Step-by-step guide to growing Blackberries
Species of Rubus (fam. Rosaceae) mainly derived from R. fruticosus, which itself has been subdivided into many species.
Hardy perennial cane, usually prickly, with a cropping life of about 15 years.
Planting to harvesting time: two years Size: 1.8 m (6’) in height and up to 4.5 m (15’) wide when trained.
Yield: about 2.25-4.5 kg (5-10 lb) per plant.
Shiny sweet and flavourful, blackberries are among the easiest of cane fruits to grow. They will thrive in almost any, and will produce good crops even when grown in heavy shade. Because they flower late, and over a long period, frost does not bother them at all; even if some flowers are killed by late frosts, more will be produced. Although birds may take the occasional berry, they are not generally troublesome and there is no need for blackberries to be grown in a fruit cage.
Blackberries used to have a reputation for being awkward and difficult garden plants because of their over-vigorous growth, which quickly swamped neighbouring fruits and vegetables. Also, annual pruning, which is necessary if the plants are to crop at all well, was regarded as a formidable, and often painful, task because of the numerous wicked thorns which cover the canes. Luckily, plant breeders have solved both of these problems. There are several new varieties with moderate growth habits available and these are eminently suitable for. Secondly, thornless varieties have been developed which make pruning easier.
Blackberries have not been widely cultivated because, in suburban and rural areas, bramble hedgerows were so abundant and, in good years, the fruit plentiful. However, there are far fewer hedgerows today than in the past, due to intensive farming methods and increased pressure on land generally. Some people still prefer the slightly acid taste of the wild blackberry, but cultivated varieties tend to have larger berries and heavier crops.
Suitable site and soil
Blackberries are very accommodating with regard to site and soil; indeed, they can often be grown in dark corners where nothing else will grow. However, if you want first class crops, then some care must be taken in selecting a site and preparing the soil. Unlike strawberries, replaced every three years or so, blackberries can have a useful life of ten to fifteen years or more, making initial choice of site particularly important.
It should be reasonably sheltered from north and east winds and, although the blackberry is a shade-tolerant plant, crops will be heavier if full sun is available. Low-lying land, or land subject to frost is no problem, because blackberries flower very late in spring or perhaps early summer and even a late frost will do little harm. Flowers will continue to appear right through the summer, even if earlier ones are killed.
Well-drained medium to heavy loams are ideal; light or sandy soils need additionaldug in. Whatever the soil type, it must be moisture retentive; if the plants run short of water in summer, hard, small berries will result. A chalky soil is least suitable, and if you want to attempt blackberries on chalky soil, then plenty of manure must be dug in before planting. Depending on the quality of the existing soil, add between 2.5 and 6.5 kg per sq m (5 and 15 lb per sq yd). Ideally, the soil should be slightly acid, with a pH of 6.5-6.8. As a general rule, thorny varieties of blackberries are stronger than thornless ones. If your soil is not first class, or the only spot left in your garden is a shady one, select a strong-growing variety like be very heavy, and if you skimp on your support system, you may find that a bad storm will cause plants, posts and wires to collapse.
Use 3 mm plastic coated wires, or else insulated telephone wire. Alternatively, agricultural pig fencing can be used. The wires should be 30 cm (1’) apart, starting 90 m (3’) above the ground. Try to attach the wire ends to straining eyes, so that any subsequent sagging can be easily corrected. Intermediate struts between the main posts will help in this respect, too. The end posts should be propped with additional struts, or you can run guy ropes from the top of the post outward to a well-secured peg.
On a wall, fence or shed, the same spacing between wires should be used. Secure the wires by fixing them to vine eyes which have been hammered into the brick or wood.