Cranberries grow on trailing vines in soil composed of sand, gravel, peat and clay during the growing season, but they do not grow in water. Growers flood the crop in autumn, which enables the easy gathering of the fruit, and they flood the beds in winter to protect the plants from low temperatures.
Cranberry vines produce long runners and live for many years. In Massachusetts, some vines are over 150 years old. They require a growing season from April through November, fresh water and a particular combination of soils, and they grow in acidic wetlands called bogs, which are rich in organic material. Growers spread a layer of sand in cranberry bogs every three years to encourage growth and deter insects and weeds. A dyke system controls water and allows drainage during the growing season.
The cranberry harvest occurs from September through November, and during this time, cranberry growers flood the beds with water over the height of the vines. A harvester removes the fruit from the vine and gathers it while it floats on the water. A small percentage of cranberries are dry picked, which yields less and costs more in labor, but it produces unbruised fruit to sell fresh. About 95 percent of cranberries become juice and sauce, while the remainder are dried. They grow commercially in New Jersey, Massachusetts, Wisconsin, Oregon and Washington.