Danny L. Barney, Ph.D.

The following information gives a brief overview of currant and gooseberry production. Where more detail is needed, particularly for commercial production, we refer you to Currants, Gooseberries, and Jostaberries: A Guide for Growers, Marketers, and Researchers in North America by Danny L. Barney, Ph.D. and Kim E. Hummer, Ph.D. For more information and to order.

Another good source of information is Currant Genetic Resources.

Currants and gooseberries are members of the genus Ribes and were once grown commercially on more than 7,000 acres in the United States . Their culture, particularly black currants, has largely been restricted in the U.S. because they serve as alternate hosts of the fungal disease white pine blister rust, which has caused major problems for the lumber in­dustry and threatens native stands of five-needled pines. At one time, efforts were even made to eradi­cate all wild and domestic gooseberries and currants. Although eradica­tion efforts failed, the development of new clones of blister rust resistant white pine have reduced the problems associated with the disease, and restrictions on Ribes cultivation are being relaxed.

In a recent survey, Idaho , Oregon , Montana , Wyoming , Utah , and California listed no restrictions on growing or importing currants, other than regulations that apply to all imports of nursery stock. Washington State restricts shipments of fresh currant fruits into some regions to control the plum curculio insect. Because government regulations and laws are subject to change, check with your state department of agriculture before importing or growing currants or gooseberries.

Currants and gooseberries have been collected from the wild for centuries, and were first domesticated in Europe between the 1500s and 1700s. Originally, the fruit was used primarily for herbal medicines. Black currants, for example, are very rich in vitamin C, anthocyanins, phenolics, and have high antioxidant capacity. Today currants are used primarily for juices and syrups, although red currants make exceptional jellies. Gooseberries are used primarily for pastries but make an excellent fresh fruit if allowed to fully ripen. Currant and gooseberry fruits are attractive, and ripe berries hang on the bushes for up to several weeks without overripening.

Site Requirements and Crop Management  

Ribes are quite tolerant of a wide range of soils and can tolerate heavier-textured soils better than many other small fruit crops. While they will survive heavier soils, these crops grow and produce best on deep, well-drained soils. They are not overly sensitive to drought, but irrigation is usually recommended for commercial production in most parts of the northwestern United States . Although experts once recommended the addition of large amounts of organic material to the soil (up to 40 pounds of well rotted manure or compost per 100 square feet), currants and gooseberries will often produce acceptably without such soil amendment.

Best fruit production generally requires a full sun exposure, but currants and gooseberries are susceptible to fruit sunscald at high temperatures (90⁰F an above) and high light intensity. In hot locations, currants and gooseberries can be grown in partial shade.

Currants and gooseberries are heavy feeders. General characteristics and requirements are given in Table 1. Fertilizer recommendations appear in Table 2.

A serious problem in growing currants and gooseberries in North America is powdery mildew. Cultivars differ tremendously in their susceptibility to the disease, so careful cultivar selection is the most effective way to combat the disease. In general, European gooseberries are the most susceptible Ribes crop, followed by black currants and red and white currants. Dormant applications of lime sulfur and/or Bordeaux fungicides help control the disease, as does good sanitation in raking up and disposing of leaves and prunings.

Several other diseases and pests can create problems for currant and gooseberry growers in the Northwest. For help in identifying your crop's problems, the following on-line guides are available to you. Please note that the pesticide recommendations in these guides apply to Idaho , Oregon , and Washington only. For other states, ensure the pesticides are registered for your crop and location. Always read and follow pesticide label directions carefully.

• Currant and Gooseberry Pests and Diseases

• An Online Guide to Plant Disease Control

• PNW Insect Management Handbook

• PNW Weed Management Handbook

 Pruning

Except for cordon-trained plants, most Ribes are pruned while they are dormant during the late winter and early spring, but you can prune any time after the leaves have dropped in the fall. Fall pruning improves air circulation around bushes during wet months and decreases disease problems. Remove unwanted canes as close to the ground as possible and always remove drooping canes that lie close to the ground.

Unless they are damaged or diseased, do not shorten or head back canes. When you must do so, cut immediately above a side branch or strong bud. Be careful while pruning red currants, white currants, and gooseberries not to damage the spurs. Most of the fruit for these crops is borne on short spurs on two and three-year old canes. Black currants bear most of their crop at the base of one-year-old shoots and spurs on two-year-old wood.

Currants and gooseberries are normally trained to bushes, but where space is limited can be trained to trellises or cordons. With mature red and white currant and gooseberry bushes, your goal should be to keep three or four strong, new canes per plant each year, and to remove an equal number of the oldest canes. In this system, mature plants have nine to twelve canes after pruning - three to four each of one-, two-, and three-year-old wood. Remove all wood that is four years old or older.

Black currants are more vigorous than other currants and gooseberries, and you normally leave more canes. As a general rule, leave ten to twelve vigorous canes per bush. If the bushes are very vigorous, leave a few more canes. About half of the canes left after pruning should be one-year-old, with the remaining half being vigorous two-year-old canes that have an abundance of one-year-old shoots. Remove all canes that are more than two years old.

 Harvesting and Using the Fruit

There has long been a misconception that currants and gooseberries must be harvested before they are ripe, or they will not process well.

That misconception has discouraged the use of these fine fruits because green currants and gooseberries are unpalatable, to say the least. In England , gooseberries are harvested before they are fully ripe and used in pastries and desserts. Commercially, this is called the green berry trade. The flavor of both currants and gooseberries is far better if the berries are allowed to ripen on the bushes. Even fully ripe fruit makes excellent preserves when you follow standard canning procedures.

Black currants are the first to ripen, typically around the first of July in northern Idaho and late June or early July in warmer areas. Red and white currants begin ripening about a week or two later and ripen over a two-week period. Some currant cultivars ripen later than others.

Currants may be harvested two or three times, but all of the fruit from a particular cultivar is usually harvested at one time. Wait until all of the berries on the bush are ripe. Berries at the tops of the fruit clusters ripen before those at the tips. Harvest the fruit after it softens and is fully ripe, but before it begins to shrivel. Pick the berries into one-half or one-pint flats. Pick the fruit by pinching off the fruit clusters (called strigs) where they attach to the stem. Particularly with red and white currants, do not strip the berries from the clusters. Black currants are firmer than red and white cultivars, and are sometimes stripped from the bushes.

Unless you plan to use them immediately, do not wash the berries before refrigerating them. Doing so increases fruit rot. Wash the berries just before use. If you are making juice by pressing the berries, you do not have to remove the stems. If you cook the fruit down before straining, crush the berries into a large pot and remove the stems to prevent the development of a grassy flavor during cooking.

Gooseberries ripen two to four weeks after black currants and ripen over a four-week period. For hand-harvested, fresh fruit, the berries are often harvested in three pickings. During the first picking, remove one-third of the ripe or nearly ripe fruit evenly from throughout the bush. A week later, remove half of the remaining ripe fruit, leaving the rest on well exposed spurs on the outside of the bush. Finally, harvest the remainder of the fruit when it is fully ripe. The fruit from the first two pickings is normally used for processing. Fruit from the last picking is usually larger and sweeter, and is good for fresh use or processing. For commercial processing, gooseberries are normally only harvested once. Remove the stems and tails from the gooseberries before cooking.

For large, commercial operations where fruit is destined for processing, currants are now almost exclusively harvested using over-the-row mechanical harvesting machines. Gooseberries are also sometimes harvested mechanically, although the fruits tend to be punctured by thorns during harvest.