Rare jostaberry is easy to grow

At its best, jostaberry combines the large size, sweet flavor, and disease resistance of the best gooseberries with the lack of thorns and extremely high vitamin C content of black currants.

Starting with a 'mule'

A Mr. Culverwell of Yorkshire, England, is credited with producing the first such hybrid, in 1883, and many amateurs repeated his success in the decades that followed. There was just one problem with all these hybrids: They all grew well, but none ever fruited.

Just as the horse and the donkey produce the sterile mule, gooseberry and black currant are close enough kin to mate, but not to produce fertile offspring.

But success with a fruiting jostaberry was on its way in Germany, where both the gooseberry and the black currant are popular fruits. After numerous false starts, Dr. Rudolf Bauer overcame the sterility by treating the hybrid buds with colchicine, an extract from the autumn crocus that can cause chromosomes to double.

A few branches flowered and fruited, and seeds from those fruits were planted. The resulting fruitful plants were named jostaberries, the name itself a hybrid of the German words for currant (Johannisbeere) and gooseberry (Stachelbeere). Dr. Bauer actually had also thrown into his hybrid another ingredient, the Worcesterberry.

The josta family

Dr. Bauer didn't get just one hybrid for his efforts; he got a few of them. But when the plants were first introduced into this country in the 1980s, all were sold merely as "jostaberry."

Buying one of these plants was almost as much a shot in the dark as would be buying an "apple" tree, rather than a McIntosh, a Cortland, a Red Delicious, or any other specific variety of apple. Some of Dr. Bauer's jostas were more fruitful or otherwise better than the others.

Rarely do nurseries offer specific varieties of jostaberry by name, such as Jostagranda and Jostina. Jostaberries fruit at a young age, so it's worth the risk of trying one that lacks a specific name.

Pretty and easy

Aside from their fruits, which have a unique, rich flavor, jostaberry leaves unfold early and retain a rich, forest-green color throughout the season. The plants grow happily in any reasonably fertile and well-drained soil, and bear well even in some shade, which is rare for a cultivated fruit (gooseberry and black currant excepted).

The only care you need to give a jostaberry plant is annual pruning. Like the mule, all jostaberry plants exhibit hybrid vigor, increased by their double set of chromosomes. Shoots grow vigorously and each plant fills a spaceabout six feet by six feet.

Pruning keeps a plant from growing too large, and also removes potential fruits, forcing the plant to concentrate its efforts on fewer fruits which then taste better and grow bigger.

On a mature bush, the plan is to cut back one or two of the oldest shoots to ground level in winter. Of course, there is one more job: Harvest the berries, 10 pounds or so from each full-size bush. No need to rush the harvest, because the ripe berries wait for you on the bush.