How to Grow And Care For Jostaberries
Jostaberries are a hybrid of the black currant (Ribes Nigrum), the North American coastal black gooseberry (Ribes Divaricatum), and the European gooseberry (Ribes Uva-Crispa).
Almost black berries are smaller than gooseberries and a bit larger than black currants with a taste between a gooseberry and a black currant. Fruits are edible fresh and often consumed processed in jams, pies, etc. Like blackcurrants, jostaberry fruits freeze well.
When growing jostaberries in small gardens, keep in mind that the ripe fruits can be kept on the bush in good condition through the entire late summer. However, birds like jostaberries and jostaberry bushes must be protected by nets.
Jostaberry grows to a maximum height of about 6-7 feet (1.8-2.1m) and is resistant to a number of common diseases afflicting many other berries.
Jostaberry is very resistant to diseases like blackcurrant leaf spot, American gooseberry mildew, white pine blister rust, big bud gall mite, etc. However, the gardener should always observe the plants and react when necessary.
In areas where diseases prevent the successful cultivation of gooseberries and similar plants, jostaberries can be used as a replacement berry plant - after all, it is a very decorative plant with numerous sweet and sour berries with a strong aroma and fragrance.
Even if one doesn't have issues with gooseberries, currants, and other berries, if You have space, feel free to plant a few jostaberries - they are easy to grow and take care, and after 4-5 years, a good jostaberry bush can easily provide up to 10-12 pounds (4.5-5.5 kg) of berries.
How To Propagate Jostaberries
Propagation is similar to the propagation of gooseberries - seeds can be used, but jostaberries are mostly propagated using cuttings.
In late winter or early spring, 8-10 inches (20-25cm) long cuttings are taken from the jostaberry bushes and planted into the flower pots, filled with good rich soil that is kept wet.
One can also use a rooting hormone, but good results are achieved even without it. Actually, this method can be used almost year long, but late winter and early spring are the best time for propagation using cuttings.
If one needs just a few plants, it is perhaps the best option to buy plants in local garden centers ready for transplanting in a permanent location.
Soil For Jostaberries
Jostaberries should be planted in rich, well-drained, slightly acidic soil. Jostaberries prefer sunny positions, protected from strong winds.
Jostaberry bushes tolerate colder climates - they thrive in USDA zones 3-8 and can withstand temperatures down to -40°F (-40°C). However, if they start too early in spring, late spring frost can damage the flowers.
In late autumn, add aged manure and some organic compost and dig the soil a little bit. In later winter, add again some aged manure, compost, and even some balanced NPK fertilizer, preferably with a gradual release of nutrients.
Jostaberries are very vigorous plants and thrive in moist, rich soil, but too much of nutrients, especially nitrogen, can make them big but weak and prone to diseases.
How To Plant Jostaberries
Jostaberry shrubs are planted 4-5 feet (~1.2-1.5 m) apart and some 5-6 feet (~1.5-1.8m) between the rows.
Pot-grown jostaberries should be planted some 1-2 inches (2.5-5 cm) deeper than the soil level - dig a hole that is a few inches larger than the pot, mix the soil with organic compost, and aged manure, place the root ball in the hole, add fertilized soil and press everything strongly.
Prune shoots down to 2-3 growth buds and water thoroughly.
Place bare root jostaberries in the bucket of not-too-cold water - in the meantime, dig a hole large enough to accept the roots, mix the soil with organic compost and aged manure, place the roots in the hole, add soil, and press firmly.
The bare root jostaberries should be planted ~1 inch (2.5 cm) lower than they were growing before transplanting them.
If the shoots are not already pruned, prune them down to 2-3 growth buds and water them thoroughly.
How To Prune Jostaberries
Jostaberries produce fruit on one and two-year-old canes but also on older wood. However, to keep the bush "open", regularly prune in late winter, before the plants start to grow:
- remove anything that is broken, ill, or crossed with other branches,
- prune half of the young shoots to about 15cm (6 inches) above the ground and leave the other new shoots,
- prune one-third of the older, woody growth to within 2-3cm (1 inch) above the ground.
Note: jostaberries are pruned in order to let the sunlight pass through the bush (prevents disease), stimulate fruit production, and ease the harvest.
One more thing - unlike gooseberries, jostaberries don't have thorns! Mostly - some varieties do have some thorns, but not many.
Jostaberries are fully ripe when they have a sweet and sour aroma and an almost full, deep black color with a very dark reddish tone.
Jostaberries should be consumed fresh, but they are also excellent in pies, jams, juices, etc. They are best consumed with other berries.
Also, they can be preserved well in the freezer.
The most popular Jostaberry varieties include (in alphabetic order):
- Jocheline: late flowering variety, suitable for areas with late frost. Tasty berries, but susceptible to powdery mildew, blister rust, and black currant gall mites.
- Jogranda: large, dark red/violet berries, great harvest, but needs some support for heavily loaded branches. A compact but robust variety that blooms late.
- Josta: strong vertical grow, berries are sweet&sour with complex and strong aroma. Very resistant to black currant gall mites, blister rust, powdery mildew, and leaf spot disease.
- Jostine: high-yield plant with medium to big berries that are kept well on the bush. Good taste as well.
- Orus 8: great tasting berries with few thorns - it is considered one of the best Jostaberry cultivars on the market. Also, very resistant to aphids and fungi.
- Red Josta: high-yield jostaberry cultivar with tasty fruits.
Few Final Words
Jostaberries are easy to grow, they are resistant to cold weather and most pests and diseases, and they taste great, although a little bit specific.
If You have a small garden and a little free space, plant a few jostaberries - they can also be very decorative.
Even if You don't have good soil for the jostaberries, they can be grown in pots, or the soil can be heavily amended with peat moss, aged manure, sand, compost, worm castings, and similar.
Jostaberries are very decorative, high-yield berries, grown as bushes up to 6-7 feet (1.8-2.1m) tall, in USDA zones 3-8. Jostaberries are not too picky about their growing conditions, but they require moist but not waterlogged soil, rich in nutrients and organic matter.
Although Jostaberries can withstand temperatures down to -40°F (-40°C) - and that is rather cold - and although they require some 800-1000 chill hours, Jostaberries can be susceptible to late spring frost, especially when flowering. Hence, growing them in pots and containers in cold and warm areas can yield some great harvests.
Published: February 24, 2023.