Days to germination: Not grown from seed
Days to harvest: 1 year
Light requirements: Full sun or slight shade in warmer climates
Water requirements: Regular watering
Soil: Rich with organic matter, added potassium
Currants come in three colour varieties: black, red and white. They are not that different, but the black ones are more tart and are more commonly used for jams or cooked uses. Red currants are eaten fresh as well as cooked, though the little seeds inside can be a bit awkward. A very popular fruit in the UK, the currant is starting to gain fans in North America as well. Currant juice is used in a variety of recipes including several liqueurs and cordials.
The berries are high in vitamin C and antioxidants. Currants look much like blueberries, an shouldn’t be confused with a variety of raisin that is commonly called a “currant”. They are not the same fruit at all.
Currants will grow best in cooler areas, from zones 3 to 5 but they can be grown farther south if planted in a slightly shaded location.
Currants are usually started from seedlings or cuttings, rather than from seed. Plant your cuttings out in the early spring or late fall. They should be around 4 to 6 feet apart if you’re planting more than one.
Your currants need to be planted in a sunny location, and in a spot where their mature height of 6 feet won’t shade anything else in the garden. For very warm regions, you can allow your bushes to grow in a slightly shaded area to keep the heat of the sun off the plants.
Dig a hole large enough to hold the seedling’s roots without crowding them, and add extra compost or aged manure. Trim the above-ground portion of the cane to 12 inches long right after planting. This will force the plant to grow a stable root system before budding leaves or fruit.
Like raspberries and blackberries, currants will require extra care through the season with regular pruning. Your bushes will produce the most berries on year-old branches, so you should always leave new growth and cut back the canes you just harvested from. Another good pruning tip is to cut back some of the branches from the center of the bush, to allow for more light. The ideal shape for a currant bush is a like a “open goblet”. For more berry production, keep each bush limited to 10 to 14 healthy canes each season.
A yearly feeding in the spring is a good idea, particularly with a potassium-rich fertilizer. Natural seaweed-based fertilizers are ideal for currants. Mulch around the base of the plants to help retain moisture and keep the roots cooler. Adding pine needles to the mulch will add some necessarily acidity that currants need. Black currants need more feeding than red or white ones, and would be happy with a second fertilizing around late summer.
Currants do produce fairly large bushes but can be successfully grown in a large enough container. Three feet across by 2 feet deep should be adequate for a single currant bush.
You’ll have to be a bit more aggressive with your pruning so that it doesn’t outgrow the pot. Each plant should be limited to 4 or 5 branches each. With a limited number of canes, you may need to add some support to keep them upright.
Pests and Diseases
Once the berries start to ripen, you will have to compete with the birds for your harvest. A mesh cover can help keep your currants safe, and it helps to get them picked as soon as possible as well.
Aphids are tiny insects that can cause serious problems when they are in large numbers. Take a close look at your currants if the new leaves seem to be curling instead of leafing out. A spray with a regular insecticide should help clear them out. Aphids can kill new leaves and also spread plant diseases because of the way they puncture the plant’s veins. It’s always best to deal with aphids even if they seem harmless at first glance.
Currants grown in North America can be targeted by the currant fruit fly, though its not a common problem elsewhere. The adult looks much like a small housefly, and the female lays her eggs in the newly forming berries. The larvae hatch and eat the berry from the inside. You will notice individual berries looking ripe ahead of all the others (either turning black or red), and eventually dropping off.
Though they are ruined, you should pick up as many dropped currants as possible to prevent the worms from overwintering in the soil and starting the cycle again in the spring. Spraying the plants with insecticide earlier in the spring can help reduce the number of flies.
For anyone growing currants in the UK or Europe, the gall mite is going to be be your biggest problem. The tiny mites get under the surface of the leaves or stems, and cause a large swelling or “gall” to form. If enough are present, it can severely stunt the plant. The larger issue is that the mites can spread reversion virus, which will kill your plants.
Harvest and Storage
Depending on the age of your seedling, you may not get any fruit the first year after you plant. But by the second year, the branches from the first year should start to blossom and produce berries.
An average and healthy currant bush can produce between 6 and 10 pounds of berries each season.
You should harvest your currants about 2 to 3 weeks after they first turn their mature colors (black, red or light pink). The easiest way to harvest them is to pick the entire sprig of fruit, and pull off the individual berries later in the kitchen. If the weather was the least bit wet when you picked your berries, dry them off with paper towel as soon as you bring them inside. They can go moldy very quickly if left wet.
Fresh currants can be stored in the fridge for 3 or 4 days. You can also freeze the whole berries, and then they will keep for several more months.