Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus Oxycoccus of the genus Vaccinium. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender stems that are not thickly woody and have small evergreen leaves. The flowers are dark pink. The fruit is a berry that is larger than the leaves of the plant; it is initially light green, turning red when ripe. The raw berry is edible and has a tart taste due to the low sugar content and high acidity.
In Britain, cranberry may refer to the native species Vaccinium oxycoccos, while in North America, it may refer to V. macrocarpon. The former is cultivated in central and northern Europe, while the latter is cultivated throughout the northern United States, Canada, and Chile. In 2020, the U.S., Canada, and Chile accounted for 97% of the world production of cranberries. Most cranberries are processed into products such as juice, sauce, jam, and sweetened dried cranberries, with the remainder sold fresh to consumers. Cranberry sauce is a traditional accompaniment to turkey at Christmas and Thanksgiving dinners in the U.S. and Canada, and at Christmas dinners in the United Kingdom.
Description Cranberries are low, creeping shrubs or vines up to long and in height; they have slender, wiry stems that are not thickly woody and have small evergreen leaves. The flowers are dark pink, with very distinct reflexed petals, leaving the style and stamens fully exposed and pointing forward. They are pollinated by bees. The fruit is a berry that is larger than the leaves of the plant; it is initially light green, turning red when ripe. It has an acidic taste which usually overwhelms its sweetness.
Similar species Cranberries are related to bilberries, blueberries, and huckleberries, all in Vaccinium subgenus Vaccinium. These differ in having bell-shaped flowers, petals that are not reflexed, and woodier stems, forming taller shrubs.
Taxonomy In some methods of classification, Oxycoccus is regarded as a genus in its own right.
Species There are 4–5 species of cranberry, classified by subgenus:
Subgenus Oxycoccus Image Name Description Distribution Vaccinium oxycoccos or Oxycoccus palustris (common cranberry, northern cranberry or cranberry) It has small leaves, with an inrolled margin. The flowers are dark pink, with a purple central spike, produced on finely hairy stalks. The fruit is a small pale pink to red berry, with a refreshing sharp acidic flavor. Widespread throughout the cool temperate Northern Hemisphere, including northern Europe, northern Asia, and northern North America.Vaccinium microcarpum or Oxycoccus microcarpus (small cranberry) It is highly similar to V. oxycoccos, differing in the leaves being more triangular, and the flower stems hairless; additionally, their stems can also be smaller and produce a smaller number of flowers than V. ocycoccos. They also differ in the fact that their leaves can be smaller in size, even though the main difference is their triangular shape. Some botanists include it within V. oxycoccos.Occurs in northern North America, northern Europe and northern Asia.Vaccinium macrocarpon or Oxycoccus macrocarpus (large cranberry, American cranberry, bearberry) It differs from V. oxycoccos in the leaves being larger, long, and flat, and in the slightly apple-like taste of the berries. Native to northern North America across Canada, and eastern United States, south to North Carolina at high altitudes).
Subgenus Oxycoccus, sect. Oxycoccoides Image Name Description DistributionVaccinium erythrocarpum or Oxycarpus erythrocarpus (southern mountain cranberry, bearberry) This species differs significantly from sect. oxycoccus cranberries particularly in growth habit. A deciduous shrub, their flowers are borne in June of a tubular shape with reflexed petals consistent with the rest of the subgenera. They produce edible scarlet berries described as being seemingly translucent. Native to southeastern United States at high altitudes in the southern Appalachian MountainsVaccinium japonicumThey are typically found in forests and thickets within alpine areas between .Native to Southern China, Taiwan, the Japanese archipelago, and the Korean Peninsula
Etymology
The name cranberry derives from the Middle Low German (English translation, craneberry), first named as cranberry in English by the missionary John Eliot in 1647. Around 1694, German and Dutch colonists in New England used the word, cranberry, to represent the expanding flower, stem, calyx, and petals resembling the neck, head, and bill of a crane. The traditional English name for the plant more common in Europe, Vaccinium oxycoccos, fenberry, originated from plants with small red berries found growing in fen (marsh) lands of England. Distribution and habitat Cranberries can be found in acidic bogs throughout the cooler regions of the Northern Hemisphere.
Cultivation
American Revolutionary War veteran Henry Hall first cultivated cranberries in the Cape Cod town of Dennis around 1816. In the 1820s, Hall was shipping cranberries to New York City and Boston from which shipments were also sent to Europe. In 1843, Eli Howes planted his own crop of cranberries on Cape Cod, using the "Howes" variety. In 1847, Cyrus Cahoon planted a crop of "Early Black" variety near Pleasant Lake, Harwich, Massachusetts. By 1900, were under cultivation in the New England region. In 2021, the total output of cranberries harvested in the United States was , with Wisconsin as the largest state producer (59% of total), followed by Massachusetts, New Jersey, and Oregon. Cranberries have had two major breeding events. The first occurred in the 1920s, with aims to create a crop that was more insect-resistant, specifically to blunt-nosed leafhopper (Limotettix vaccinii), the vector of a phytoplasma that causes cranberry false blossom disease. This resulted in cultivars such as "Stevens" and "Franklin". As such, cultivars like "Howes" tend to be more susceptible to insects than "Stevens". However, with the introduction of many broad-spectrum pesticides in the 1940s and 1950s, breeders eventually stopped breeding for pest resistance. Instead, beginning in the 1980s, cranberries were bred for high-yielding varieties, leading to cultivars such as "Crimson Queen" and "Mullica Queen". Many of these varieties were spearheaded and bred by Dr. Nicholi Vorsa of Rutgers University. In more recent years, there have been heavier restrictions on pesticides due to environmental safety concerns, leading to a greater emphasis on high yield, high resistance varieties.
