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Copyright ©2007 Regents of the University of Minnesota. All rights reserved Currants and gooseberries are closely related berry-producing shrubs well suited to home gardens throughout most of the Upper Midwest. Hardy and productive, they provide fruit for fresh eating, jams, desserts and beverages. Red and white currants are the same species, Ribes sativum. The European black currant is Ribes nigrum. Gooseberries of American origin are Ribes hirtellum or hybrids derived from this species, while the European species is Ribes uva-crispa. Gooseberries and currants, although closely related, can easily be distinguished by examining the canes and fruit; gooseberry canes normally produce a spine at each leaf node and bear roughly grape-sized berries singly or in groups of 2 or 3, while currant canes lack spines or prickles and bear 8 to 30 smaller fruit in clusters (figure 1). A mature gooseberry or currant shrub can produce up to four quarts of fruit annually.
European-type gooseberries, although recognized as larger and better flavored than American types, have not been widely grown in the Upper Midwest due to severe mildew susceptibility, but some European hybrids with mildew resistance have recently become available. Black currants have a strong and unusual flavor, and are widely grown in northern Europe because of their high vitamin C content. They have not been popular in the United States, primarily due to their extreme susceptibility to white pine blister rust. Cronartium ribicola, a serious disease of white pine. Blister rust is little more than a nuisance to the grower of currants and gooseberries. However, it can kill a tree.Although white pine blister rust also can be a problem with commercially available cultivars of red or white currants and gooseberries, rust resistance in such cultivars has generally been greater than with most black currants or wild stands of native Ribes species. But new cultivars of black currant include some with good rust resistance, so home gardeners may now try acquiring a taste for this fruit. In recent years, emphasis in forestry has turned to cultural practices to protect stands of white pine from this disease, rather than prohibitions on planting of Ribes species. The federal restrictions on planting were lifted in 1966. Some states still have retrictions on the planting of Ribes species on the books, but do not enforce these laws. Those that do enforce, do so at the nursery level. Home gardeners and commercial fruit growers in much of the country (including Minnesota) may plant any Ribes they choose. At the same time, new cultivars with improved blister rust resistance have been introduced. Nevertheless, before planting any gooseberry or currant near white pines, you should contact your county extension office or a Department of Natural Resources Regional Forest Health Specialist for up-to-date recommendations. Most commercially available currant and gooseberry cultivars should have adequate winter hardiness for our region. However, very few cultivars have been fully evaluated in outdoor trials by researchers in Minnesota. New cultivars are introduced from European and North American breeding programs every year, so currants and gooseberries should be planted with a sense of adventure. You may be the first person in your county or even in the state to plant the cultivars you choose. Some will work out better than others. Current Currant ResearchAlthough Minnesota is not a center of current research on Ribes production, Cornell University in New York and the University of Idaho have programs that include cultivar evaluation, cultural practices for home and commercial growers, and pest control. Visit these websites for more in-depth information: http://www.fruit.cornell.edu/Berries/specialtyfruit.html http://www.ag.uidaho.edu/sandpoint/Currants%20and%20gooseberries%20guide.htm Red Currant CultivarsJonkheer Van Tets Minnesota No. 71 Perfection Red Lake Red Start Rovada Viking Wilder Pink and White Currant CultivarsThese are albino selections of red currant, generally less acidic and better suited to fresh eating. Blanka Pink Champagne Primus White Imperial Black Currant CultivarsBen Lomond Ben Sarek Consort Crandall Crusader Titania Gooseberry CultivarsCaptivator Colossal Hinnomaki Yellow Hinnomaki Red Invicta Pixwell Poorman Welcome Black Currant-GooseberryJostaberry Site RequirementsCurrants and gooseberries are highly tolerant of less-than-perfect sites. Although full sun will result in the healthiest, most productive planting, the shrubs can perform quite well on as little as half-day sun. A soil pH of 5.5 to 7 (moderately acidic to neutral) is optimal, but growth is fine in alkaline soils as well. Because named cultivars have root systems that are fibrous and shallow, they do not tolerate dry sites without supplemental water. Keep in mind that trees not only cast shade, but compete for water and nutrients as well; a planting location beyond the canopy of shade trees is preferable. Because currants and gooseberries bloom very early in spring, their flowers are susceptible to late-season freezes; temperatures below approximately 28° F can cause damage that will significantly decrease yield. Therefore, a site that warms up more slowly in spring is preferable to a quick-warming location that encourages the plant to get off to too early a start. North-facing