Ribes rubrum, Ribes sativum, and Ribes petraeum are members of the Saxifragaceae (saxifrage) family.

Red and white currants are, for all practical purposes, the same fruit, differing only in color. Cultivars are drawn from combinations of primarily three species of Ribes, all deciduous shrubs. The first species is R. rubrum, an upright shrub native from northern Europe across to Siberia and Manchuria. The second species , R. sativum (R.vulgare), is a spreading shrub of the cool, temperate regions of western Europe. The cultivar 'cherry' is a large-fruited form of R.sativum. And the third species is R. petraeum, a native of high mountain areas of north Africa and Europe. This vigorous grower bears the tartest fruit of all three species, and is represented by such cultivars as 'Prince Albert' and 'Goudouin'.

Currant flowers are born towards the bases of one-year-old stems, and on spurs on older stems. Each flower bud opens to a number of flowers, joined together on a delicate, drooping stem, called a "strig." Most currants have self-fertile flowers, but a few cultivars are partially self-sterile.

Use. Currants are unsurpassed for jelly, for which use the fruits should be picked as soon as they turn red. Currants also are good in pies and sauce, especially when mixed with other fruits which have body but lack sprightliness. The crushed fruit makes a refreshing summer -ade.

Currants also have been used for wine. "The wine made from white currants, if rich of fruit, so as to require little sugar, is, when kept to a proper age, of a flavor similar to the Grave and Rhenish wines; and I have known it preferred as a summer table wine," wrote Henry Phillips in his Pomarium Brittanicum (1820).

Certain currant cultivars become delicious for eating out of hand if left hanging on the bush for about three weeks after the berries first turn red. If the fruits are to be stored at all, they should be picked dry. To avoid damaging the fruits, pick a whole strig by its stem, taking care not to damage the spur.

Currants are a popular fruit among northern Europeans. The fruit is little known in America because the plant was blamed for spreading the disease white pine blister rust, so a federal law passed in the 1920s banned the growing of Ribes over much of the country. Red and white currants are, in fact, relatively resistant to the disease. The federal law was lifted in 1966, and there is now renewed interest in America in these fruits.

Climatic practices. A horticulturalist of the past century wrote: "The currant takes the same place among fruits that the mule occupies among draught animals - being modest in its demands as to feed, shelter, and care, yet doing good service."

Currants thrive in cool, well-drained, fertile soils. In warmer regions, bushes will grow better and produce better fruit in heavier soils, which retain more moisture and keep cooler. An organic mulch is beneficial, both to protect the shallow roots and to keep the soil cool and moist. The bush will thrive in full sun or in partial shade. In warmer summer areas, plant the bushes in partial shade or on a north-facing slope.

A currant bush has a moderate need for nitrogen and a high requirement for potassium. The symptom of potassium deficiency is scorching of leaf margins, and deficiency can be avoided with an annual dressing of a half-ounce of actual potassium per square yard. Do not use muriate of potash (potassium chloride) to supply potassium, since currants are sensitive to chloride ion toxicity.

Though currant plants tolerate neglect, annual pruning increases yields and keeps plants manageable and healthy. Prune so that most fruits are borne on spurs of two- and three-year-old wood, even though younger and older wood also bear some fruit.

Most commonly, currants are grown as bushes spaced five feet apart each way. A "renewal" method of pruning maintains a continuous supply of two or three each of one-, two-, and three-year-old stems. The winter of a plant's first season, remove at ground level all but two or three stems. The following winter again remove all but two or three of the stems that grew the previous season, at which point the bush will have two or three each of one- and two-year-old stems. Continue this each season, but by the fourth winter start cutting away at their bases any stems more than three-years-old; some growers remove stems after their second year. Each winter also shorten long stems that have grown too scraggly. Remove low-hanging branches which droop near the ground.

Cordons - plants grown as a single stem - are a tidier way of growing currants, useful where many different cultivars are desired in a small area or where the plants are grown against a wall. You can plant cordons a foot-and-a- half apart or train them against a wall in a bed less than a foot deep.

