Ribes are on the rise.
Currants and gooseberries (of the genus Ribes) have long been grown throughout continental Europe and Britain, where the fruits have traditionally been enjoyed in tasty concoctions like wines, brandies, juices, jams and jellies. These flavourful berries, however, have never been planted extensively in North America. For many years, in fact, Ribes crops were actively discouraged and even prohibited here because some species are alternative hosts to the devastating white pine blister rust causal organism, Cronartium ribicola.
In recent years, however, interest in Ribes has been on the rise, both commercially and in home gardens. Around the world, a growing number of disease-resistant cultivars have been developed, while the distinctive flavours of the fruits have made their way into various brands of juices and preserves. Meanwhile, nutritionists have been touting the fruits' high vitamin C content, boosting their popularity with the health-conscious among us.
Growing Ribes in B.C.
Here in British Columbia, our south coast region offers some of the best conditions in the world for growing Ribes fruits. In fact, most cultivars will flourish throughout much of our province, although high summer temperatures can limit growth and fruiting. Gooseberries, however, are usually more heat tolerant than currants.
Success with Ribes is usually assured in areas with 120 to 140 frost-free days. Use only certified pathogen-free stock, preferably two-year-old plants, to establish new plantings. It is never a good idea to take cuttings from bushes in your neighbour's garden. Plant in late October or early November, or else in late winter, to ensure good root growth before warmer weather can cause moisture stress. Space blackcurrant bushes about 1.5 metres apart. Red and white currant and gooseberry bushes are usually less vigorous and can be planted slightly closer together.
In the home garden, currants and gooseberries are usually grown as free-standing bushes, which develop through the continual renewal of crown shoots. Cut all canes back to two to four buds the first time you prune them. Yearly, allow four or five shoots to develop until 12 to 15 canes comprise the mature bush, and prune during the dormant season.
Currant shoots have short internodes and small leaves whereas gooseberry shoots have longer internodes and larger leaves. Flower buds are located on one-year-old shoots. In blackcurrants, buds are mostly located laterally along the shoots; in redcurrants and gooseberries they are located terminally. Blackcurrants produce mostly on one-year-old wood, while redcurrants and gooseberries produce most of their fruit on shoots of two- and three-year-old wood. Canes older than three years should be removed from all Ribes bushes.
Soil and Nutrients
The plants do best in well-drained, deep, loamy soils containing more than one per cent organic matter, with an optimum pH level between 5.5 and 7. The soil should never be allowed to dry out or become waterlogged. Because of the plants' shallow root system, I recommend mulching to ensure an even moisture supply and help control weeds. You can also control weeds by hand-pulling or by gentle hoeing, being careful not to disturb the roots.
Nutrient requirements for Ribes bushes are not high, and the actual amounts needed depend on your soil type. It is usually best to apply nitrogen in the early spring, while other nutrients can be added in summer or early fall. In general, I would suggest 115 grams of 10-10-10 per mature bush each spring. Applying well-rotted manure and/or compost in spring should also meet most nutrient requirements.
Pests and Diseases
Where possible, control for pests and diseases by selecting resistant Ribes cultivars. The seriousness of problems like powdery mildew and fruit rot can also be alleviated by improving air circulation - by thinning out some of the canes, planting bushes further apart with wider row spacing, or by removing surrounding trees or hedges. Establishing the bushes in the highest area of your garden will also improve air flow. And be sure to keep your plants free of debris, clearing away and burning any leaves or other plant materials that look infected.
To reduce the incidence of powdery mildew, try a spray of washing soda (sodium carbonate) and soft soap, which will also aid in the control of aphids and other insects. If all else fails, use a Bordeaux and lime sulphur spray to control powdery mildew.
The resurgence of interest in currants and gooseberries has led to increased breeding efforts around the world. Scotland has been leading the way in producing improved blackcurrant cultivars, such as 'Ben Lomond,' which produces large fruit and is currently the most widely planted cultivar in Britain. 'Ben Alder,' which produces high yields of small fruits, and 'Ben Tirran,' which has good resistance to powdery mildew, are both late flowering, making them well suited to regions subject to late spring frosts.
Many of the newer blackcurrant cultivars are more disease and pest resistant than traditional standards such as 'Baldwin' and 'Mendip Cross.' The exceptions are three older Canadian cultivars - 'Consort,' 'Cornet' and 'Crusader' - each of which has resistance to white pine blister rust but is low yielding with small fruit. Of the new cultivars, Sweden's 'Titania' produces large yields of big fruit and is also highly resistant to white pine blister rust. Scotland's 'Ben Sarek' and 'Ben Conan' also produce large fruits and show some rust resistance.
Red and White Currants
For many years, winter-hardy 'Viking' and 'Red Lake' have been popular redcurrant cultivars in North America. 'Viking' is higher yielding and shows more resistance to white pine blister rust and to powdery mildew. 'Redstart' is a high-yielding cultivar from England but it is susceptible to powdery mildew. From the Netherlands, 'Rovoda' produces large, relatively late-ripening fruits on bushes resistant to powdery mildew, while the older 'Jonkheer van Teets' produces early-ripening fruit.
White currants are better known in Europe than in North America. In my own garden I have a bush that in most years produces enough fruit for one or two jars of delicious jelly. White cultivars include 'White Dutch,' 'Albatross,' 'Blanka,' 'Primus,' 'White Grape' and 'Pink Champagne,' a pink cultivar with a particularly appealing flavour.
Gooseberries Old and New
Choices in gooseberry cultivars abound, including older ones like 'Whinham's Industry' (dark-red fruit), 'Careless' (pale green-milky white), 'Oregon Champion' (rosy pink), 'Pixwell' (pale green-pink), 'Hinnonmaki Red' (red) and 'Hinnonmaki Yellow' (green-yellow). Of these, 'Oregon Champion' and 'Pixwell' are especially winter hardy. 'Invicta' and 'Pax' are two relatively new English cultivars. 'Invicta' is resistant to powdery mildew and produces high yields of large, pale-green fruit with good fresh eating qualities. 'Pax,' which has virtually spineless bushes, is also high yielding and has some resistance to powdery mildew. It produces flavourful red berries. 'Pax' is now in quarantine in Canada and may be available in the future. 'Jahn's Prairie' is a notable new gooseberry cultivar that produces high yields of large, red-pink, relatively late-ripening fruit. The plant has resistance to a range of diseases and pests, making this definitely one to look for at your garden centre.
You may also spot the odd Jostaberry bush at a garden centre. The Jostaberry is a cross between a blackcurrant and a gooseberry, with cultural requirements similar to the gooseberry. It is spineless, virtually pest and disease free, and extremely vigorous, with acidic-tasting fruits that range from dark red to black. The fruit is high in vitamin C and good for making jams.
Virtually all the Ribes cultivars are bee-pollinated and self-fertile, although blackcurrant fruit set may be improved if more than one cultivar is planted, which will also extend the harvest season and give you even more opportunities to enjoy the fruit. Unlike some berries, ripe currants and gooseberries can remain on their bushes for up to four weeks without becoming overripe. Pick these tiny treats at your leisure, and you may still find plenty of time to prepare a few luscious preserves and gooseberry pies before the end of the season.
Hugh Daubeny is a research scientist emeritus with Agriculture Canada's Pacific Agriculture Research Centre, where he spent 35 years developing strawberry and raspberry breeding programs. For those interested in learning more about Ribes, he recommends reading the book Growing Fruit by Harry Baker of the Royal Horticultural Society.