Currants (Ribes spp.) are related to gooseberries. In addition to the black currant there is also the red, pink, white and Asian currant; all are different species.
As you may suspect, currants are not a tropical plant. According to the USDA map zones, they are best adapted for zones 3-5 where temperatures may get down to minus 40 degrees Fahrenheit (-17 Celsius). Two states where currants are commercially grown are New York and Michigan. In addition, they require between 800 and 1600 hours below 45 degrees Fahrenheit (7 Celsius) during the winter in order to complete their chilling requirement and begin spring growth.
Some currants are being successfully grown in the coolest parts of the San Francisco Bay Area and in coastal Northern California. It is questionable whether they will do well in Southern California or in Hawaii. On the Big Island of Hawaii, it is possible that they could grow at high elevations, but there is no confirmation yet.
Currants are deciduous shrubs, at least on the Mainland, growing about 5 feet tall and wide. They like morning sun and since the leaves readily sunburn and are susceptible to wilt at high temperatures, some shade in the afternoon is preferred. Placing 2-3 inches of mulch around the planting is desired.
Currants can withstand ocean winds, but the salt air will burn the leaves. Shrubs must be pruned annually to increase yields and rejuvenate plants. Birds feeding on ripening fruit along with the powdery mildew fungus are potential primary problems.
Currants are easily propagated by hardwood cuttings of one year old wood; rooting hormone will help. Softwood cuttings also root easily.
Black currants are truly a nutritious food. They are rich in many phytonutrients, antioxidants, vitamins, essential fatty acids and minerals. They have twice the potassium of bananas, four times the vitamin C of oranges, and twice the antioxidants of blueberries. Black currants contain anthocyanins, potent antioxidants which are responsible for the color of the fruit. They are known to reduce inflammation and the effects of arthritis in the body, similar to aspirin.
Note: Black currants and all currants are unrelated to the small raisins sold commercially as dried or black currants. These raisins are made from the black Corinth grape, a small grape shipped for centuries from the Greek port of that name.
For those wanting to try currants in Hawaii, an Internet search will yield several nurseries that sell young plants. Two are Miller Nursery - millernurseries.com and Hidden Springs Nursery -hiddenspringsnursery.com.
