Blueberry plants and blackberry plants have much in common. They both produce edible berries, high in antioxidants and stuffed with vitamins and nutrients. They are quite different plants, however, and in order to grow the berry variety that best fits your needs and growing conditions you must know the difference between the two.
Blackberries grow either erect, semi-erect or as a vine. The semi-erect and vine varieties sometimes need a trellis for support, but will also grow up and over other plants if left wild. Some varieties of this plant have thorns. Blueberries only grow erect as a shrub and are always thorn-less.
Blueberries are small and round, changing from a green color in youth to dark blue color when ripe. Blackberries have a more oblong shape and turn from a red to a dark purple or black color when ripe. Blackberries are what you call an "aggregate fruit," which means that each berry contains smaller berry segments gathered together. Each blueberry is one spherical fruit.
Blueberries thrive on acidic soil, with a pH between 4.0 and 4.5. They do not do well otherwise. Most of the time, at planting and after planting, you must amend the soil to attain the right pH. Blackberries will grow in any type of soil as long as it is well-drained, although they grow best in soil high in organic matter with a pH between 6.0 and 6.5.
A cup of blackberries is 62 calories and 42 mg of calcium while a cup of blueberries is 83 calories and 9 mg of calcium. Blueberries rank number one in antioxidants, but a 2006 study by scientists of the U.S. Agricultural Research Service show that blackberries have compounds that may be more effective in fighting cancer.