Geography and bog method
Historically, cranberry beds were constructed in wetlands. Today's cranberry beds are constructed in upland areas with a shallow water table. The topsoil is scraped off to form dykes around the bed perimeter. Clean sand is hauled in and spread to a depth of . The surface is laser leveled flat to provide even drainage. Beds are frequently drained with socked tile in addition to the perimeter ditch. In addition to making it possible to hold water, the dykes allow equipment to service the beds without driving on the vines. Irrigation equipment is installed in the bed to provide irrigation for vine growth and for spring and autumn frost protection.
A common misconception about cranberry production is that the beds remain flooded throughout the year. During the growing season cranberry beds are not flooded, but are irrigated regularly to maintain soil moisture. Beds are flooded in the autumn to facilitate harvest and again during the winter to protect against low temperatures. In cold climates like Wisconsin, New England, and eastern Canada, the winter flood typically freezes into ice, while in warmer climates the water remains liquid. When ice forms on the beds, trucks can be driven onto the ice to spread a thin layer of sand to control pests and rejuvenate the vines. Sanding is done every three to five years.
Propagation Cranberry vines are propagated by moving vines from an established bed. The vines are spread on the surface of the sand of the new bed and pushed into the sand with a blunt disk. The vines are watered frequently during the first few weeks until roots form and new shoots grow. Beds are given frequent, light application of nitrogen fertilizer during the first year. The cost of renovating cranberry beds is estimated to be between .
Ripening and harvest
Cranberries are harvested in the fall when the fruit takes on its distinctive deep red color, and most ideally after the first frost. This is usually in September through the first part of November. Berries that receive sun turn a deep red when fully ripe, while those that do not fully mature are a pale pink or white color. To harvest cranberries, the beds are flooded with of water above the vines. A harvester is driven through the beds to remove the fruit from the vines. Since the 1960s, water reel type harvesters have been used. Harvested cranberries float in the water and can be corralled into a corner of the bed and conveyed or pumped from the bed. From the farm, cranberries are taken to receiving stations where they are cleaned, sorted, and stored prior to packaging or processing. While cranberries are harvested when they take on their deep red color, they can also be harvested beforehand when they are still white, which is how white cranberry juice is made. Yields are lower on beds harvested early and the early flooding tends to damage vines, but not severely. Vines can also be trained through dry picking to help avoid damage in subsequent harvests.
Although most cranberries are wet-picked as described above, 5–10% of the US crop is still dry-picked. This entails higher labor costs and lower yield, but dry-picked berries are less bruised and can be sold as fresh fruit instead of having to be immediately frozen or processed. Originally performed with two-handed comb scoops, dry picking is today accomplished by motorized, walk-behind harvesters which must be small enough to traverse beds without damaging the vines.
Cranberries for fresh market are stored in shallow bins or boxes with perforated or slatted bottoms, which deter decay by allowing air to circulate. Because harvest occurs in late autumn, cranberries for fresh markets are frequently stored in thick walled barns without mechanical refrigeration. Temperatures are regulated by opening and closing vents in the barn as needed. Cranberries destined for processing are usually frozen in bulk containers shortly after arriving at a receiving station.
Diseases
Diseases of cranberry include: Cranberry fruit rot Cranberry root rot Cranberry false blossom disease, caused by a phytoplasma that is vectored by the blunt-nosed leafhopper (Limotettix vaccinii), and prevents the plant from creating fertile flowers and thus berries.
Insect pests Probably due to the high phenolics and plant defenses, in addition to the harsh environments that cranberries are grown under (acid, sandy soils that get flooded every year), a majority of insect pests associated with cranberries are native to the cranberry's home range of North America. The top studied insect pests of cranberries include: Sparganothis sulfureana (Sparganothis fruitworm), a leafrolling moth Acrobasis vaccinii (cranberry fruitworm), a snout moth Rhopobota naevana (blackheaded fireworm), a leafrolling moth Choristoneura parallela (spotted fireworm), a leafrolling moth All four of these top studied insect pests are direct pests, eating the berries.
Other well studied cranberry pests include: Limotettix vaccinii (blunt-nosed leafhopper), a leafhopper Lymantria dispar (spongy moth), an invasive moth Dasineura oxycoccana (cranberry tipworm), a gall-forming midge Chrysoteuchia topiarius (cranberry girdler), a snout moth Anthonomus musculus (cranberry weevil), a weevil Systena frontalis (red-headed flea beetle), a flea beetle