General
Blackberry is a vigorous bramble producing sweet, dark berries on second-year canes (floricanes). Many modern cultivars are thornless and semi-erect, making training and harvest easier. In colder parts of Sweden choose very hardy cultivars and consider winter protection by bending and securing canes low. Plants spread via primocanes and can tip-root; use barriers or regular pruning to keep them contained. Good airflow and sun reduce disease pressure and improve sweetness.
Light
Full sun for best yield; tolerates light partial shade in warm sites.
Soil type
Moist, fertile, well-drained loam enriched with organic matter; slightly acidic is ideal.
Water requirement
Moderate to high during flowering and fruit filling; keep evenly moist but not waterlogged.
Nutrient requirement
Moderate feeder; annual compost plus light nitrogen in spring and a balanced feed early summer.
Precultivation
Blackberries are normally propagated vegetatively (tip layering, cane cuttings, or buying potted plants). Seed is slow and variable, requiring stratification; use only for breeding. For cuttings, take 10–15 cm softwood cuttings late spring or root primocane tips in small pots. Maintain gentle bottom heat (18–22°C) and high humidity until rooted.
Planting
Plant container-grown shrubs in spring once the ground is workable and frost risk is low (soil ≥8–10°C). Space 2–3 m between plants and 2.5–3 m between rows. Plant at the same depth as in the pot, water in well, and mulch 5–8 cm with composted bark or straw, keeping mulch off the crown. Install a support: for semi-erect types use a two- or three-wire trellis (wires at ~60/120/180 cm). Train new primocanes vertically and tie fruiting canes laterally.
Pruning
Blackberries fruit on last year’s canes (floricanes). After harvest, remove spent floricanes at ground level. In late winter, thin primocanes to 5–7 of the strongest per plant and head them to encourage laterals (for erect types). Summer pinch primocanes at 1.8–2.0 m to limit height. Remove weak, diseased, or crossing canes anytime. Keep the crown open for airflow.
Maintenance
Maintain consistent moisture—about 25–40 mm/week in dry spells. Mulch annually to suppress weeds and stabilize soil moisture. Feed in early spring with compost plus a light nitrogen source (e.g., pelletized poultry manure), then a balanced organic feed as flower buds form. Monitor for cane diseases; ensure good trellis training and avoid wounding wet canes. Net plants before ripening to deter birds. In cold zones, lay canes along the lower wire in late autumn and cover lightly with spruce boughs or breathable fleece.
Harvest
Berries ripen from early August into late September depending on cultivar and site. Begin with an early flush mid-August, followed by a second flush into September. Pick when fully black with a dull sheen and they release with a gentle tug; underripe fruit tastes tart. In warm spells harvest daily; otherwise every 2–3 days. Late-season fruit can be sweeter after sunny days but is more prone to mold—pick promptly in wet weather. Handle in shallow trays and chill immediately; don’t wash until use. Keeps 2–4 days refrigerated or freeze promptly.
Common issues
Cane blight and spur blight: prune out infected canes, disinfect tools, and improve airflow. Botrytis on fruit: avoid overhead irrigation and harvest promptly. Mites and aphids: encourage beneficials, use targeted soap sprays if needed. Winter dieback: choose hardy cultivars, avoid late nitrogen, and protect canes in exposed sites. Iron chlorosis on high-pH soils: acidify with elemental sulfur and use composted conifer bark mulches.
Pollination
Self-fertile, though cross-pollination from another cultivar can improve set and size.
Companion plants
Strawberries, borage, chives, comfrey, calendula, clover understory for living mulch.
Incompatible plants
Avoid close proximity to raspberries and other Rubus if virus or cane blight pressure is high; avoid walnut drip line.
