According to observations of naturalists and beekeepers.
Where are you?
30 kilograms per ha
SOURCE FOR HONEY BEES:
Major in some areas
California blackberry grows from British Columbia to northern California and eastward to central Idaho. It is particularly common from the Cascades to the Pacific Coast. California blackberry extends through southern California into Mexico. The subspecies macropetalus occurs from British Columbia and Idaho southward into northern California.
Rubus ursinus is a wide, mounding shrub or vine, growing to 2–5 feet (0.61–1.52 m) high, and more than 6 feet (1.8 m) wide. The prickly branches can take root if they touch soil, thus enabling the plant to spread vegetatively and form larger clonal colonies. Leaves usually have 3 leaflets but sometimes 5 or only 1, and are deciduous. The plant is dioecious, with male and female plants on separate plants, also unusual for the genus. As with other Rubus, the canes are typically vegetative the first year and reproductive in the second. Flowers are white with narrower petals than most related species and have a fragrance. The sweet, very aromatic, edible fruits are a dark purple, dark red, or black and up to 2 centimeters (0.8 inches) in length.
Seasonal development of the California blackberry varies according to geographic and climatic factors.
Flowering Time: Late Spring, Early Summer.