Bramble fruits are very easy to grow. The keys to good yields are adequate spacing and light, and, because of shallow roots, good weed control and thick mulch. Rather than several short, close rows that limit berry development to only the upper cane parts, plant one long, narrow row that will produce berries to the bottom of the canes.
Blackberries are biennial. First-year green stems, primocanes, bear only leaves. Two-year old brown stems, floricanes, produce fruit. Upright or erect canes are shorter, while trailing varieties (also known as dewberries in the South), grow flexible canes as long as 10 ft. Blackberries are usually hardy to zones 5-8; upright varieties are the hardiest.
When berries slide off easily without pressure, harvest into very small containers so berries on the bottom won't be crushed. After harvest, cut back floricanes to the ground. For disease control, burn or dispose of all cut canes.
Freeze within 2 days by spreading berries on cookie sheets and freezing. When rock hard, store in heavy freezer bags. Refrigerated, they keep 4-7 days.
Height - 4-10 ft. when pruned
Spacing - Erect and Semierect Blackberry: 2-3 ft. in a row (suckers and new canes fill out row). Trailing Blackberry: 6-12 ft. in a row (no suckers, but canes grow very long).
Root Depth - More than 12 in.
pH - 6.0-6.5
Bearing Age - 2 years
Pollination - self-pollinating.
Chilling Requirements - Hours needed depending on the variety.
Site - Full sun; rich loam. Due to verticillium wilt, avoid planting where nightshade family plants were grown in the last 3 years. Plant at least 300 feet away from wild brambles (which harbor pests and diseases) and from raspberries to prevent cross-pollination.
Water - Medium; Drip irrigation is essential to avoid weater on the berries, which is absorbed and dilutes falvor. Water regularly because of vulnerability to water stress.
Mulch - In summer, apply 4-8 in. of organic mulch; in winter apply 4-6 in. of compost.
Fertilizer - In spring, apply well-rotted manure or compost before canes break dormancy.
Training - A trellis is very inmportant for disease and pest reduction, quality fruit and easy harvest. For erect blackberries use a 4 ft. top wire; for trailing blackberries use a 5 ft. top wire. Fan out canes and tie with cloth strips.
Pruning - After harvest or in spring, cut out old canes done bearing. Erect blackberries, thin to 5-6 canes per row-foot; to encourage branching, cut off the top 3-4 in. when primocanes are 33-40 in.; late the following winter, cut the lateral branches back to 8-12 in. long. Trailing blackberries, thin to 10-14 canes per hill; don't prune in the first year; in late winter cut canes bakc to 10 ft.
Pests & Diseases
caneborer, mite, raspberry root borer, strawberry weevil, whitefly, white grub.
Anthracnose, botrytis fruit rot, cane blight, gall, crown gall, powdery mildew, rust, septoria leaf spot, verticillium wilt.