Jostaberry

Jostaberry is an interspecific hybrid whose development began at the Kaiser Wilhelm Institute in Berlin in 1926 under Paul Lorenz. The project aimed to combine black currant (Ribes nigrum) with gooseberry, but initial crosses produced sterile offspring. Over 1,000 F1 hybrids were created; only eight survived World War II. The program eventually transferred to the Max Planck Institute for Plant Breeding Research in Cologne, where Dr. Rudolf Bauer achieved fertility by using colchicine to produce tetraploid plants. The hybrid incorporates three Ribes species: nigrum, uva-crispa, and divaricatum, whose thornless character is encoded in the hybrid species name nidigrolaria. Bauer released the first stable cultivar under the name Josta in 1977, blending the German words Johannisbeere (black currant) and Stachelbeere (gooseberry). The patent has since expired. Jostaberry represents a landmark in Ribes breeding — a fertile interspecific cross that took over fifty years to stabilize and combines black currant’s cold hardiness and nutritional density with gooseberry scale and thornless canes.

Jostaberry's shallow, fibrous root system makes consistent soil moisture the most critical management variable — drought stress during fruit development shrinks berry size and reduces yield more than almost any other factor. Rich loam with good drainage is ideal, but the plant tolerates clay and sandy soils if organic matter is worked in to buffer moisture and pH. Aim for a soil pH between 5.5 and 7.0; strongly acid soils below 5.5 limit nutrient uptake and favor root rot. Full sun drives the best yields, but the plant handles partial shade, making it adaptable to the east or north sides of buildings and under open woodland canopies. Water needs run roughly 1 to 2 inches per week through the harvest window in late June through early August, particularly in humid-summer climates where foliage disease pressure coincides with ripening. Avoid overhead irrigation, which wets foliage and promotes gray mold on clusters. Mulch 3 to 4 inches deep to conserve moisture, moderate soil temperature, and reduce the splash-dispersal of fungal spores from the soil surface.

USDA Hardiness Zone: 3-8
AHS Heat Zone: 2-7
Chill Hours: 1000-1500
Sun Requirements: Full Sun to Partial Shade
Soil pH: 5.5-7.0
Soil Type: Rich loam, sandy loam; tolerates most soil types if well-drained
Soil Drainage: Well-drained
Water Requirements: Medium; keep evenly moist but not waterlogged
Drought Tolerance: Low
Plant Spacing: 5-6 ft apart
How to Prune: Prune in late winter/early spring (March) before new growth starts. Remove dead or diseased wood. Thin old canes after year 3; jostaberry fruits on older wood so keep young shoots on established branches cut short. Renewal prune every 3-4 years by removing oldest canes at ground level.

At maturity, jostaberry builds a multi-stemmed, upright-to-arching shrub typically 5 to 8 feet tall and equally wide, making it one of the larger Ribes species in cultivation. The thornless canes make harvest and pruning far safer than traditional gooseberries, allowing growers to work inside the canopy without protective clothing. Canes emerge from the crown in a vase pattern and arch outward as they lengthen, creating a dense, self-supporting structure that works well as an informal edible hedge or a specimen planting at the back of a mixed border. Foliage resembles gooseberry leaves in shape but larger, with three to five lobes; fall color is a clear, bright yellow. Because the plant fruits primarily on two-year-old and older wood, maintaining a mix of young and mature canes through renewal pruning determines productivity. Every three to four years, remove the oldest canes at ground level in late winter to encourage vigorous replacement shoots. The fibrous, surface-feeding roots mean mechanical cultivation closer than 12 inches to the base risks root damage; a permanent mulch ring is preferable.

Mature Height: 5-8 ft tall
Mature Spread: 5-8 ft wide
Growth Habit: Upright, multi-stemmed deciduous shrub
Growth Rate: Moderate to Fast
Foliage Type: Deciduous
Food Forest Layer: Shrub
Fall Foliage Color: Clear yellow
Thorns?: No
Attracts Wildlife: Bees, butterflies, birds
Life Span: 15-20+ years with proper renewal pruning

Jostaberry is self-fertile, so a single plant will set fruit, but adding a compatible Ribes companion nearby consistently pushes yields higher through cross-pollination. Bloom opens late March through mid-April in temperate climates — among the earliest of the fruiting shrubs — making it dependent on early-season pollinators like mining bees and queen bumblebees. Flowers emerge in clusters of three to five, with distinctive bicolor maroon-pink and creamy-white petals on short racemes. Both insects and wind transfer pollen. Any other currant or gooseberry blooming at the same time qualifies as a pollination partner; Consort Black Currant and Crandall Black Currant are particularly compatible companions that also share jostaberry's early bloom window. Avoid planting in frost pockets where late cold events can damage open flowers; air drainage on a gentle slope reduces this risk.

