Jostaberry

About Jostaberry

Jostaberry is a thornless cross between black currant and gooseberry, with clusters of dark berries that taste like a mild, sweet black currant. It is vigorous, heavy-yielding and resistant to powdery mildew and white pine blister rust (University of Minnesota). It is still a Ribes, so check your state's rules before planting: North Carolina bans all Ribes.

University of Minnesota rates its hardiness excellent to very good in zones 3-5; it is grown through about zone 8 where summers aren't too hot.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Plant once temperatures below 20 F are past (University of Minnesota). Give currant-family shrubs at least 3 feet, and vigorous black-currant types 4-5 feet. Expect fruit 1 to 3 years after planting; fruit forms on 1- to 3-year-old wood.

Soil

Rich, well-drained soil gives the best crops, though currant-family shrubs tolerate marginal soil; test the soil first (University of Minnesota).

Test the soil for pH and nutrients and choose rich, well-drained ground (University of Minnesota).

Feeding

• Each year in late fall: well-composted manure or other nitrogen-rich compost. A few shovelfuls spread around each plant (University of Minnesota).

Keep the canopy open with yearly late-winter pruning, leaving 9-12 canes on a mature shrub (University of Minnesota).

Harvest

Pick when the berries change color and flavor, soften slightly and come away easily; cool them quickly (University of Minnesota). The fruit clings tightly and does not drop (UW-Madison CIAS).

Jostaberry, a gooseberry and black currant cross, is grown like its parents, which give one crop a year in June-July; the berries hold on the bush, so one or two pickings usually do it.

Varieties (4)

Only 4 named jostaberries are documented by sources we could open (USDA GRIN, UMass). Most jostaberries sold in the US are simply labeled "jostaberry," and the University of Wisconsin found plants from different sources were likely the same old clone. Sources do not give zones for single cultivars; the Minnesota Extension rates jostaberry as a group very hardy in zones 3-5.

Pests to watch for

Aphids, Twospotted spider mite

Diseases and problems

Powdery mildew, White pine blister rust

In the kitchen

Good for fresh eating and for cooking and processing (UW-Madison CIAS).

Keeping it: Cool berries quickly after picking; covered in the fridge they keep up to several weeks.

Safety: The sources we checked list no toxic parts, and we found no research-based guidance on pregnancy, drug interactions or allergies. Currant-family plants can host white pine blister rust, so some states restrict them: North Carolina bans growing any Ribes (NC Department of Agriculture); jostaberry itself resists the disease (University of Minnesota).

Pets: Not listed as toxic by the ASPCA