How Blackberries Are Cultivated

Selecting a Cultivar

• There are three main types of blackberries -- trailing, erect and semierect. Trailing blackberries produce high-quality, flavorful fruit on vigorous trailing vines. These plants are generally trained to a trellis. Trailing blackberries are the least cold-hardy of all varieties, sustaining damage when temperatures drop below 20 degrees F in the fall and early winter. Erect and semierect blackberries grow on stiff canes. These plants produce fruit later than trailing blackberries, but may continue to yield harvests until the first frost. The fruit of semierect and erect blackberries is larger and milder in taste. Consult a local county extension office or nursery specialist when purchasing blackberries. Recently improved varieties are more cold-hardy, an important consideration if you live north of zone 6.

Planting Blackberries

• Blackberries are perennial plants and may live for 15 to 20 years if properly cared for. Choose a sunny location close to a water source, and amend the soil with organic matter, such as manure or compost. Add lime if the soil pH is lower than 5.5. Consider using raised beds if your soil drains poorly, such as a heavy, clay soil. Buy certified disease-free bare root or potted blackberries from a nursery. Plant the blackberries in early spring when the soil is soft, digging a hole large enough to spread out the roots. Plant bare root plants with their crown 1 to 1 1/2 inches below the soil.

Pruning and Trellising Blackberries

• All blackberry types benefit from a trellis. A trellis supports the weight of the vines, protects them from wind damage and simplifies pruning and harvesting tasks. Several types of trellises work, such as a single trellis with wires stretched between two poles, or a V-trellis that utilizes wires strung between four poles.

  Blackberries are biennial. They produce woody growths known as primocanes the first year. The second year these canes produce fruit after which they die (floricanes). Prune trailing blackberry primocanes in early fall, training them to a trellis. Remove floricanes in late winter.

  Cut the tips back of newly emerging primocanes from erect and semierect blackberries when the canes stand 4 feet high. This will encourage growth and increased fruiting the following summer. Cut down to the ground any suckers that grow outside the trellis. Cut dead floricanes back to the ground in December or January.

General Care

• Blackberries, like any fruiting plant, need a lot of water to produce goo-quality fruit. Water them as you would a vegetable garden, providing 1 to 1 1/2 inches of water each week during the growing season. Drip systems conserve water and minimize diseases due to wet leaves.

  Hand pull weeds in the blackberry patch or cultivate them shallowly with a hoe. Weeds compete with the blackberries for nutrients and water, reducing the quality of the fruit. Apply a 2- to 3-inch layer of wood chips, straw or untreated grass clippings to the patch to reduce weed growth.

  Fertilize newly planted blackberries with 25 lbs. of 10-10-10 granular fertilizer after planting and four to six weeks later. Apply 20 lbs. of 10-10-10 fertilizer annually in the spring thereafter, dividing the application as previously directed.