Cranberry

Cranberries are evergreen dwarf shrubs or trailing vines that belong to the subgenus Oxycoccus within the genus Vaccinium. These low-growing plants reach lengths of up to 2 meters and heights of 5 to 20 centimeters, with thin, wiry stems and small, persistent leaves. Their dark pink flowers have petals that curve back, exposing the style and stamens, and are pollinated by bees. The fruit is a berry larger than the leaves, starting light green and maturing to red, with a sour flavor that typically overpowers any sweetness.

In Britain, the term cranberry often refers to the native species Vaccinium oxycoccos, while in North America it usually means V. macrocarpon. The former is grown in central and northern Europe, the latter across the northern United States, Canada, and Chile.

Products

In 2020, these three countries produced 97% of the world’s cranberries. Most of the harvest is turned into juice, sauce, jam, or sweetened dried cranberries; the rest is sold fresh. Cranberry sauce is a traditional side for turkey at Christmas and Thanksgiving dinners in the U.S. and Canada, and at Christmas dinners in the United Kingdom.

Similar species

Cranberries are related to bilberries, blueberries, and huckleberries, which have bell-shaped flowers with unreflexed petals and woodier stems that form taller shrubs. In some classification systems, Oxycoccus is treated as its own genus. There are four to five cranberry species, grouped under subgenus Oxycoccus and its section Oxycoccoides.

Etymology

The name cranberry comes from the Middle Low German word for craneberry, first recorded in English by missionary John Eliot in 1647. Around 1694, German and Dutch colonists in New England used the term because the flower, stem, calyx, and petals resembled the neck, head, and bill of a crane. The traditional English name for the European species, fenberry, came from plants with small red berries found in English fenlands.

Cranberries grow in acidic bogs across the cooler regions of the Northern Hemisphere. American Revolutionary War veteran Henry Hall first cultivated them around 1816 in Dennis, on Cape Cod. By the 1820s, he was shipping berries to New York City and Boston, with some shipments reaching Europe.

Cultivation

In 1843, Eli Howes planted the “Howes” variety on Cape Cod, and in 1847, Cyrus Cahoon planted “Early Black” near Pleasant Lake, Harwich, Massachusetts. By 1900, 21,500 acres were under cultivation in New England. In 2021, the U.S. harvested 790 million pounds of cranberries, with Wisconsin leading (59% of the total), followed by Massachusetts, New Jersey, and Oregon.

Two major breeding efforts shaped modern cranberries. The first, in the 1920s, aimed for insect resistance—specifically against the blunt-nosed leafhopper, which spreads cranberry false blossom disease. This produced cultivars like “Stevens” and “Franklin,” while older ones like “Howes” remained more susceptible.

After broad-spectrum pesticides became common in the 1940s and 1950s, breeders stopped focusing on pest resistance. Starting in the 1980s, they shifted to high-yielding varieties, such as “Crimson Queen” and “Mullica Queen,” many developed by Dr. Nicholi Vorsa at Rutgers University. Recently, tighter pesticide restrictions have renewed emphasis on varieties that combine high yield with strong resistance.

Historically, cranberry beds were built in wetlands. Today, they are constructed in upland areas with a shallow water table. Topsoil is removed to create dykes around the bed, then clean sand is spread 10 to 20 centimeters deep and laser-leveled for even drainage.

Beds are drained with socked tile and perimeter ditches. Dykes allow water retention and let equipment service the beds without driving on the vines. Irrigation systems provide water for growth and frost protection in spring and autumn. Contrary to common belief, beds are not flooded year-round.

During the growing season, they are only irrigated to maintain soil moisture. Flooding occurs in autumn to help with harvest and again in winter to protect against cold. In cold climates like Wisconsin, New England, and eastern Canada, the winter flood freezes into ice; in warmer areas, it stays liquid.