According to observations of naturalists and beekeepers.
Where are you?
SOURCE FOR HONEY BEES:
Minor in most areas
Lowbush blueberry grows from Labrador and Newfoundland westward to southern Manitoba and Minnesota. It extends southward to northern Illinois in the West, and from New England through the Appalachians to West Virginia and Virginia in the East.
Lowbush blueberry is an important recolonizer. Its sprouts are prominent on disturbed sites such as clearcuts, burns, fields, and pastures. Cover is typically higher on fields derived from hayfields than those derived from woodlots. Lowbush blueberry is an important seral species during the transition from field to forest in various eastern old-field communities.
Vaccinium angustifolium is a low spreading deciduous shrub growing 5 to 60 cm (2 to 24 in) tall. Its rhizomes can lay dormant up to 100 years, and when given the adequate amount of sunlight, soil moisture, and oxygen content they will sprout. The leaves are glossy blue-green in summer, turning a variety of reds in the fall. The leaf shape is broad to elliptical. Buds are brownish red in stem axils. The flowers are white, bell-shaped, 4 to 6 mm (0.16 to 0.24 in) long. The fruit is a small sweet dark blue to black berry, full of antioxidants and flavonoids. This plant grows best in wooded areas, old abandoned farmyards or open areas with well-drained acidic soils.
Phenological development of lowbush blueberry varies according to geographic location and specific weather conditions. Temperature and day length are important regulatory influences. Initial floral development begins in the year before flowering and fruiting. Floral bud primordia appear during June and early July when day length reaches approximately 15 hours. Development may continue until late October if air temperatures remain above 32 degrees Fahrenheit (0 deg C) with long periods above 50 degrees Fahrenheit (10 deg C). Leaves harden by mid-July, color by late August, and abscise by late October.
Plants generally flower in May or June of their 2nd year. A few flowers may open as early as March in unusually good years, and some plants occasionally flower as late as September or October. Flowering may be delayed by 2 or 3 weeks in cool, coastal areas. Fruit generally ripens from midsummer to late summer, approximately 50 days after anthesis.