The cranberry is a slender, trailing native North American shrub (Vaccinium macro-carpon) that grows in moist, sandy soil. The fruit berry is small, red, quite tart, and high in vitamin C. The berries are used either fresh or in processed foods such as juices, jams, and jellies. Vines are planted in sandy, peat-rich soil that is acidic and often flooded with water for more efficient harvesting. Cranberries grow wild in the northern climes of North America. The cranberry is one of only three fruits native to North America, the blueberry (Vaccinium angustifolium and V. corymbosum) and the Concord grape (Vitaceae lubrusca) being the other two. There are about 1,200 cranberry growers in North America and cultivation occurs only in Massachusetts, Wisconsin, New Jersey, Oregon, and Washington State. Today, at least 200 billion cranberries are harvested each year and the annual sales exceed $1.5 billion dollars. Of that, Ocean Spray Cranberry Growers Cooperative markets 90% of the annual yield in the United States.
Because cranberries are an indigenous fruit, the Native Americans used them in a number of ways—fresh, ground, and mashed and baked with cornmeal. They mixed dried cranberries with dried meats and melted fat to make pemmican—a survival food for winter. Cranberry poultices, medicinal teas, and dyes were also used. European settlers thought the flower of the cranberry vine resembled the crane's head—hence the name cranberry—and used them extensively by 1700. Sailors used them to stave off scurvy because of their high vitamin C content.
Commercial cranberry production began in Cape Cod in 1815 and early commercial producers picked cranberries by hand. Cultivated throughout the nineteenth century in the East as well as the Midwest, individual growers often devised their own innovative machinery to meet harvesting needs. Nearly all attempted to address the problem of laborious picking. Individuals rigged up suction pickers that worked like vacuum cleaners, motorized pickers, homemade weed whackers, and hand scoops for pulling cranberries out of the water during wet harvesting. Standardized water reels and dry-pickers are now commercially available and greatly increase efficiency.
The raw material needs are modest. The grower requires vines, which often flourish without abating for over 75 years (many are a century old). The land must be peat-rich, sandy, and acidic The beds must be situated near water that can be used to flood the cranberry marshes. No additives are mixed with fresh cranberries prior to packaging.
Preparing the cranberry beds
1 Cranberrry cultivation begins with the preparation of individual
cranberry beds. Cranberries are not planted in bogs or grown underwater.
Cranberries are grown on dry land that is flooded at various points
during cultivation generally for ease of harvesting (and sometimes to
protect the crop from
- 2 Cranberries are grown on vines. New plantings are developed from vine cuttings taken from well-established beds. In the spring cuttings are spread over the prepared soil bed and embedded into the dirt with a dull planting disk. By the end of summer, the vines have rooted. It takes three to five years for these cuttings to begin producing quantities of fruit for commercial processing, but once established, they will produce high-quality fruit for decades.
Caring for the crop
- 3 The cranberry vine begins to bloom in early June. Cranberry vines blossom and flowers begin to open around mid-June. By the end of the month, all of the flowers are in full bloom. The vines must be pollinated by honeybees so they reach their full productivity. In order to ensure pollination, growers bring in about one to two beehives per acre. The result is a concentration of approximately nine million bees in a 100 acre conglomeration of beds. The honeybees continue to pollinate the flowers until early July, when blooming is complete.
4 Small berries appear in July and grow larger until they are harvested
in October. During the growing season the vines, are irrigated and
fertilized. Pest and weed populations are controlled in order to
maximize fruit production.
It is critical to protect the cranberry vines from frost. Temperature alarm systems are installed to alert the growers to low temperatures. When frost is impending, the irrigation system shoots sprays of water over the plants. Heat is released from the water before it freezes thus protecting the plants from damage.
Dry harvesting is the best method for obtaining a firm, fresh bagged cranberry.
- 5 In dry harvesting, cranberry growers use a mechanical picker that resembles a reel lawn mower. Cranberry cultivators train the vines so that the fruit all lies in one direction, allowing the picker's metal teeth to comb the berries off the vine. Berries are placed onto a bucket conveyor that carries them to a burlap sack in the back of the machine. When the sack is full it is lifted off the conveyor and another is put in its place.
- 6 The sacks are emptied onto metal screens that are used to separate the berries from leaves and debris. Next, the berries are crated. When the crates are stacked three high, they are bundled together with a nylon belt. Many cranberry growers use helicopters to airlift crates to nearby flatbed trucks. Since harvesting occurs in the field, the use of helicopters eliminates the potential crushing of the cranberry vines.
- 7 Dry berries are taken to the plant to be sorted. Machines sort out unsuitable berries by bouncing them over a 1 in (2.54 cm) high "bounce board." Firm, round berries bounce over the board, while rotten or bruised berries remain trapped and are discarded. Berries that clear the bounce boards are carried away by conveyor belts and are packaged by machines that check weight and package accordingly.
