How to grow blackberries — thornless varieties + pruning

How to grow blackberries — thornless varieties + pruning

Modern thornless blackberries are nothing like the wild brambles your grandfather fought with secateurs and a bandaged forearm. The new generation crops heavily, grows in a manageable footprint, and harvests without drawing blood. They are the natural companion crop to home-grown raspberries — the same cane-fruit family, the same trellis hardware — and pair well in a soft-fruit bed with blueberries and strawberries. The trade-off is they want a proper trellis and a pruning routine that depends on cultivar type. This guide explains how to pick the right one, build the support, and prune it the right way.

Track your blackberry canes: Add your cultivar to Growli and the app tracks pruning, training, and harvest windows based on whether the variety is floricane- or primocane-fruiting.

Three habits — pick yours first

Blackberry cultivars fall into three growth habits, and each one wants a different trellis:

• Erect — self-supporting upright canes, 1.5-2 m (5-7 ft) tall. Easiest in small gardens; need minimal support. Examples: Apache, Navaho, Ouachita.
• Semi-erect — vigorous canes that arch and need a wire trellis. The most productive group. Examples: Triple Crown, Chester, Loch Ness.
• Trailing — long flexible canes that grow horizontally; need full T-trellis or fence. Examples: Marion, Oregon Thornless, Boysenberry. Most popular in the US Pacific Northwest.

If you're new and have limited space, start with an erect thornless cultivar like Apache or Navaho. The trellising is simpler and the canes don't sprawl into other beds.

Variety selection

US thornless varieties

• Apache — University of Arkansas-bred, erect habit, very large fruit, ripens mid-season. Self-supporting, winter-hardy through USDA zones 5-9, resistant to orange rust.
• Triple Crown — semi-erect, USDA zones 5-9, large sweet aromatic berries, the most productive home-garden choice in the US East. Vigorous canes need wire support.
• Navaho — Arkansas-bred erect thornless, sweet small-medium fruit, USDA zones 5-9. Less vigorous than Triple Crown.
• Natchez — early-ripening thornless, large elongated berries, sweet-tart flavour, USDA zones 5-9. PVP (Plant Variety Protected) — buy from licensed nurseries.
• Prime-Ark Freedom — primocane-fruiting thornless variety from Arkansas. Fruits in the first year on this year's canes.

UK thornless varieties

• Loch Ness — the standard UK garden blackberry. Semi-erect, thornless, heavy yields of large glossy berries, excellent flavour. Bred at the James Hutton Institute in Scotland.
• Oregon Thornless (sometimes "Thornless Oregon" or "Oregon Cutleaf") — trailing, attractive parsley-cut leaves, vigorous, late-ripening, very hardy.
• Helen — early-ripening thornless, compact for a blackberry, suits smaller gardens.
• Loch Maree — newer thornless cultivar with double-pink flowers — productive AND ornamental.

Floricane vs primocane

Like raspberries, blackberries split into two pruning groups:

Floricane-fruiting (most cultivars)

Fruit forms on last year's canes. Standard pattern:

• Year 1: cane grows tall and bushy (primocane).
• Year 2: same cane (now a floricane) flowers and fruits, then dies.
• After fruiting: cut floricanes to the ground; train this year's new primocanes for next year.

All the classic varieties — Apache, Triple Crown, Navaho, Loch Ness, Oregon Thornless — are floricane.

Primocane-fruiting (newer)

Fruit forms on this year's canes, like autumn raspberries. Cut everything to the ground each winter. Examples: Prime-Ark Freedom, Prime-Ark Traveler.

Primocane blackberries crop later in summer and into autumn, but the first-year cane crop is smaller than a mature floricane plant's. They're easier to prune (one cut to the ground), which is why they're worth considering for beginners.

Soil and site

Blackberries want:

• Full sun — 6+ hours minimum; 8 hours best.
• Well-drained soil — they tolerate heavier soil than raspberries but still hate waterlogging.
• Slightly acidic pH — 5.5-6.5 ideal. Test with our soil pH guide.
• Plenty of organic matter — dig in 5-7 cm (2-3 inches) of compost before planting.
• Shelter from strong wind — long canes break easily.

Avoid replanting where blackberries, raspberries, potatoes, tomatoes, peppers, or aubergines have grown in the last 3-4 years.

When and how to plant

When

• Bare-root plants: plant in dormancy — November to March in the UK, late autumn or early spring in the US after the ground thaws.
• Container-grown plants: any frost-free month; spring is best.

Use the frost-date calculator to pick your local window.

