From: Ronald W. Brooks 
           Subject: [GardenTraders] fruit facts - currants 
           Date: Thu, 28 Oct 1999 17:47:31 -0700 


      From: "Ronald W. Brooks" <orchid@kellnet.com>

      CURRANTS

      Ribes spp.
      Saxifragaceae
      Common Names: Currant (English), Johannisbeere (German), Ribes (Danish,
      Swedish, Italian), Groseille (French), Bes (Flemish).
      The English word 'currant' has been used for this fruit only since 1550,
      taken from the fruit's resemblance to the dried currants of Greece, raisins
      made from a small seedless grape. The much older English name 'ribes' is of
      ancient Indo-European origin and is common to other languages.

      Species: Red, pink and white currants belong to three European species
      (Ribes rubrum, R. petraeum, R. sativum). Black currants are related to
      European (R. nigrum) and Asian (R. ussuriense) species.

      Related Species: Gooseberry (Ribes grossularia, R. hirtellum), Buffalo
      Currant (R. aureum), Jostaberry (R. nigrum X hirtellum).

      Adaptation: Currants grow best in summer humid, cool regions with great
      winter chilling. They are best adapted to USDA Hardiness Zones 3 through 5,
      although in California they are fairly productive in the coolest parts of
      the San Francisco Bay Area and coastal northern California. They should be
      considered experimental only in southern California. Currants are amendable
      to container culture.

      DESCRIPTION
      Growth Habit: All forms of currant are deciduous shrubs, fast growing under
      optimum conditions. The plant is a multiple-stemmed clump, to 5 feet high
      and as broad, but is suitable for training as a standard. Annual growth is
      in a single flush in spring. The roots are superficial, fine and easily
      damaged by frequent cultivation.
      Foliage: The leaves are alternate, single, lobed and maple-like. Black
      currant leaves are pale green, while those of the red currant are deep
      blue-green. Both are easily burned by intense sunlight. Leaf size and number
      is reduced under water stress.

      Flowers: Currant flowers are borne toward the bases of one-year old stems
      and on spurs on older stems. They appear in early spring with new growth.
      Each flower bud opens to number of flowers (up to 20), joined together on a
      delicate, drooping 5 - 6 inch stem, called a strig. The strig length is
      reduced or flowering is suppressed by lack of winter chill. Individual
      flowers (green in the case of red currants and blush pink for black
      currants) are not showy, but joined together on the strig they give the bush
      a lacy texture. Pollination is by hoverflies and other insects. Black
      currant flowers also attract honeybees. Most currants have self-fertile
      flowers, but a few cultivars are partially self-sterile, so set more fruits
      with cross-pollination. To increase both fruit size and number, clip off
      part of the ends of the strigs while the bushes are flowering. Depending
      upon the cultivar, fruits ripen from 70 to 100 days after blossoming.

      Fruit: Fully set strigs will be a pendulous chain of small berries. The
      fruit is easier to pick if their strigs are long and have "handles" (clear
      lengths at the bases) for holding onto while harvesting. Black currants
      commonly ripen from the top down, encouraging birds to strip berries as they
      color. Modern red currant varieties have been selected for their ability to
      ripen all the berries on a strig at once. Berries of red, white and pink
      currants are translucent; black currants are matte brown-purple. The berries
      contain 3 - 12 minute, bony seeds.

      CULTURE
      Location: Currants like morning sun, afternoon part-shade and buoyant air
      circulation. They can be grown in the high shade of fruit trees such as
      persimmon, as well as on the north side of buildings. The leaves sunburn
      readily and the plants collapse quickly when the soil or air temperature
      exceeds 85° F. Currants can withstand ocean winds but the salt air will burn
      the leaves and turn them ragged.
      Soil: Currants are not finicky about soil but, in keeping with their
      proclivity for cold, prefer heavier soils richer in clay. A thick mulch of
      some organic material also keeps the soil cool in summer while adding humus
      to the soil. Sandy soils are less suitable for currants because they dry out
      too fast. The plants will not tolerate alkaline or salty soil.

      Irrigation: With their fibrous, shallow roots, currants are are ideal for
      drip irrigation. Keep the plants watered until the fruit is harvested. At
      this point they stop active growth and the watering frequency can be
      reduced. Plants stressed for water are susceptible to mildew.

      Fertilization: Apply nitrogen at an annual rate of about four ounces per
      square yard. With too much nitrogen the plants become more prone to disease.
      Potassium deficiency, evidenced by marginal scorching of the leaves is
      averted with about half an once of potassium to the square yard. Avoid
      potassium chloride, because currants are sensitive to the chloride ion.

