Charlock mustard, California rape, Charlock, Corn mustard, Canola, Kaber mustard, Rapeseed mustard)
Asclepias tuberosa (aka: Butterflyweed, Butterfly Milkweed, Orange Milkweed, Pleurisy Root, Chigger Flower, Canada root, Fluxroot, Indian paintbrush, Indian posy, Orange root, Orange Swallow-wort, Tuber root, Yellow milkweed, White-root, Windroot, Butterfly love)
Asclepias syriaca (aka: Сommon milkweed, Butterfly flower, Silkweed, Silky swallow-wort, Virginia silkweed)
Brassica rapa (aka: Field mustard, Common mustard, Wild mustard, Wild turnip, Forage turnip, Wild rutabaga, Birdsrape mustard, Rape mustard)
Echium vulgare (aka: Viper's bugloss, Blueweed, Blue thistle)
Rubus laciniatus (aka: Cutleaf blackberry, Evergreen blackberry, Slashed blackberry)
Salsola kali (aka: Russian thistle, Tumbleweed, Prickly saltwort)
Borago officinalis (aka: Borage, Starflower, Common borage, Cool-tankard, Tailwort)
Citrullus lanatus (aka: Watermelon)
Cephalanthus occidentalis (aka: Common buttonbush, Buttonball, Buttonbush, Button willow, Riverbush, Honey-bells)
Cirsium arvense (aka: Creeping Thistle, Canada thistle, Field thistle, California thistle, Lettuce from hell thistle, Corn thistle, Cursed thistle, Green thistle, Hard thistle, Perennial thistle, Prickly thistle, Small-flowered thistle, Way thistle, Stinger-needles)
Hyssopus officinalis (aka: Hyssop)
Calluna vulgaris (aka: Heather, Scotch heather, Common heather, Ling, Simply heather)