How to Grow Black Currants in Australia

Black currant (Ribes nigrum) is a deciduous fruiting shrub in the currant and gooseberry family, Grossulariaceae, grown for its tart, glossy black berries. It reaches about 1.5 m and can crop for many years where winters turn properly cold, from Hobart and Ballarat to Canberra. The mistake most gardeners make is planting it where winters are too mild to give the chill it needs.

Three mistakes that matter

1. Planting where winters are mild. The fruit buds need winter chilling, so a bush in a warm district leafs up but flowers and fruits poorly. Check your zone under When to plant before buying, and give the plant your coolest sheltered spot.
2. Shortening the young stems. Black currants fruit best on the pale stems that grew the summer before, so trimming their tips cuts off next summer's crop. Remove whole old, dark stems at the base instead, as Pruning and Training explains.
3. Leaving ripening fruit uncovered. Birds and possums can strip a bush overnight once the berries colour. Net it before then with white, wildlife-safe netting stretched taut over a frame, with mesh too small to push a finger through.

When to plant

Plant a bare-root cane while it is dormant, usually from June to August, before the buds break in spring. After that, the bush needs a cold winter every year. Many black currant varieties need up to 1,400 hours below 7°C for the fruit buds to form well.

Avoid frost hollows, because frost on open flowers in spring can cost the crop. If frost is forecast at flowering, cover the bush overnight with fleece and remove it in the morning so bees can reach the flowers.

Site, soil and setup

As a permanent shrub it sits outside any crop rotation, so choose ground where it can stay undisturbed for many years.

Container growing

A pot suits a courtyard or balcony for a few years, although a black currant crops better and lives longer in the ground. Use a pot at least 45 cm wide and 45 cm deep, holding about 50 L of premium potting mix, with drainage holes. Once cropping falls away, plant the bush out in the garden.

• Watering: keep the mix evenly moist through the growing season, checking daily in warm weather and watering whenever it is dry 5 cm down. See watering pots in summer.
• Feeding: mix a controlled release fertiliser for containers into the potting mix at planting, at the label rate. From first flowers, give liquid potash at the label rate, fortnightly.
• Position: full sun in spring; in hot districts, move the pot into afternoon shade for summer.
• Repotting: every few years in spring, move the bush into a larger pot of fresh mix.

Planting Canes

Black currants start from a dormant bare-root cane planted straight into prepared ground or a large pot. Red currant, which covers the white currant, has its own guide because it is pruned differently, and the raspberry guide uses the same bare-root handling.

Bare-root preparation

The cane arrives leafless, with bare roots and a short woody stem. Never let the roots dry out, and plant as soon as you can. If the bed is not ready, heel the cane into a shallow hole in a cool spot and keep it watered. Soak the roots for one to two hours in a bucket of water with seaweed solution at 30 mL per 9 L. Soaking much longer than two hours can rot them.

Planting in the ground

• Dig a hole at least twice as wide as the spread of the roots.
• Set the cane about 5 cm deeper than it grew before, judged by the soil mark on the stem. New shoots then rise from below ground.
• Spread the roots, backfill, firm the soil to remove air pockets and water in thoroughly.
• Cut the stem back to 5 to 7 cm above the soil, just above an outward-facing bud.
• Mulch with compost or well-rotted manure, leaving a small clear circle around the stem.

The hard cut means no fruit in the first summer. It makes the plant send up several strong shoots from the base, and those carry the first crop the summer after.

State weed and biosecurity lists

Outside Western Australia, which keeps its own organism list, no state or territory lists black currant or any other Ribes as a declared weed. Tasmania and Western Australia also control plants brought in from other states.

Lists change, so check your state or territory's current list before planting.

Care by growth stage

Steady moisture and plenty of nitrogen in spring decide the crop, with potassium from flowering.

Top up the mulch each spring, keeping it clear of the stems, to hold moisture and keep the roots cool.

Pruning and Training

Black currants fruit best on young wood, mostly the pale stems that grew the summer before. Pruning replaces old stems with new ones from the base each year. Prune while the bush is dormant in winter, or start once fruiting ends in late summer or early autumn.

