Black currant

Family

Grossulariaceae

Habit

Shrub

Height

1.8 m

Spread

1.5 m

Growth

fast

Lifespan

30 years

First yield

after 2 years

Productive years

10–20 years

Yield per plant

up to 4 kg a year

Yield in cultivation

up to 5 t/ha

Energy yield

200 kcal per m² a year

Hardiness

zone 5–8

Shade tolerance

partial shade

Soil

Sand, Silt, Loam

Soil moisture

semi-dry – very moist

pH

5.5 – 7

Synonyms

Johannisbeere

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Edible: The black, pea-sized berries ripen in July and August and taste tart and astringent, with the characteristic powerful aroma. Fully ripe fruit is best raw, but it works just as well in purees, jams, jellies, nectar and juice; cassis liqueur in France and Aufgesetzter in Germany both grew out of it. The vitamin C content is exceptionally high, ranging from 80 to 350 mg per 100 g depending on variety and site and averaging around 180 mg — and it largely survives cooking, which makes the species almost unique among soft fruit. Young leaves lend a spicy note to herb and vegetable soups in April and May, and dried they make an infusion.

Medicinal: In folk medicine the leaves of the blackcurrant are traditionally used for rheumatism, gout, whooping cough and spasmodic cough. In the Middle Ages the fruit and wood were also regarded as a remedy for gout. Pharmaceutically the leaf constituents are of interest: rutin, essential oil, tannins and vitamin C. What is documented here is the traditional use, not a proven efficacy.

Other uses: A fixed oil is pressed from the seeds; valued for its gamma-linolenic acid content, it goes into skincare products, usually stabilised with vitamin E against oxidation. An extract of the flower buds is a prized raw material in perfumery. The leaves yield a yellow dye and the fruit a blue-violet one, and leaves are added to the jar when pickling vegetables. Beyond the fruit harvest the species is useful as a hedging shrub: it grows densely, tolerates thinning cuts, and serves in field hedges and roadside planting as cover for birds and as an understorey shrub.

The blackcurrant is undemanding as long as the soil stays nutrient-rich and evenly moist; it prefers heavy, humus-rich loam to light sandy ground that dries out in summer. On pH it is more flexible than often claimed — it thrives anywhere from slightly acid to mildly alkaline. Full sun gives the heaviest crops, but half shade is accepted without a drop in yield. The wood is hardy to about -28 °C, whereas the April flowers are vulnerable to late frost. Since the fruit is borne mainly on one-year-old wood, the oldest stems are cut out at ground level after harvest so that young basal shoots can take over. Do not plant near five-needled pines: Ribes species are an alternate host of blister rust.

The blackcurrant is among the easiest soft fruits to propagate. Hardwood cuttings are standard: in late autumn or winter, cut pieces about twenty centimetres long from well-ripened one-year-old shoots and insert them at an angle, deep enough that only two or three buds show. They root reliably by spring; the deep planting is deliberate, so that the bush later comes up multi-stemmed from the ground. Softwood cuttings under mist work in summer. Shoots pegged down in an arc and mounded up root as layers within one season. Seed is used only in breeding: it needs about three months of chilling, then germinates readily and stays viable for many years — but seedlings do not come true.

Early in the year the shrub is valuable to insects: the hanging flower racemes open in April and May and attract roughly a dozen wild bee species collecting nectar and pollen, none of them specialised. As larval food the species matters more — about thirteen moth and butterfly species feed on the leaves, a good third of them exclusively on currants. Birds take the ripe berries readily, and because the seeds pass through digestion unharmed, they spread the species across the landscape. In hedges the densely branched shrub also provides cover and nesting sites.

Features: easy to care for, nitrogen-hungry, tolerates high soil moisture; cultivated in central Europe since the 16th century and probably far longer in north-eastern Europe; best fruit on one-year-old shoots; also trained as a standard; several varieties together increase yield; crossing with gooseberry, with the North American Ribes divaricatum bred in, produced the thornless jostaberry (Ribes x culverwellii), on the market since 1977; green-fruited Finnish varieties lack the harsh aftertaste: 'Vertti', 'Venny' and the large-berried 'Vilma'

Eurasia, from western Europe to Manchuria. The natural range covers the temperate and boreal zones, reaching Lapland in the north and Armenia and the Himalaya in the south, and continuing east through the Caucasus and western Siberia into Mongolia. In the Alps the species climbs remarkably high: records from the Rubihorn in the Allgäu reach 1,930 m. Where the original range boundary ran in central Europe can no longer be reconstructed, because seedlings of cultivated varieties have been escaping into wild populations for centuries. Germany therefore treats the species as native, while Switzerland classes it as a neophyte.

The blackcurrant is a plant of wet woodland. It grows in alder carr, in the willow thickets of damp hollows and in floodplain forest, where soils are nutrient-rich and flooded from time to time. It favours peaty to clayey ground that stays permanently moist to wet, with a slightly acid to neutral reaction. In phytosociological terms it is a character species of the tussock-sedge alder carr and also occurs in grey willow scrub and in hardwood floodplain woodland. Its pronounced preference for moisture explains why it tolerates waterlogging in the garden that defeats other soft fruit. It does not need full light — it comes from the half-shaded woodland edge.