Blackberries are vigorous and exceptionally spiny, hardy perennial cane fruits belonging to the genus Rubus. The species and hybrids listed below are grown for dessert, bottling, tarts, jam and wine.
Blackberries prefer deep, moist and rich loam but are adaptable to light sands and stiff clays, given free drainage and freedom from perennial weeds. Incorporate bulky organics such as farmyard manure, compost, shoddy, and feed with fish- or meat-meal and sulphate of potash. Correct iron deficiency on soils containing free lime by dressings of chelated iron.
Planting sites subject to frost are suit-able as flowering is late, in early July. Provide shelter from strong winds for the brittle laterals and tie them into training wires.
Plant first-year plants, shortened to 9 inches in the autumn at up to 12 feet apart, against walls or fences or posts and wires. Train the young replace-ment shoots of established plants to one side of, or above, the fruiting canes to prevent contamination with fungus dis-eases. Cut out fruited shoots after harvest.
- Propagate by tip layering in June or July, by leaf bud cuttings in August, or by rooted suckers in the autumn (see Propagation).
- Control greenfly, capsid bug, raspberry beetle and cane spot and destroy plants infected with crown gall or stunt virus (see Crown gall and Virus diseases).
- Avoid deep cultivation which is liable to damage shallow roots.
- Blackberry and loganberry fruiting takes place mainly on young shoots which grew in the previous year. A few varieties, e.g. ‘John Innes Berry’ form fruits on two-year-old shoots.
- Young plants are pruned to 3-4 buds after planting, and the strong shoots that grow are tied to suitable supports to fruit the year after. In the following years new shoots will grow on old wood and also come from ground level. After fruiting, cut out as much of the old wood as possible and train in the new shoots. If there are too many, remove the surplus completely. With the weaker growing loganberries, 6-8 new canes each year should cover the framework. Shoots growing above the framework can be arched over and if need be, pruned in spring.
- These fruits can be trained as fans, spread over the framework. New canes are looped along the lowest wire as they grow and then in autumn take the place of the old.