• First three years: the cut at planting is the main pruning; after that, remove only weak or low-lying shoots.
• Old wood: from about the fourth winter, cut the oldest, darkest stems at ground level each year, a third of the bush or more. They crop less and need loppers.
• Young wood: leave pale, one-year-old stems at full length, since they carry next summer's fruit.
• Shape: remove dead, diseased, crossing and low stems, cutting to an outward-facing bud to keep an open goblet shape.
• Centre: rub off buds and shoots pointing into the middle of the bush.
• Stem count: aim for about 6 to 10 strong stems.

A weak bush needs a harder cut: take at least half its stems to the base to push up strong new growth.

Companion planting

A black currant stays put for years, so companions work best as low flowers around its base.

Grows well with

• Marigold, often planted with currants, which draws beneficial insects.
• Alyssum, whose small flowers draw beneficial insects.

Keep apart

• Red currant, white currant and gooseberry, close relatives that host the same currant borer moth.
• Potato and other crops dug each year, which disturb a shrub that needs settled ground.

Harvesting Fruit

Pick from about December to January, once the berries have turned fully black and glossy.

• Berries at the top of each bunch, called a strig, often ripen first, so pick them singly as they colour.
• Where a whole strig ripens together, cut it off and strip the berries in the kitchen.
• Handle them gently, as ripe currants squash easily and the juice stains.

Fresh currants keep for a few days in the fridge, and freeze well raw or cooked. The tart fruit is mostly cooked or sweetened, into jam, jelly, cordial, syrup and pies.

Common problems

No fruit in the first summer. This is expected after the hard cut at planting; see Planting Canes.

Plenty of leaves but few flowers. The winter was too mild for the fruit buds; see Three mistakes that matter and the zone notes under When to plant.

Flowers drop soon after a cold night. Frost killed the open flowers; cover the bush at flowering as When to plant describes.

Split berries. A heavy soaking as fruit ripens swells and splits the skins; keep watering even, as Care by growth stage shows.

Leaf edges turning brown. Summer heat and hot, dry wind can scorch leaf edges, so shelter the bush and water deeply. Otherwise, browning can signal a shortage of potassium, which the sulphate of potash in the flowering row of Care by growth stage supplies.

Fruit gone before you pick it. Birds and possums take ripe currants quickly; net the bush as Three mistakes that matter describes. Read more

Pests and diseases

Black currants are usually healthy, and most trouble comes from a few insects and damp weather.

Currant borer moth (Synanthedon tipuliformis). An introduced clearwing moth found in the ACT, New South Wales, South Australia, Tasmania and Victoria. Its larvae tunnel through the pith of black currant, red currant and gooseberry stems. Shoots wilt and die back, and a cut stem shows a tunnel in its centre. Cut affected stems off at ground level in winter and bin them, never compost them.

Two-spotted mite (Tetranychus urticae). Tiny mites feed under the leaves, leaving yellow stippling near the main veins, and numbers climb fast in hot, dry weather. Predatory mites and ladybirds usually keep them down, so avoid needless sprays. Read more

Aphids, including currant lettuce aphid (Nasonovia ribisnigri). Colonies cluster on soft shoot tips in spring and curl the young leaves. Hose them off or spray insecticidal soap, and leave the ladybirds and hoverflies that eat them. Read more

Grey mould (Botrytis cinerea). Grey fur covers flowers and rotting fruit, spreading most in cool, damp weather. Pick off affected flowers and fruit, water at soil level, and keep the bush open.

Prevention first

• Start with a healthy cane from a reliable supplier, and take cuttings only from vigorous, healthy bushes.
• Prune every winter to keep the bush open, cutting out weak, dying or hollow stems at the base.
• Water at soil level in the morning, and keep mulch clear of the stems.
• If a spray is needed, choose one registered for the pest and crop, and follow the label and its withholding period. Pyrethrum harms bees, so spray late in the day away from open flowers.

Tips

1. Take hardwood cuttings in winter from healthy young stems. Cut pencil-thick lengths of 15 to 20 cm just below a bud, and rub off the lower buds. They often root within two months.
2. Set the cuttings in pots in a sheltered spot, or straight into deep, well-drained soil in a protected position. Leaf buds opening in spring show they have rooted.
3. If you grow several currants and gooseberries, a walk-in fruit cage covers them all and makes netting a one-off job.

Due to quarantine restrictions and our shipping policy, we cannot send black currant canes to Western Australia or Tasmania.