slopes and sites that experience winter shade would both work well. If possible, prepare your planting site the fall before you actually plant. Because currants and gooseberries do not perform well under dry or waterlogged conditions, most soils will benefit from the addition of organic material such as shredded peat or compost before planting. Rid the proposed planting site of all perennial weeds as they are much more difficult to control after planting. Test your soil for pH and nutrient needs; professional soil testing may be done through your county extension office. PlantingPlants ordered from mail-order sources are usually sent bare-root, while those purchased from a local nursery may either be bare-root or potted. Because you want your new shrubs to become established before the onset of hot weather, set out either bare-root or potted plants in spring as soon as the soil can be worked; do not be afraid to plant early in the season, as even a plant that is beginning to leaf out can tolerate temperatures as cold as 19° F. When handling bare-root plants, make certain to keep the plants cool and moist until they go into the ground; the delicate root systems must not be allowed to dry or become waterlogged. Just before planting, soak the roots of bare-root plants in a bucket of clean water for three to four hours. Currants and gooseberries should be planted at least an inch deeper than they were in the nursery, in holes deeper and wider than their root systems. If lower canes are covered with soil to a depth of two to three buds, this will encourage a larger root system and the development of numerous renewal canes, a strategy that will maximize the useful lifespan of the plant. Plants may be spaced as close as three feet apart for a hedge-type system in rows at least six feet apart. Black currants are more vigorous and should be spaced four to five feet apart in rows at least eight feet apart. Generally, currants and gooseberries are self-fertile, but research suggests that planting more than one cultivar results in better yields. After planting, prune all canes back to four to six above-ground buds; the resulting low bud count encourages the development of vigorous new canes. At planting time you should also provide two to four inches of an organic mulch such as wood chips, pine needles, or compost. Mulching cools the soil, conserves water, and suppresses weeds, actions that are preferable in a partially shaded site and essential in a sunny spot. Beginning the year after planting, renew mulch annually. If you use a low-nitrogen mulch such as wood chips or sawdust, you may need to apply extra nitrogen at fertilization. Signs of nitrogen deficiency include yellowing leaves (older leaves yellow first) and poor growth. Care and PruningFertilize currants and gooseberries in early spring, before growth begins. Depending on the vigor of last year’s growth, apply ¼ to ½ pound of a balanced fertilizer (the ratio of nitrogen: phosphorus: potassium is indicated by the numbers on the bag; look for three numbers that are the same or close to it, such as 10–10–10) per bush. Apply fertilizer in a band around each bush, working it lightly into the soil from near the canes to a foot or so beyond the branch tips. A composted material rich in nitrogen, such as manure, also makes an excellent fertilizer and may be substituted for a balanced synthetic fertilizer. Because composted materials release their nutrients more slowly than synthetic fertilizers, apply such materials in late fall. You should prune established currant and gooseberry shrubs to encourage vigor and fruit production, improve sun penetration into the bush, and maintain good air circulation to minimize disease. During the first three years of growth, allow four or five canes to develop per year, removing only weak or damaged wood. Beginning in the fourth year, prune out the oldest wood annually in early spring before growth begins. In addition, remove any weak new growth. A mature bush should have 9 to 12 canes once pruning is completed. Fruit is produced on one, two, and three year-old wood. Plants that are particularly vigorous, or that develop a spreading or sprawling habit, will benefit from a simple support system such as that used for raspberries, or from a system of permanent “cordons”, or trunks, such as that used for grapes. HarvestingThere is no simpler way to tell when currants and gooseberries are ripe than to monitor the color and flavor of the fruits as they develop. When using the fruit for jam, you should harvest it before it is fully ripe so that natural fruit pectin levels will be higher. Cool picked fruit quickly, placing it in covered containers or closed bags to maintain humidity levels and prevent drying when storing fruit in a frost-free refrigerator. Promptly cooled berries will keep in the refrigerator for up to several weeks. Diseases and InsectsCurrants and gooseberries do not require extensive spraying to control pests in the Upper Midwest; careful site selection and good cultural practices such as mulching, pruning, and sanitation will minimize pest problems. Powdery mildew can be a serious foliar disease in some years and some locations; it’s a good idea to choose cultivars with mildew resistance. For control of powder mildew or another specific insect or disease pest, contact your county extension office.
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