      Pruning: Annual pruning increases yields and keeps plants manageable. Prune
      so that most fruits are borne on spurs of two- or three-year old wood. A
      program of pruning will maintain a continuous supply of such wood. In the
      winter of the plant's first season, remove at ground level all but two or
      three stems. The following winter again remove all but two or three 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. Each winter also shorten long stems that have grown too scraggly.
      Do not prune after spring growth has commenced. Plants can be trained to a
      number of utilitarian and decorative forms.

      Propagation: Currant seeds germinate if stratified for three to four months
      at temperatures just above freezing. Seedlings are prolific and do not vary
      much from parent. Bushes grown from seed bear when two or three years old.

      Currants are easily propagated by hardwood cuttings of one-year old wood.
      Take one-foot cuttings of dormant wood in late winter, dip the base in
      rooting hormone and pot in ordinary soil. Cuttings will quickly root and are
      best kept in part shade for the first year. If the plants are to be grown as
      standards, strip all buds off cutting below soil line. Currants can also be
      grafted, but no advantage is gained.

      Pests and Diseases: Currants are subject to a variety of insect and disease
      pests. Gall mite (not reported yet in California) infests dormant buds
      during summer. Affected buds swell, form dried rosettes, and fail to break
      during following spring. Whole stem becomes blind and dies back to ground.
      Plant should be removed and burned immediately upon detection. Aphids
      commonly distort currant foliage causing red spots. Spider mites are common
      and also cause foliar distortion. Clear-winged borers lay their eggs on
      stems in late spring. The larvae hatch and bore into the stems where they
      remain until the following season. An infestation is usually detected only
      after the stem wilts and dies. Borers will spread and generally cause loss
      of whole a planting without quick control. Cut out affected stems, search
      for others and spray. The leaves are not attractive to deer.

      The most feared disease in black (rarely red) currant is reversion virus,
      and appears as weakened, barren plants with pleated leaves. The virus, which
      is spread by common and gall mites, is endemic in Europe but not yet known
      in California. There is no cure; do not import plant material from European
      sources. Ribes species are also host for white pine blister rust, which
      causes few problems for currants but is lethal for 5-needle pines, including
      California natives such as Western White (Pinus monticola) and Sugar Pine
      (P. lambertiana). Currants are banned in counties where these pines are
      grown for lumber.

      Botrytis and Anthracnose can cause rot of leaves and loss of young growth,
      usually stems lying on the ground or splashed during irrigation. Gooseberry
      mildew infects currants, especially in humid areas, but is not common in
      California. It is worst in coastal fog or where irrigation is by overhead
      sprinkling. Keep plants turgid, never water-stressed. Benomyl spray before
      flowering and after harvest should control it. Currant roots are susceptible
      to both Oak Root fungus (Armillaria) and Phytophthora.

      Harvest: Most cultivars hold well on the plant. For fresh eating let the
      berries hang for about three weeks after they color up. 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. Yields
      vary greatly, depending on growing conditions and cultivar. Anywhere from
      three pounds to over ten pounds may be harvested from a single bush.

      Currants are unsurpassed for jelly, but are also good in pies and sauces,
      especially when mixed with fruits that have body but lack sprightliness.
      Currants have also been used for wine, said by some to be similar in flavor
      to Graves or Rhine wines. Black currants are the traditional source of the
      French liqueur, Cassis.

      CULTIVARS
      Red Currants
      Red currants are for culinary use: juice, jellies and purees. Cultivars are
      selected for the clarity of juice, size of berry and productivity.

      Jonkheer van Tets
      Origin J. Maarse, Schellenkhout (NL), 1931. Seedling of Fay's Prolific.
      Vigorous, habit spreading, bush open. Blooms early, resists mildew. Fruits
      earliest to ripen, tend to run off (drop) from strig.
      Perfection
      Origin Charles Hooker, Rochester NY, 1887. Bush upright, twiggy, roots
      particularly susceptible to Armillaria. Strigs clustered at base of current
      year's growth, fruits small to average, clear red, midseason.
      Red Lake
      Origin W.H. Alderman, Excelsior MN, 1933. Bush vigorous, much branching,
      roots most resistant to Armillaria, tolerates some dryness. Resists mildew.
      Tends to break dormancy early, with protracted bloom, some strigs ripening
      as others are still in bloom. Earlier fruits will mature while soil remains
      moist from winter rains. Berries dark red, rather small.
      Wilder - R. Vulgare.
      Origin E.G. Teas, Irvington IN, 1878. Seedling of Red Versailles. Bush
      spreading, tends to layer self. Largest of red currants. Ripens late, hold
      long on bush. Very productive of full strigs of rather oblate, pale red
      berries.
      White Currants
      An albino forms of the red currant. More versatile but less colorful than
      the red; fine for all culinary uses, but are of lower acidity, thus also
      suitable for fresh eating. The best sorts are nearly transparent.

