Jostaberry

Family

Grossulariaceae

Habit

Shrub

Height

3.4 m

Spread

2 m

Growth

very fast

Lifespan

20 years

First yield

after 2 years

Full yield

after 4 years

Productive years

10–20 years

Hardiness

zone 6–9

Shade tolerance

partial shade

Soil

Sand, Silt, Loam

Soil moisture

moist – very wet

pH

5.5 – 7

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

Edible: The berries hang three to five together in short clusters, are deep black and reach roughly gooseberry size. In flavour they sit between the parents: the aroma recalls blackcurrant but is milder and distinctly sweeter, without its astringent aftertaste. Vitamin C content is high. Ripening runs from mid-June into July and, unlike currants, the berries within a cluster ripen unevenly — two or three pickings give the best quality. They are pleasant eaten raw; processed they make dark jams, jellies, juices, liqueurs and wine. They freeze without appreciable loss of quality.

Other uses: Because it stays thornless, branches densely and produces no suckers, the jostaberry makes a good low productive hedge along paths and play areas — where a gooseberry would be a source of injury. Planted about a metre and a half apart in the row and kept only to height, it forms a dense, edible screen. Nurseries also offer it as a standard grafted on golden currant (Ribes aureum); such standards suit containers but need a permanent stake and suffer more from drought than bushes on their own roots. The strong berry pigment stains fabric and pale grouting permanently.

Site: Sun brings sugar and yield; part shade is tolerated and delays ripening by about a week. Shelter matters more than light: the bush flowers early, and cold draught or late frost during flowering costs most of the set. At 1.8 to 2 metres high and wide the jostaberry is considerably larger than a currant — allow 2.5 to 3 metres between plants or it goes bare at the centre. Unlike gooseberry it is thornless, so it can safely be placed beside paths and within reach of children. Being a hybrid it is largely self-fertile, though a second bush or a blackcurrant nearby noticeably improves the set. Care: Do not prune for the first two or three seasons; let the bush build its framework. Then remove one or two of the oldest stems at ground level each year; the heaviest crops come from two- and three-year-old wood, older stems go bare. Pruning straight after harvest is easier to judge than winter pruning, because the fruiting wood is still recognisable. Compost in spring and a mulch keep the root zone evenly moist — the shallow-rooted bush responds to summer drought by dropping fruit. It is markedly more resistant to American gooseberry mildew and white pine blister rust than either parent, which makes it an easy garden plant. Birds will harvest alongside you; netting from first colouring secures the crop.

Sowing seed is pointless with the jostaberry — as a hybrid its offspring segregate, and seedlings are almost always poorer than the mother plant. Propagation is entirely vegetative and as simple as with blackcurrant. Hardwood cuttings are usual: between October and February cut lengths of about 20 centimetres from well-ripened one-year-old wood and push them into loose, weed-free soil deep enough that only two buds show. By the following autumn they are rooted and can be moved. Layering is equally reliable: bend a low shoot down in spring, cover it with soil and separate it from the parent in the autumn of the following year. Plant breeders' rights apply to some of the newer cultivars.

The inconspicuous greenish flowers open early, usually from April, and supply nectar and pollen at a thin point in the garden year. Bumblebees are the most important visitors because they fly at low temperatures and in dull weather; honeybees and early solitary bees such as mining bees follow. No specialised species can be expected on a garden hybrid, and Ribes species are in any case not significant larval food plants in Central Europe. The value for birds is more solid: the dense, thornless bush offers blackbirds and warblers sheltered nest sites, and the black berries are taken from mid-June — competition rather than pleasure from the gardener's point of view. Old unpruned bushes with some dead wood also house pith-nesting solitary bees.

Notable: cross of blackcurrant+gooseberry(+Ribes divaricatum); thornless; far more resistant to mildew+blister rust than either parent; 1.8-2m high+wide, spacing 2.5-3m; crops on 2-3 year wood; ripens mid-June to July, unevenly (2-3 pickings); cultivars: 'Josta'(1977), 'Jocheline', 'Jogranda', 'Jostine', 'Rikö';

A garden hybrid with no natural range. The jostaberry arose from crosses between blackcurrant (Ribes nigrum), gooseberry (Ribes uva-crispa) and the North American Ribes divaricatum. Erwin Baur began the work in 1922, aiming to combine the cropping power of the currant with the fruit size of the gooseberry and genuine mildew resistance. It took decades to reach the market: Rudolf Bauer introduced the cultivar 'Josta' at Ahrensburg in 1977, while related hybrids were bred in parallel in East Germany. The jostaberry is now grown across Central Europe in gardens and on a commercial scale.

As a garden hybrid the jostaberry occurs nowhere in the wild; its site requirements follow from its parents. Blackcurrant grows in damp alder and floodplain woodland and along the edges of carr across Eurasia, gooseberry in open deciduous woodland, hedgerows and on rocky scree in the uplands. The jostaberry accordingly wants a deep, humus-rich and evenly moist soil of the kind found beneath woodland margins, but tolerates far more sun than either parent. Waterlogging and shallow, quickly drying soils are the commonest cause of weak growth and fruit drop.