Blueberry plants (Vaccinium species) are known primarily for their fruit, which grow on the bush as clusters of small, round, black to blue fruit. Cultivated fruit bushes are mainly highbush blueberries (Vaccinium corymbosum), which are grown in home gardens and in commercial orchards. Lowbush blueberries (Vaccinium angustifolium), while grown commercially in some areas, are known primarily for their value as wild blueberries.
Lowbush and highbush blueberries grow in moist, well-drained soils of high acidity (pH from 4.5 to 5.5), often occurring on stream banks and near ponds or lakes. Ranging from Virginia to Maine and west to Minnesota and Illinois, most native varieties of blueberries can be found growing in open fields and forests with somewhat sandy or peaty soils. Lowbush blueberries also grow on rocky outcrops in poor soils.
Blueberry Plant Form
As the name implies, highbush blueberries can grow to be quite tall, 10 or more feet in height, and if left unpruned can be dense from the multitude of branches that emerge from the base. Near the base of the shrub, the bark of the branches usually has a shredded appearance. Older branches are reddish-gray in color, while new stem growth is green in its first year. Branches have an open, loose appearance.
Lowbush blueberries have a more compact growth habit, generally growing not more than 2 feet tall and wide. In other respects, the stems resemble their taller cousins, with papery bark near the base and a loose, open, multi-stemmed habit.
Blueberry Leaf Identification
Though highbush blueberry leaves are larger than lowbush leaves, both plants feature pointed oval-shaped (lanceolate) leaves arranged alternately on the branch. The undersides of leaves are glaucous, or whitish-gray in color, and in the autumn, blueberry foliage turns a deep, bright red. As a deciduous shrub, blueberries lose their leaves through the winter, but new foliage emerges in the spring just after blossoming begins.
In mid- to late spring, blueberry bushes produce clusters of small, white bell- or urn-shaped flowers that then develop into clusters of fruit in early to midsummer. Bees and other insects pollinate the flowers, and in home garden settings, plants generally require at least one other nearby bush for successful pollination.
Though cultivars and regional differences account for variations in fruit size, most blueberry fruits are between ¼ and ½ inches across and dusky blue. Berries often have a "bloom," or powdery appearance that rubs away when the berries are handled. Unripe fruits progress from green to pink to light purple, which then ripen into the familiar dark blue to almost black color. The fruits contain several dozen tiny edible seeds.