      Weisse aus Juterbog - R. petraeum.
      Origin Juterbog (D), 1890s. Bush slow growing, upright, sunburns easily. Not
      productive, few berries on short strigs, not adapted to California.
      White Imperial - R. rubrum.
      Origin S.D. Willard, Geneva, NY, 1890. Bush spreading, not upright,
      withstands California conditions well. Very productive on long strigs of
      small round berries. Lowest in acid of currants, suitable for dessert.
      White Versailles - R. vulgare.
      Origin Bertin, Versailles (F), 1840. Bush tall, branches few. Not vigorous.
      Fairly productive of well-filled strigs. Berries round, seedy. Midseason.
      Pink Currants
      Pink Currants are intermediate between red and white types, in degree of
      pigmentation. Skin is colorless, flesh is pink. All are R. vulgare.

      Gloire des Sablons
      Origin France, ancient. Most common form of pink currant. Bush upright, not
      branching, productive, berries quite large but few on strig.
      Black Currants
      Black Currants have a characteristic aroma, highly esteemed by natives of
      northern Europe. Leaves also release the scent when rubbed. Fruit are
      astringent, suitable only for culinary uses. Certain Canadian cultivars
      (Consort, Crusader, Coronet) are R. nigrum X ussuriense hybrids, bred to
      resist mildew and rust, are self- and inter-sterile and of inferior flavor,
      are not recommended.

      Blacksmith
      Origin Laxton Bros, Bedford (GB), 1916. Bush very vigorous, quick to reach
      bearing size, much branching. Productive, strigs long, flavor fair.
      Boskoop Giant
      Origin Boskoop (NL), 1890s. Bush vigorous, upright, branching low. Requires
      pollinator. Strigs few and short, berries not uniform in size. Flavor good.
      Noir de Bourgogne
      Origin Dijon (F), very ancient. The traditional black currant for making
      Cassis. Bush very spreading, low open. Fairly productive, slow to begin
      producing. Strigs short, many, berries of best flavor.
      Wellington XXX
      Origin R. Wellington, East Malling (GB), 1913. Bush spreading, often
      trailing and self-layering. Withstands adverse conditions (sun). Berries
      tend to "run off", shed before strig fully mature. Flavor fair.
      Willoughby
      Origin Walter Willoughby, Parkside, Sask., 1940. Bush open, spreading, hardy
      to cold and sun, resists mildew. Fertile, short strigs, fair flavor.
      Buffalo Currants
      Ribes aureum. A distant relative of the common Ribes, Buffalo Currant is
      probably closer to gooseberry. Native to American prairies, they are
      extraordinarily hardy bushes and productive. The bush resembles common
      Ribes, but is wider and weeping, with branch tips eventually touching the
      ground. It needs no pruning and stems tend to go blind, shedding dormant
      buds after the first year. It tolerates a wide range of soils, even alkali,
      and does not require much winter chill. Leaves are small, felty, gray-green
      and many-lobed. Flowers are profuse, showy, yellow and fragrant, resemble
      Forsythia in bloom. It makes a prolific production of pea-sized or larger,
      glossy brownish-purple, bland-flavored berries with persistent style, that
      resemble American gooseberry when cooked. They are palatable raw or cooked.
      Ripe fruits last long on the bush, often 2 months. It is adaptable to a
      range of climates and the only species recommended for southern California.

      Crandall
      Origin uncertain, probably Iowa, 1890s. Still the best for fruit quality.
      Bush rather weak, weeping, fruit hidden inside foliage, difficult to find.
      Jostaberry
      Jostaberries are hybrids of black currant and the American gooseberry, R.
      hirtellum, produced in Germany, 1930s-50s. They are currently a subject of
      commercial promotion, but performance in California is disappointing. The
      bush is very tall, thornless, tends not to branch and requires the space of
      2 currant bushes. The foliage is glossy, larger than gooseberry, lobed,
      scentless and resists mildew. It survives full sunlight but requires much
      winter chilling. The lateral buds usually shed, leaving blind branches.
      Purple or brownish-red fruit are borne on lax, few-berried strigs. They are
      the size of small gooseberry and lacking in flavor, suitable only for
      experimentation. Buffalo currant produces comparable fruit more abundantly
      in less space and is recommended instead. New forms of Josta, backcrossed to
      the black currant parent, may be better than original types.


      FURTHER READING
      Card, F.W. Bush Fruits. New York, Macmillan, 1907
      Oldham, C.H. The Cultivation of Berried Fruits. London, Crosby Lockwood &
      Son, 1946
      The International Ribes Association, The Ribes Reporter, Vols. 1 - present.
      Reich, Lee. Uncommon Fruits Worthy of Attention. Reading, Mass.,
      Addison-Wesley, 1991. pp 101-112, 1261-171.
      Roe, E.P. Success With Small Fruits. New York, Collier, 1920

      Ron
      The One Who Walks Two Paths
      ICQ 44271371
