Red currants (Ribes rubrum) are hardy, deciduous shrubs that grow best in cooler climates that have humid summers. The red currant is a multiple-stemmed bush that usually grows up to 5 feet tall and wide, producing chains of small, edible bright-red berries that ripen in July. Red currant fruits are used to make jellies, syrups and wines. The red currant's deep bluish-green leaves also add interest to landscapes throughout the spring, summer and autumn. The currant berries grow on spurs of 2- or 3-year-old wood.
Water your red currant bushes deeply and slowly two or three times per week during the spring until you harvest the fruits. Reduce the watering frequency to just once per week throughout the rest of the fall and once per month or two during winter.
Feed your red currants once each year in spring with 4 oz. of nitrogen and ½ oz. of potassium per square yard. Don't use potassium in the potassium chloride form.
Spread a 3-inch layer of organic mulch on the ground around the red currant bushes. Spread the mulch to cover the entire root area and add a new layer of organic mulch each year in the spring.
Prune your red currants once each year in winter to remove any stems that have grown too long and to cut away at the bases any stems that are 3 years old or older. In the first three winters, cut all but two or three stems back to the ground surface.
Harvest the red currants by picking the entire string or "chain" of berries by its stem. Pick the currant berries about three weeks after they achieve a bright or deep red color, if you're eating them fresh. If you're going to store the currants, allow them to dry on the bushes before picking them.