When developing a cordon, shorten the single upright stem each winter to six inches of new growth, and any laterals to two buds. During the summer, pinch developing laterals (not the leaders) to five leaves just as berries are beginning to color. When the leader reaches its allotted height, shorten it each winter to one bud of the previous season's growth, and prune the laterals each winter and summer as before.

Pest and disease problems. Red and white currants are subject to a few insect and disease pests, though it is possible to grow them with little or no spraying. The plants commonly are attacked by a species of aphid which cause the leaves to blister and redden. The aphid often can be ignored and the cosmetic damage tolerated, otherwise spray the plants with an insecticide, making sure to get the undersides of the leaves.

The currant borer makes its presence known when a stem wilts. This insect lays its eggs on the stems in late spring. The larvae hatch and bore into the stems, where they cause a swelling and remain until the following season. Control this pest by cutting infested stems off six inches below swellings.

Spider mites can be a problem especially under dry, dusty conditions. Drought stressed plants turn yellow and defoliate during the heat of summer. Keep plants cool, moist and ward off mites with overhead water, insecticidal soap, or spray with summer oil.

The imported currantworm, despite its name, is more commonly a pest of gooseberry than of currant. Nonetheless currants can be defoliated by this pest in just a few days. This insect quickly strips the foliage from the plant just as the leaves fully open, then again about the time the fruit is ripening. If control is necessary, spray with an insecticide as soon as damage is noticed.

Two diseases, leaf spot and anthracnose, can cause currants to defoliate in summer. The diseases can be treated together as far a symptoms (spots on leaves) and control. Since both diseases spend the winter on old leaves, cleaning up these leaves in autumn will limit the disease. The plants also can be sprayed with an appropriate fungicide just after their leaves unfurl, then again after harvest.

Under certain conditions and with certain cultivars, powdery mildew may cause sufficient damage to warrant control. Select resistant cultivars and provide good air movement. A fungicide can be used to control the mildew during the spring.

Propagation. Currants are easily propagated by hardwood cuttings of one-year-old wood. If the plants are to be grown in tree form, or on short "legs,: remove all but the top three buds from the cutting so that sprouts do not grow from below ground. currants leaf out early in the spring, so set cuttings in the ground either in the fall or very early in the spring.

(Note: The cultivars such as 'Red Lake', 'Wilder' and 'Minnesota 71' are excellent cultivars, and are widely available. 'Jonkheer van Tets' and 'Cherry' are resistant to powdery mildew. The following nurseries offer more extensive selections of cultivars.)

Alexander Eppler Ltd., P.O. Box 16513, Seattle, WA 98116-0513

International Ribes Association, c/o Anderson Valley Agricultural Institute, P.O. Box 130, Boonville, CA 95415

Southmeadow Fruit Gardens, Lakeside, MI 49116

Whitman Farms Nursery, 1420 Beaumont NW, Salem, OR 97304

Baker, Harry. The Fruit Garden Displayed. Cassell Ltd., The Royal Horticultural Society. 1986.

Darrow, G. and S. Detwiler. Currants and gooseberries: their culture and relation to white-pine blister rust. U.S. Department of Agriculture Farmer's Bulletin No. 1398. 1924.

Reich, Lee. Uncommon Fruits Worthy of Attention: A Gardener's Guide. Addison-Wesley Publishing Co., Reading MA. 1991.

Thayer, P. The red and white currants. Ohio Agriculture Experiment Station Bulletin 371. 1923.

Blackberries, Currants, and Gooseberries. Cooperative Extension Publication No. IB97. Distribution Center C, 7 Research Park. Cornell University, Ithaca, NY 14853.

Galletta, G. and D. Himelrick (eds). Small Fruit Crop Management. Prentice Hall, West Nyack, NY. 1990.

Antonelli, A. et al. Small Fruit Pests - Biology, Diagnosis, and Management. Publication EB 1388, Washington State University Agricultural Communications, Pullman, WA. 1988.

Lee Reich, PhD is a horticultural consultant and writer based in New Paltz, New York. He has been fruit researcher for both Cornell University and for the U.S. Department of Agriculture.

Reviewed by Dan Barney, 12/2/91

Reviewed by Paul Vossen, 12/20/91

1/7/92