Cranberries grow on low-lying vines in impermeable beds layered with sand, peat, gravel and clay. These beds are known as “bogs” or “marshes” and were originally created by glacial deposits. Commercial bogs use a system of wetlands, uplands, ditches, flumes, ponds and other water bodies that provide a natural habitat for a variety of plant and animal life. Cranberries are harvested in the fall, generally from mid-September through mid-November.
Growing & Harvest
Bogs and marshes are flooded to create a layer of ice that protects vines from harsh weather. The ice also allows for sanding of the beds, which stimulates growth when the ice melts.
Bogs and marshes are drained and blossoms appear for bees to pollinate. Growers monitor for frost and insects.
Petals fall from the flowers, leaving small green nodes that will turn into cranberries. Growers irrigate as necessary and monitor fruit quality.
Berries achieve size and color and are harvested using wet or dry methods. Beds begin to go dormant after harvest and growers begin off-season maintenance work.
Most cranberries are wet harvested when growers flood their bogs and use harvesting machines that loosen the cranberries from the vine. Four air chambers in the cranberry’s center allows it to float to the water’s surface. The berries are then corralled and transferred to a truck for transport.
While only a small percentage of cranberries are dry harvested, the process can be done by hand or using mechanical pickers resembling lawn mowers with comb-like conveyor belts that carry the berries to attached burlap bags.
Wisconsin grows 65% of the cranberries in the US while Massachusetts accounts for another 23%.
Cranberry Bogs & Marshes
Cranberries are grown throughout the northern part of the United States – Wisconsin, Massachusetts, Oregon, New Jersey and Washington primarily. These areas offer the special conditions that cranberries require including sandy soil, abundant fresh water and a growing season from May to October. Wisconsin grows 65% of the cranberries in the US while Massachusetts accounts for another 23%. New Jersey, Oregon and Washington state combine to make up the remaining 12%.
The American cranberry, Vaccinium Macrocarpon Ait., is a native berry to North America. The European species, Vaccinium Oxycoccus L., has never been cultivated in North America and has a smaller fruit which is often speckled. Because V. oxycoccus is a tetraploid species (the plant has twice as many chromosome sets as normal often resulting in large plants and flowers), it will not hybridize with the diploid, V. macrocarpon. Research on cranberries has primarily been conducted using the V. macrocarpon variety.
There are more than 100 varieties of cranberries that grow in North America.
Popular Cranberry Varieties
Discovered by D. R. Burr in 1900 in Berlin, Wisconsin, this variety represents 11% of Wisconsin acreage. The Ben Lear variety develops color in early-mid September.
Discovered by A. Searles in 1893 in Wisconsin Rapids, Wisconsin, this variety represents 17% of acreage in Wisconsin.
Discovered by T. H. McFarlin in 1874 in S. Carver, Massachusetts, this variety represents 11% of Wisconsin acreage and 54% of Washington acreage.
Discovered by E. Howes in 1843 in East Dennis, Massachusetts, Howes are harvested about three weeks after the Early Blacks. Howes produce bigger, firmer, tart berries and they store well. Howes can be sliced and still hold their berry shape. This variety represents 36% of acreage in Massachusetts.
Discovered by N. Robbins in 1852 in Harwich, Massachusetts, they are the first berries to market in September. Growers like them because they can be harvested before the fall frost season. The berries are smaller and yield less than new hybrids but have a sweeter taste and intense red color. This variety represents 43% of acreage in Massachusetts and 55% in Oregon, New Jersey, and Washington.
Discovered by H. F. Bain in 1940 in Whitesbog, New Jersey, this variety dominates in the largest growing region of the country, accounting for 51% of the acreage. Stevens also accounts for 12% of acreage in Massachusetts and 75% of acreage in Oregon.