Wet harvesting is used when the final product will be juices, jams, and jellied sauces.
- 8 Wet harvesting is a quicker processing method than dry harvesting. Ninety-five percent of a crop can be wet harvested in 60% of the time it takes to dry harvest. However, since wet harvested berries are more perishable than dry harvested berries, they are only used for processed cranberry foods. Flooding occurs the night before harvesting is to begin. The beds are flooded with 18 in (45.72 cm) of water. The next day, a machine called a water reel (nicknamed egg beaters) is driven through the water, its paddles churning up the water. The ripe cranberries are agitated just enough to separated from the vine and float to the surface of the water. The floating berries are corralled together with an inflatable boom. A large pipe is placed just beneath the surface of the water in the center of the aggregation of gathered, floating cranberries. The pipe sucks up the berries (along with impurities in the water such as leaves, water, twigs) into a metal box called a hopper.
- 9 The hopper separates the debris from the berries, pumps the water back into the bog, and pumps the berries into a trail truck. The loading of cleaned berries continues until thousands of pounds of berries are loaded into the truck and taken to the plant for processed cranberry foods.
- 10 From late December through March, the cranberry beds are flooded with water until they are completely frozen. The ice forms a protective layer around the plants, protecting them from dehydration and the weather. The plants remain dormant until the following spring.
- 11 Every four years, a layer of sand is added to the top of the frozen beds. As the ice begins to melt, the sand falls to the ground, creating a more established root system and promoting growth.
- 12 The beds are also periodically mowed to encourage shrub health and growth. Mowing occurs in spring and the plants do not produce fruit the year of a mowing.
Quality control of agricultural products such as cranberries includes a wide variety of activities not always associated with what we might generally consider quality control. However, first and foremost, it is important to propagate new vines from old vines that have produced luscious, full, large berries. Second, the vines must be planted in soil that is truly sandy and full of rich peat to ensure necessary nutrients are provided. Then, the beds must be carefully constructed so that the earthworks and dikes adequately control the water flooding. Also, frost warning equipment which alerts that grower as temperatures drop dangerously low must be heeded and sprinkling equipment put into action or the entire crop is at risk.
As with other crops, pests are always a factor in quality control. The grower must be vigilant about checking for pests such as cranberry tipworm or cranberry fruitworm that can ruin a crop if left unchecked (the fruitworm sucks out the meaty centers of berries, fills it full of its excrement and then encases the plants or vines in its silky web). Ultraviolet light traps can be used to attract the fruitworm and then spray the concentration of bugs with a USDA approved insecticide. In fact, insecticides are used for many different bugs but the industry tries to keep their use to a minimum. Fruit fungi and diseases are also issues for cultivators. The industry uses chemicals and carefully monitors weeds, over fertilization, and handling in order to reduce these diseases.
Finally, the machinery used in the processing of cranberries is constructed so as not to bruise or damage the berries. While these are fairly firm berries, they can be bruised if overhandled.
While some cranberry growers do not use pesticides on their crops most do use chemicals to keep pests away from the berries. The United States Department of Agriculture (USDA) maintains strict controls on acceptable pesticides that may be used on fresh fruit and the growers must heed these guidelines. Washing and cleaning the fruit minimizes chemical residue remaining on the harvested fruit. Because the cranberry is harvested in or near water and some of the chemicals specifically formulated to fight diseases and berry blight are moderately toxic to fish, the cultivators must carefully monitor the effects of chemicals on the local fish population.
Cranberry products are very popular and supply never has been equal to the demand. Since there are only 1,200 growers in North America and appropriate land available for cranberry crops is limited because of environmental factors such as wetland protection and limited water access, supply will not grow significantly. Presently, 90% of cranberry consumption occurs in North America. That demand will keep pricing competitive.
Cranberry juice has been an effective home treatment for urinary tract infections for some time and new studies suggest that cranberries are rich in cancer-fighting antioxidants.
Where to Learn More
Jaspersohn, William. Cranberries. Boston: HoughtonMifflin,1991.
"Berry Good for You." The University of California, Berkeley Wellness Letter (February 1999): 2.
Mottau, Gary. "Water Berries." Horticulture (October 1984): 34.
Cranberries in New Jersey. http:/www.burlco.lib.nu.us/ .
Cranberry cultivation in Massachusetts. http://omega.cc.umb.edu/~conne/marsha/ccintro.html .
Maine Cranberry Growers. http://www.nemaine.com/ .
Ocean Spray. http://www.oceanspray.com/ .
Oregon State University. http://osu.orst.edu/ .
Wisconsin State Cranberry Growers Association. http://wiscran.org/ .
— Nancy EV Bryk