How

1. Dig a hole 30-45 cm (12-18 inches) wide and deep.
2. Mix compost into the backfill.
3. Set the crown at the same level it grew at the nursery — look for the dark soil mark on the stem.
4. Space by habit:
   • Erect varieties: 1.0-1.2 m (3-4 ft) apart in row
   • Semi-erect varieties: 1.8-2.5 m (6-8 ft) apart in row
   • Trailing varieties: 2.5-3 m (8-10 ft) apart in row
   • Row spacing 2.5-3 m (8-10 ft) between rows
5. Cut canes back to 15 cm (6 inches) after planting. Forces strong basal growth.
6. Mulch with 5-7 cm of compost or bark.
7. Water in well.

The T-trellis

For semi-erect and trailing varieties, build a T-trellis:

1. Set 2.4 m (8 ft) treated wooden posts every 3-4 m (10-13 ft) along the row, driven 60 cm (24 inches) into the ground.
2. Attach a 0.6 m (2 ft) cross-bar at the top of each post, forming a T.
3. Run two horizontal wires at the ends of each cross-bar — one each side of the row, at the top (1.8 m / 6 ft) and a second pair at 1.0 m (3 ft).
4. As primocanes grow, train them along the lower wires on one side. Train fruiting floricanes along the upper wires on the opposite side. The split keeps the two-year cycle visually obvious and makes pruning trivial.

Erect varieties get away with a simpler two-wire fence at 1.0 m and 1.5 m heights, with no cross-bar.

Watering and feeding

Watering

• 2.5-4 cm (1-1.5 inches) per week during the growing season, more during fruit-fill.
• Drip or soaker hose at the base — avoid wetting foliage and ripening fruit (fungal disease).
• Mulch deeply (5-7 cm of bark or compost) and keep it topped up each spring.

Feeding

• Mulch annually in late winter with composted manure or garden compost.
• Top up with sulphate of potash in early spring.
• Foliar seaweed feed every 3-4 weeks during fruit development for the cleanest flavour.
• Avoid high-nitrogen feeds — they push soft growth and reduce winter hardiness.

Pruning — by type

Floricane varieties

Summer (right after fruiting, July-August):

• Cut the fruited canes (floricanes) right to the ground.
• Identify them by the dried-up fruiting laterals and the darker, more woody bark.
• Keep this year's new green canes (primocanes) for next year's crop.

Late winter (February):

• Tip-prune primocane laterals to 30-45 cm (12-18 inches) — this concentrates fruiting.
• Thin to 4-6 strong canes per plant (erect) or 6-8 per metre of row (semi-erect).
• Remove any winter-damaged tips.

Primocane varieties

In late winter, cut every cane to the ground. New canes emerge in spring, fruit in late summer / autumn. No mid-year pruning needed.

Pests and problems

• Spotted wing drosophila (SWD) — major US and UK pest of soft fruit. Lays eggs in ripening berries; larvae hatch inside. Pick fruit promptly; refrigerate immediately; bin damaged fruit. Use 1 mm exclusion netting during fruiting.
• Raspberry / blackberry cane borer — wilted shoot tips with two rings of holes around the stem. Cut affected canes back below the lowest puncture and bin (do not compost).
• Anthracnose — purple lesions on canes and leaves. Improve airflow, avoid overhead watering, use resistant varieties (Triple Crown, Apache).
• Orange rust — bright orange pustules on undersides of leaves. Systemic — there's no cure. Dig up and destroy affected plants. Choose resistant cultivars from the start.
• Birds — net the plants from when berries start to colour. Use 5 mm or smaller mesh to avoid trapping wildlife.

For broader pest ID, see our garden pest identification hub.

Harvesting

A ripe blackberry pulls off the receptacle (white core) cleanly with a gentle tug. Unlike raspberries, blackberries keep their core attached to the fruit — if the receptacle stays on the plant when you pick, you're 1-2 days too early.

Pick every 2-3 days during the peak. Berries deepen from red to glossy black to dull black; the dull-black stage is fully ripe and sweetest.

Yields:

• Year 2: 1-3 kg per plant (2-7 lb)
• Mature plant: 4-7 kg per plant (9-15 lb)

Blackberries don't ripen after picking. Eat within 2 days, freeze on a tray for storage, or make jam, cobbler, or syrup the same day.

How long a blackberry patch lasts

A well-tended blackberry row stays productive for 15-20 years with annual pruning. Replace plants if yields halve or virus pressure builds. Don't replant blackberries in the same ground without a 3-4 year break in another crop.

Related articles

• How to grow raspberries — sibling cane fruit
• How to grow blueberries — sibling acid-soil berry
• How to grow strawberries — sibling soft fruit
• Frost-date calculator — your local windows
• Soil pH guide — target 5.5-6.5 for blackberries
• Garden pest identification — diagnosing cane issues
• Companion planting guide — what to plant near soft fruit

Reviewed and updated by the Growli editorial team. Founded by Justas Macys and Nojus Balčiūnas; published by YNMO LTD (UK Companies House #13293288). For questions about anything here, open Growli and ask — or email hello@getgrowli.app.