Bloom Season: Very Early
Bloom Window: Late Mar - Mid Apr
Pollination Requirements: Self-fertile; cross-pollination improves yield
Pollination Mechanism: Insect-pollinated (bees) and wind
Flower Color: Maroon-pink and creamy white (bicolor); small, in clusters of 3-5
Ploidy: Tetraploid (4x)

Ripening runs from late June through early August, with berries progressing from light green through deep reddish-black to jet black at peak maturity. Size runs 0.5 to 0.75 inch in diameter — noticeably larger than black currant but smaller than most gooseberry cultivars — with a firm, slightly leathery skin and persistent blossom-end calyx characteristic of gooseberry parentage. Flavor is sweet-tart, with the fruity brightness of gooseberry blending into the deeper, musky undertones of black currant; the balance is smoother and less astringent than either parent species eaten raw. A mature bush yields 10 to 15 pounds annually, with clusters loosely held on the cane rather than tightly packed, which simplifies hand-harvesting. Refrigerated shelf life is 5 to 6 days; the berries freeze well and hold flavor for 12 months. Culinary applications span raw eating, jams and jellies (the moderate pectin content sets reliably), pies, sauces for savory dishes including lamb and pork, syrups, wine, and smoothies. High vitamin C and anthocyanin content make the fruit a nutritionally dense fresh or preserved food.

Ripening Season: Mid
Harvest Window: Late Jun - Early Aug
Fruit Size: 0.5-0.75 inch (intermediate between blackcurrant and gooseberry)
Flavor: Sweet-tart; reminiscent of gooseberry with blackcurrant undertones; smooth and fruity
Fruit Color: Dark purple-black (ripens from light green through dark reddish-black to jet black)
Fruit Texture: Juicy, jelly-like flesh; firm skin
Fruit Skin: Firm, slightly leathery; thin; with persistent calyx (blossom end) like gooseberry
Bearing Habit: Bears on older wood (2-year-old and older canes); fruits in loose clusters
Years to Bear: 2-3 years
Yield: 10-15 per mature bush annually
Storage Life: 5-6 days refrigerated; freeze for long-term storage
Culinary Uses: Fresh eating; jams and jellies; pies and cobblers; sauces (savory with meats/fish); syrups and cordials; wine; freezing; smoothies

Jostaberry's most commercially significant trait is near-immunity to white pine blister rust (Cronartium ribicola) — the fungal disease that prompted state-level Ribes planting bans across much of the eastern United States. This high resistance means jostaberry can be legally grown in most formerly restricted states. Powdery mildew (Sphaerotheca mors-uvae) and currant leaf spot (Drepanopeziza ribis) are both well-controlled genetically; expect minimal foliar impact even in humid-summer climates without fungicide intervention. Botrytis fruit rot (Botrytis cinerea) and anthracnose (Colletotrichum orbiculare) are moderate weaknesses. Harvest clusters promptly as they ripen, prune to open the canopy for airflow, and remove fallen fruit to manage gray mold. Thin old canes annually and apply compost mulch to limit anthracnose spore splash from the soil surface. Imported currantworm (Nematus ribesii), currant borer (Synanthedon tipuliformis), and gooseberry fruitworm (Zophodia convolutella) are moderately susceptible pests. Monitor for sawfly larvae in early May; remove by hand or apply spinosad (OMRI-listed) at first sign of feeding. Remove canes with currant borer frass at the base in spring. Currant aphid (Cryptomyzus ribis) pressure is moderate; strong water sprays and parasitic wasps provide sufficient control in most seasons.

White Pine Blister Rust: Very Resistant
Powdery Mildew: Resistant
Currant Leaf Spot: Resistant
Botrytis Fruit Rot / Gray Mold: Moderately Susceptible
Anthracnose: Moderately Susceptible
Imported Currantworm / Currant Sawfly: Moderately Susceptible
Currant Borer: Moderately Susceptible
Currant Aphid: Moderately Resistant
Gooseberry Fruitworm: Moderately Susceptible

• Harvest incrementally: Berries on a single cluster ripen over one to two weeks; pick every few days rather than waiting for the whole cluster to blacken, which reduces gray mold exposure on overripe fruit.
• Gray mold management: After harvest, remove any spent clusters or mummified fruit immediately — Botrytis overwinters on this debris. Thin the center of the shrub every year to keep airflow moving through the fruiting zone.
• Currant borer detection: In spring before bud break, inspect the base of each cane for small entry holes and sawdust-like frass; remove affected canes at ground level and dispose of them off-site to prevent adult moth emergence.
• Rust status check before purchasing: Despite jostaberry's very high resistance to white pine blister rust, some states still require a permit or documentation for any Ribes planting. Confirm your state's current regulatory status before ordering.
• Renewal pruning cadence: Remove the oldest one-third of canes at ground level every three to four years in late February or early March. The plant fruits best on two- and three-year wood; canes older than four years produce declining yields and increase canopy density.

Our 365-Day Plant Guarantee: We ensure that our plants are delivered to you alive and healthy. If your plant does not survive its first year, you're eligible for store credit under these conditions:

1. Your location falls within the appropriate USDA hardiness zone for the plant variety (refer to our hardiness zone map).
2. You maintain the roots' moisture and plant within three days of delivery, following the instructions in our Planting Guide.

If you're concerned about your plant's health, please consult our guide, How to Tell if Your Tree is Dead or Dormant. Remember, our plants are shipped in a dormant state and may leaf out at different times based on their species. To check for plant vital