How to grow Blackberry in Australia

Where to plant

Plant in a sunny, sheltered spot in fertile, well-drained soil with compost dug in. Blackberries need a winter rest and do best in cool and temperate climates. Set up the trellis before planting: a strong post at each end of the row with two or three wires.

Wild blackberry (Rubus fruticosus aggregate) is a Weed of National Significance and is declared in every state and territory. Selling, swapping or moving it is restricted, and in the ACT it is a prohibited pest plant. Named thornless cultivars that do not spread by seed in the same way are exempt from most of these rules, but the permitted list differs by state, so check before you buy. Never dig up and transplant wild canes.

• NSW and the ACT: permitted cultivars include Black Satin, Chehalem, Chester Thornless, Dirksen Thornless, Loch Ness, Murrindindi, Silvan, Smoothstem and Thornfree.
• South Australia: only six named thornless cultivars may be sold: Black Satin, Dirksen Thornless, Smoothstem, Thornfree, Loch Ness and Chester Thornless.
• Victoria and Tasmania: wild blackberry is declared and landowners must control it; named thornless commercial varieties are not covered by the Tasmanian declaration.
• Hobart, Melbourne, Canberra and Adelaide suit blackberries well. Sydney, Perth, South East Queensland and the Northern Rivers have milder winters, so choose a variety suited to warmer areas.
• North Queensland and Darwin: not suitable, as cane berries need a winter dormancy.

Choosing a variety

• Chester Thornless is a widely grown, late-ripening thornless variety.
• Other permitted thornless types include Black Satin, Dirksen Thornless, Loch Ness, Smoothstem and Thornfree. Waldo is another thornless variety sold in some states.
• Thornless canes are much easier to train, prune and pick than thorny types.

How to plant

1. Put in the posts and wires first. Wires about 45 cm apart, with the lowest about 45 cm above the ground, suit most varieties.
2. Dig compost into the row and plant the bare rooted canes in winter, about 1.5 to 3 m apart depending on the variety's vigour.
3. Spread the roots, plant at the same depth as before, water in and mulch.
4. Cut the cane back to a bud about 20 to 30 cm above the ground to encourage strong new shoots, then tie the new canes along the wires as they grow.

Watering and feeding

Water deeply during dry spells, especially while the berries are forming and swelling. Mulch thickly to keep the roots cool and moist, and water at the base rather than over the fruit.

Plants in well-mulched soil need little extra feeding. Give a balanced fertiliser or compost in early spring as growth starts if crops decline.

Pruning and care through the year

• Blackberries fruit on canes grown the previous year. Once a cane has fruited it will not fruit again.
• Straight after harvest, cut the fruited canes off at ground level. They are easy to spot by the old fruit stalks and brittle wood.
• Train new canes one way along the wires, or bundle them in the centre, keeping them apart from the fruiting canes, so you always know which to remove next.
• Do not let cane tips touch the ground. Blackberry tips root where they land, which is how the plants spread.
• Net the plants against birds as the fruit colours.

Harvesting

Berries ripen from about December to February. Pick them when they are fully black, glossy and come away easily, as they do not ripen further after picking. Pick every couple of days in the main season, preferably in the cool of the morning.

Blackberries are soft and keep only a day or two in the fridge. Freeze surplus berries spread on a tray, or make jam.

Growing in pots

Only compact varieties suit a pot. Use one at least 45 cm wide and deep with a quality potting mix and a small trellis, and water regularly, as pots dry out quickly.