Jostaberry

Jostaberries are vigorous, thornless shrubs that grow quickly to five or six feet tall and wide. They are remarkably low-maintenance and resistant to many diseases that plague their parent species. Plant in full sun to partial shade in well-drained, fertile soil enriched with compost. Space plants five feet apart for hedging or six to eight feet for individual bushes.

Plant bare-root jostaberries in late autumn or early spring. Water well during the first growing season to establish a strong root system. Jostaberries are self-fertile, but yields improve significantly when a black currant or gooseberry is planted nearby for cross-pollination.

Prune annually in late winter by removing about one-quarter of the oldest branches at ground level, along with any weak, damaged, or crossing growth. This keeps the bush productive with a mix of young fruiting wood. Mulch generously with compost or bark chips. Jostaberries are moderate feeders; apply a balanced organic fertilizer in early spring. These hardy, disease-resistant plants are among the easiest fruit bushes for home gardeners to grow.

The jostaberry (Ribes × nidigrolaria) is a relatively modern horticultural achievement, the product of deliberate interspecific hybridization work conducted in Germany over much of the 20th century. The breeding goal was to combine the superior flavor and vitamin content of the blackcurrant (Ribes nigrum) with the vigor, large fruit size, and thornlessness of the gooseberry, while incorporating disease resistance from the American spreading gooseberry (Ribes divaricatum).

The theoretical possibility of crossing blackcurrants and gooseberries had been explored since the late 19th century, but early attempts produced mostly sterile or unproductive hybrids due to the chromosomal differences between the species. Serious systematic breeding work began in Germany in the 1920s at what would later become the Max Planck Institute for Plant Breeding in Cologne. Researchers eventually discovered that including Ribes divaricatum — a tetraploid North American species — in the cross allowed the production of fertile, vigorous offspring that combined traits from all three parent species.

After decades of selection and evaluation, the Max Planck Institute released the first commercial jostaberry cultivar in 1977, naming it after a combination of the German words for its parent species. The release was met with considerable horticultural interest across Europe, particularly in Germany, Switzerland, the Netherlands, and later in the United Kingdom and Scandinavia. Commercial orchards were established in Eastern Europe, particularly Poland and the Czech Republic, to supply the fresh and processed fruit markets.

In North America, jostaberry cultivation gained interest partly because of its resistance to white pine blister rust, a fungal disease for which Ribes species serve as an alternate host and which led to widespread bans on blackcurrant cultivation across many US states in the early 20th century. Jostaberry's demonstrated resistance to this pathogen has made it legally cultivable in some states where blackcurrants remain restricted.

Today, jostaberry remains a specialist crop rather than a mainstream commercial fruit, occupying a niche as an exceptional home garden plant and small-scale specialty crop. Its combination of large, flavorsome fruit, disease resistance, thornlessness, and cold hardiness has earned it a dedicated following among home gardeners and fruit enthusiasts across temperate regions of Europe, North America, and New Zealand.

Jostaberries grow well in a range of soil types but prefer fertile, moisture-retentive, well-drained soil with a pH of 6.0 to 6.8. Amend poor soils with generous compost before planting and top-dress annually. Apply a balanced organic fertilizer such as 5-5-5 in early spring. Avoid excessive nitrogen which promotes dense leafy growth at the expense of fruit. Potassium supports fruit development; supplement with wood ash or greensand if soils are potassium-deficient.

Jostaberries ripen in midsummer, turning from green to dark purple-black when ready. Unlike black currants, individual berries within a cluster ripen at different times, so multiple harvests over two to three weeks are typical. Pick berries when fully dark and slightly soft. They are larger than black currants, about the size of small grapes, making them easier to harvest. Jostaberries detach cleanly from the strig when ripe. Taste-test before bulk harvesting, as under-ripe berries are quite tart.

Fresh jostaberries keep in the refrigerator for up to one week. Freeze by spreading on trays and transferring to bags for up to twelve months. Jostaberries make excellent jam, jelly, and fruit syrup with a flavor that blends the richness of black currant with the brightness of gooseberry. They work well in pies, crumbles, and smoothies. Their high pectin content means jam sets easily without added pectin. Jostaberry wine has a deep color and complex flavor.

Jostaberries have a milder, sweeter flavor than black currants with a gooseberry brightness, making them more versatile in the kitchen. They are excellent fresh when fully ripe, which distinguishes them from the more astringent black currant. Use them in jams, pies, smoothies, and fruit sauces. They pair well with apples and other berries in mixed preserves. Their juice makes a distinctive deep purple beverage rich in vitamin C.