How to Plant and Grow Jostaberries

Get essential tips for planting, growing, and harvesting cold-hardy and productive jostaberries.

<p>Flowerphotos / Getty Images</p>

Flowerphotos / Getty Images

Deep purple jostaberries produce pounds of marble-size, sweet and tangy fruit in mid-summer. Relatively new to the berry patch, jostaberry bushes debuted in 1977 and are a cross between exceptionally tart gooseberries and sweet currants. Grown for their reliable productivity in cold regions, jostaberries tolerate temperatures as low as -40°F. Plan to plant two different cultivars of this thornless shrub for the best fruit set. Varieties with red and deep purple, almost black berries are available. The long-lasting fruit stays on the bush for weeks maintaining good quality, provided it is protected from birds. Jostaberries are sweet enough to eat fresh and useful in preserves, sauces, pies, and juiced for beverages.

Where to Plant Jostaberry

The hardy shrubs will fruit best in a location that receives at least 8 hours of bright, direct sun a day, but it will tolerate partial shade. Fruiting will likely be reduced slightly in shaded locations. Although consistently moist, fertile, well-drained loamy soil is best for jostaberry, this adaptable shrub will grow in clay and infertile soil (with reduced fruiting and overall growth likely). A great edible plant for wildlife, it can be planted in less-than-ideal situations and still provide valuable food for birds and small mammals.

How and When to Plant Jostaberry

Jostaberries are sold as potted shrubs at local garden centers, or commonly as bareroot plants from mail order sources. Plants are self-fruitful and will produce a crop if just one plant is growing in a location, but researchers have found that fruiting usually increases when two plants are present. Choose two different cultivars, if possible. Plant shrubs 3 to 4 feet apart.

Plant potted shrubs in spring or early summer by digging a planting hole that is slightly wider than the container. The depth of the planting hole should be equal to the depth of the root ball. Situate the plant in the planting hole so that the top of the root ball is level with the surrounding grade. Backfill the planting hole, tamping the soil in lightly around the root ball. Water the newly planted shrub well and spread a 2-inch-thick layer of mulch over the root zone to help preserve soil moisture.

Plant bareroot jostaberry plants in early spring. Dig a planting hole slightly wider than the root mass and nearly as deep as the mass is long. Form a mound of soil in the planting hole and spread the roots out over the mound. Carefully backfill with soil and tamp the soil lightly to secure the plant in place. Water the bareroot plant well and spread a 2-inch-thick layer of mulch over the root zone to help preserve soil moisture. Bareroot plants grow best with frequent, regular watering for the first couple of months after planting. Aim to water a bareroot jostaberry weekly, delivering about a gallon of water each time.

Care Tips

Light

Jostaberry grows best in full sun (at least 8 hours of direct, bright sunlight). Plants will grow in part shade, but you'll likely get fewer berries. Special note: in USDA Hardiness Zones 6, 7, and 8 jostaberry benefits from afternoon shade. This cold region plant doesn’t tolerate the intense summer heat in warm zones well.

Soil and Water

Jostaberry grows best in fertile, well-drained soil. Soil that is loose and rich in organic matter is ideal for this productive shrub. Improve soil structure and fertility by mixing in a 2-inch-thick layer of well-decomposed compost in the soil before planting, and then reapply annually around the base of the plant in spring.

Water jostaberry as needed during dry spells. Shrubs will produce the most berries when they receive about an inch of water a week.

Temperature and Humidity


Jostaberry tolerates low winter temperatures well, withstanding down to -40°F. While jostaberry has excellent cold hardiness, it is not as tolerant of summer heat. In Zones 6, 7, and 8, shade in the afternoon can help keep the plant cooler. Jostaberry plants growing in these warmer regions don't fruit as well as plants growing in colder zones.

Fertilizer

Jostaberries don't require fertilizer to grow and produce fruit, but they will be more productive with an annual application of a 10-10-10 general garden fertilizer. Spread fertilizer around plants in spring as recommended on the package.

Pruning and Harvesting

Annual pruning is required for good fruit set. Jostaberries bear fruit on two- and three-year-old wood. In late winter or early spring, prior to buds swelling, remove all wood more than three years old. Cut wood back to the base of the shrub. Also, thin out younger wood so the resulting bush has three upright canes of each three-, two-, and one-year-old wood.

Jostaberries are ready to harvest when they are fully colored and soft to the touch. Berries will hang on the bush for weeks and maintain their taste and texture. Harvest berries all at once as soon as they are ripe, or harvest over a few days whenever you want to use them.

Pests and Problems

Birds love jostaberries, especially when they are almost fully ripe in mid- to late summer. Cover bushes with woven bird netting, available at garden centers, when berries are still green. The netting will prevent birds from nabbing the fruit while it continues developing. Remove the bird netting prior to harvest and store it in a cool, dry place for use the following year.

How to Propagate Jostaberry

Jostaberry can be propagated from stem cuttings taken from young canes. Root the stem cutting in moist potting mix and a bright, sunny location. Water the cutting regularly and transplant it into the garden when it has a well-developed root system. Spread a layer of mulch around the young plant in the garden to slow down soil moisture loss.

Type of Jostaberries

‘Jostine’ is a high yielding cultivar with large black berries. It's known for its excellent flavor. ‘Jostine’ grows 3 to 5 feet tall and 3 to 4 feet wide.

‘Orus 8’ is a cultivar prized for its improved flavor compared to the original jostaberry. The purple-almost-black fruit is shiny and about the size of a marble.

Companion Plants

Plant jostaberries alongside their cousins currants and gooseberries. These unique and rare berry types all thrive in cool regions, overwinter reliably in areas with very cold winters, and produce bountiful crops of tiny, tasty fruit. While their hardiness and growth requirements are similar, the flavor of each plant’s berry is unique. Gooseberries are intensely sour while currants are delightfully sweet and jostaberries fall in the middle of the sweet-sour spectrum.

Frequently Asked Questions

How much fruit does a jostaberry shrub produce?

<p>Jostaberries, like gooseberries, are known to be excellent fruit producers. Expect jostaberry to begin producing fruit the second or third year after planting. Plants will come into full fruit production four or five years after planting. One plant will produce 4 to 8 quarts of fruit.<br/></p>

How do I prune a jostaberry bush?

<p>Late winter is the best time to prune the shrub because the structure of the leafless stems is clearly visible. Begin by removing all dead, crossing, or broken wood. Next, remove all wood that is 4 years old or older. If you are pruning in winter and not able to easily determine the age of the wood, selectively remove one-third of the largest woody stems. Prune the plant again in late summer, cutting out any large stems that did not produce fruit.</p>

What does jostaberry taste like?

<p>The marble-size berry has a sweet flavor with a tangy tartness. The complex flavor creates delicious jams, pies, and juice for beverages. Harvest jostaberries when they are fully colored and soft for maximum flavor. </p>