Currants, a fruit with a long and interesting history, are attracting a lot of attention of late, providing another example of how "what's old is new again". These small, delicious, and in some cases ornamental berries are borne on bushes belonging to the genus Ribes and are native to northern latitudes of Europe, Asia, and North America. This genus contains about 150 species, grouped into categories including the red and white currants, the black currants, ornamental currants, golden currants, and gooseberries. Within individual species, there are many cultivars that have been developed over the years, making this a truly expansive plant group.
The word 'currant' is derived from the ancient Greek city of Corinth, which was known for its production of small dried grapes known now as Zante Currants. Early references to Ribes currants use words like corinthes, corans, currans, and bastarde corinthes. Known currant culture in farms and gardens dates back at least as far as the Renaissance in Europe, and to the arrival of early colonists in North America in the late 1700's, though native Americans were known to harvest them from the wild. Old herbalist texts from the 1600's describe the medicinal properties of currants. Native Americans used them in medicines and dyes. In 1629, a memorandum of the Massachusetts Company includes currants among a list of plants destined for the "New World Colonies". The botanical roots of this genus go even further back, as the origins of the genus name Ribes trace back from the Syrian or Kurdish ribas, which was derived from an old Persian word riba. Early selection and breeding programs beginning in the 1700's and 1800's and continuing today have led to the multitude of cultivated varieties we now know. In addition, many wild species have also been identified throughout their native regions.
Currants in the New World
Ribes spp. were both native to North America and transported here via early trade ships in the 1600's and 1700's. The Prince Nurseries on Long Island became the first nursery to offer currants for sale in 1770. In the 1800's and into the early 1900's, black and red currants were widely grown in the U.S. and Canada. In 1882, The New York Agricultural Experiment Station was established in Geneva NY, and with it an active breeding program for currants. By 1899, over 12,000 acres of commercial production had been established in the United States, much of it in New York.
The fate of currants in the New World began to change at the turn of the century when in the late 1890's the fungus that causes White Pine Blister Rust (Cronatium ribicola) was imported to the New World on infected pine seedlings. This fungus requires two alternating hosts in order to complete its life cycle: any of several 5-needle pines (including white pine) and any susceptible genotype of Ribes. The most susceptible genotypes are among the black currants.
By 1911, the disease had been reported in most of the Northeast, including Massachusetts. The federal government issued a plant quarantine in 1920's against the importation and cultivation of any Ribes plants. This was followed by an active eradication program by the Civilian Conservation Corps (CCC) during the Great Depression. As many as 11,000 CCC men were employed in a single year for Ribes eradication in the national forests. The CCC Eradication Program went on into the early 1940's and the federal quarantine was rescinded in 1966, leaving it up to individual states whether or not to maintain restrictions.
Massachusetts has retained, to this day, the regulation that was promulgated in the 1920's which prohibits black currants statewide and allows red or white currants and gooseberries only in certain towns. The exact text, including the list of allowed towns, can be found at the Massachusetts Dept. of Agricultural Resources web site at: http://www.mass.gov/eea/docs/agr/legal/regs/330-cmr-6-00.pdf
What's Current About Currants?
Much new research has been done to better understand white pine blister rust (WPBR) and the risk it poses to pines. Environmental and physiographic conditions conducive to the spread of this disease have been defined. New cultivars have been developed that are resistant or immune to WPBR. Also, while little commercial production has persisted since the original heyday of American currant production at the turn of the century, wild Ribes have survived eradication and are commonly found in the forest understory. Despite this, the occurrence of WPBR in much of the Northeast is rare.
Since the time that the federal quarantine against Ribes was lifted, many states have rescinded or modified their Ribes restrictions. Massachusetts still maintains its regulations but is in the process of initiating some changes. New York now allows any WPBR resistant black currant and all red or white currant varieties to be grown statewide and non-resistant varieties in designated areas of the state; commercial production is being re-established. Connecticut and Vermont allow all currants statewide and have sizeable commercial plantings in place. New Hampshire only restricts non-resistant varieties of black currants. Maine continues to prohibit all black currants, while Rhode Island prohibits several species of Ribes and requires permits for other types and for importation of white pine.
Renewed interest in currants by commercial producers and homeowners alike center around their appeal as a specialty crop, new to some consumers and nostalgic to others. Black currants are used in products ranging from tea to wine, jelly to syrup, ice cream to liqueur, even as a popular soft drink called ‘Ribena' sold in vending machines in the UK.
Another source of interest comes from the nutritional composition of this little powerhouse berry. For example, in the USDA Nutrition Handbook, black currants are listed as containing:
- More ascorbic acid (Vitamin C), by far, than any other available fruit
- As much potassium as bananas
- Twice as much calcium as any fruit except blackberry
- Less fat than all other fruit except nectarines
- More phosphorus and potassium than any other fruit
- Second only to elderberry in iron and protein
Black currants also contain bioflavanoids which are vasopressor agents (reduce blood pressure).
Currants also have ornamental appeal. In the home landscape, many options exist for incorporating the ornamental qualities of fruit, flowers and foliage into foundation plantings or gardens. Flower color ranges from white to a deep red and foliage has varying colors and textures too. 'Crandall' is a black currant cultivar that is immune to WPBR, has a profusion of beautiful ornamental yellow flowers, and silvery feathered foliage that turns a brilliant orange in the fall.
Site and Soils
Currants grow best in loamy soils with good drainage (not droughty), a pH of 6.0 to 6.5, and moderate organic matter content. Roots are relatively shallow, extending to 8-16 inches, so deep soils are not needed. But, this exposes them to more drying, so irrigation may be needed during dry spells. Unlike many other fruit crops, currants are somewhat shade tolerant, but will produce more fruit in full sun.
Most commercial varieties of currants are hardy to zone 4, so they are well adapted to our New England climate. However, while they can withstand winter temperatures of more than -20°F, they do not tolerate high summer temperatures very well. Therefore, they should be planted on northerly slopes or protected with shade or even cooling irrigation in sites where temperatures are above 85°F for extended periods during fruiting.
Most varieties are harvested in July in our area. They are often among the first plants to leaf out in the spring and also begin to drop leaves early in the fall.
Plant size is generally similar to blueberry bushes, 5' tall and 3-4' wide with new stalks coming up from the crown. Pruning is very similar to blueberries where wood older than 4-5 years is removed and a balance is maintained of 1-, 2-, and 3-year old wood.