How to grow Blackcurrant in New Zealand

Where to plant

Blackcurrants are best in cool to cold climates and moist conditions. Give them morning sun with protection from hot afternoon sun, in moist, well-drained soil enriched with organic matter, similar to what suits blueberries. A cool spot on the south side of the garden, or in the light shade of trees, works well. They can be grown as a free-standing bush or as a low hedge.

• Waikato and Bay of Plenty, the central North Island, Wellington, Nelson and Marlborough, Canterbury, Otago and Southland, and Central Otago: blackcurrants do very well. Plant from June to August.
• Auckland: views differ. Yates says Auckland winters are too mild, while Incredible Edibles says Auckland gives enough chill. Try a lower-chill variety such as Sefton in a cool, sheltered spot.
• Northland: our calendar marks it as unsuitable, as the winters are too mild to give the chill blackcurrants need to fruit.

Choosing a variety

• Magnus: extremely hardy and upright, with large black fruit high in vitamin C, ripening from late December to February. Tart, but sweeter when fully ripe.
• Ben Mapua: very heavy yielding, with very large fruit about two weeks after Magnus, in February. Large, vigorous and spreading.
• Sefton: large, sweet berries from late December to early February, and needs less winter chill than Magnus.

How to plant

1. Dig in plenty of compost or organic matter.
2. Plant bare-root bushes in winter, spreading the roots and backfilling gently. Space bushes at least 1.5 m apart.
3. Form a ring of soil around the root zone to hold water, and water in well.
4. Keep the soil moist for several weeks while the plant settles, and mulch, keeping it clear of the stems.
5. After planting, cut young bushes back to two buds above the ground to encourage strong new stems from the base.

Watering and feeding

Keep the soil moist, especially in spring and while the fruit fills out. Mulch every spring. Potted bushes need a deep watering every two or three days, and more often in warm weather.

An annual spring feed with a citrus or fruit fertiliser is all blackcurrants need.

Pruning and care through the year

• Blackcurrants fruit on wood that grew the previous season, so pruning is about keeping a supply of young stems.
• After the first cut-back at planting, leave the bush unpruned for two seasons.
• From then on, prune in winter while dormant: remove about a third of the oldest stems each year, cutting them to a low bud or to the ground, so no stem stays more than about three years.
• Also remove dead, diseased, crossing and low, sprawling growth.
• Grow under netting or in a fruit cage, as birds take the ripe berries.

Harvesting

Blackcurrants ripen in December and January, and later varieties into February. Pick when the berries have turned shiny dark purple to black.

Fresh berries keep only a few days in the fridge but freeze brilliantly in a sealed freezer bag.

Growing in pots

A blackcurrant grows well in a pot at least 40 cm wide in quality potting mix, in a spot with morning sun and afternoon shade. Water deeply every two or three days, more in hot weather, and feed in spring.

Using it

Use blackcurrants for cordial, jam, jelly, pies, muffins and tarts, or sprinkle them on muesli and porridge. They are also used to flavour liqueurs.

Propagation and saving seed

Blackcurrants are sold as rooted cuttings or bare-root plants in winter, and once planted and well treated they last for many years.