A healthy and well-maintained plant easily survives the winter and produces high, consistent yields. To increase fruiting at the end of the season, a series of measures are taken to improve growing conditions, including pruning branches, staking, and covering the plant for the winter. Properly pruned blackberries in the fall will help the bush develop more quickly in the spring, become lush over the summer, produce strong young shoots, and produce large berries.
Why is autumn pruning necessary?
Blackberries are a plant with a two-year fruiting cycle. In the first year, the plant develops and forms strong shoots. The emerging buds are pruned to prevent them from drawing nutrients from the stems.
In the second season, the branches become woody, flower buds appear, and the subshrub produces a harvest of sweet black berries. To stimulate flowering the following summer, the blackberry should be pruned for the winter. Otherwise, the fruit will not set in the third year.
Trimming promotes plant rejuvenation and active shoot formationPinching the top of the plant in the first year stimulates the growth of lateral shoots. Removing old branches and dry tips allows young shoots to mature and strengthen faster. Last year's stems should not be left, even if they are lush and strong. They will impede normal air circulation, resulting in weakening of the bush, and the development of mold and rot. Such a plant may die before spring or take a long time to recover from winter.
Pruning is also used to thin out overly dense bushes. All blackberry varieties are sun-loving and do not tolerate light shade. Excessive bushiness prevents sunlight from reaching the center of the plant, complicating harvesting. In the summer, with insufficient light, the berries grow sour and small, and young branches slow in growth and do not have time to ripen. In the fall, long stems are more difficult to protect from the cold, making bushy subshrubs less frost-resistant.
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Deadlines for completion of work
Pruning blackberries in the fall is a rather labor-intensive process for novice gardeners, as shaping the bush requires dividing the branches into age-specific sections (annual and biennial), and the presence of thorns complicates the task. Pruning and positioning the vines can take several days.
Autumn pruning is performed from August 30 to the end of OctoberInexperienced gardeners are better off starting to prune the shoots immediately after fruiting. It's important to finish the work a month before the onset of frost, so that pre-winter feeding can be carried out. Sufficient sunlight will help the plant recover, accumulate nutrients, and grow stronger.
Tools for processing bushes
For this work, you'll need loppers and pruning shears. If the diameter of the woody shoots exceeds 1.5 cm, use a pruning saw.
Pruning blackberry bushes with a clean and sharp toolSharp blades make the process easier and faster. The saw's specially sharpened teeth and set angle allow for bidirectional cutting. The tool leaves behind smooth, even edges for a neater appearance. This process reduces the risk of infestation.
For stems less than 1.5 cm thick, use pruning shears. The tool should not break, chew, or split the twigs, or leave uneven cuts. If this occurs, choose a tool with a minimal gap between the blades. For thorny shrubs, anvil-style pruning shears are suitable. When pruning, always hold the tool at the same angle to avoid breaking the stem.
Formation and placement of whips
There are blackberry bushes with trailing and upright stems, thornless varieties, and varieties with numerous straight or curved thorns. As the berry bushes grow and develop, young shoots are tied to supports. Blackberry bushes should not be allowed to grow freely.
Without support, long young and old stems become intertwined, complicating shaping the bush. On trailing varieties that grow on the ground, the vines will quickly root, and the berries will rot. Using a special trellis makes pruning and harvesting easier.
There are two methods of bush formation:
- The fan (vertical) method is used for upright varieties. The plant stems are secured to a fan-shaped support. Last year's branches are tied vertically, while new shoots are positioned horizontally along the sides. After harvesting, the fan's ribs are trimmed above ground level. Old central branches are removed at the root, and new shoots are gathered into a bunch, shortened to a height of 1.5 m, and loosely secured to the trellis.
- The rope (horizontal) method is suitable for training both climbing and creeping varieties. Long, flexible stems are wound in a spiral around a support on one side, and the growing shoots are similarly secured on the other side. With this method of staking, the fruit harvest will alternate each year. In the fall, spent fruiting shoots and weak and damaged young shoots are completely cut back.
Caring for the crop
Caring for fruiting bushes in mid-autumn helps the plant grow stronger, preserve as many shoots as possible for the next season, and form fruit buds on young shoots.
Caring for blackberries in autumn:
- pruning;
- top dressing;
- shelter.
Pruning rules
The type and complexity of the work depends on the age of the branches, the variety, and the type of plant. Upright bushes produce numerous shoots from the underground part. Top pruning encourages the growth of lateral stems, which will produce flower buds and ripen fruit.
Creeping, highly branched species do not form root suckers, but instead produce numerous lateral fruiting shoots. During the summer, vines over 10 meters long become densely intertwined, making the plant difficult to maintain.
Before pruning, inspect the plant to determine the condition of the shoots. Healthy shoots are brown, shiny, bend easily, and do not break. As the bush develops, separate intertwined stems, separating fruiting branches from young shoots. Trailing varieties are removed from the trellis and laid on the ground. Five to ten strong shoots are left for the winter. They are marked with fabric tape to prevent accidental pruning.
How to properly prune blackberries for the winter:
- Using pruning shears, completely remove spent fruiting branches. They are cut off at the root, leaving no tips exposed to the soil surface.
- Broken young branches, thin, too short, damaged and diseased shoots are trimmed.
- In remontant varieties, all branches below ground level are cut off.
- To form lateral shoots, annual stems are pinched immediately above the bud: straight varieties at a height of 2 m, creeping varieties at 3 m.
- When thinning upright varieties, leave 4-7 strong shoots, and 8-10 for trailing varieties. The distance between shoots should be 8-10 cm.
- Mature young stems are cut by ¼, collected into a bunch, and secured to the ground or a low support.
- Stems that will overwinter without cover are shortened to the same height - from 1.5 to 1.8 m.
Pre-winter watering and fertilizing
After removing the suckers, the blackberries are fertilized with potassium and phosphorus fertilizers. Compost with added superphosphate is dug under each bush. Carefully dig the soil under thornless blackberry bushes. Damage to the root system of some varieties can cause thorny suckers to appear.
If the autumn is warm and rainless, water the blackberries generously before covering them. At least 20 liters of water should be poured under each bush. This will ensure the soil remains moist, the root system continues to grow, and the plant will not weaken over the winter.
To protect blackberry bushes from pests hiding in the soil for the winter, use copper sulfate or a 3% hydrogen peroxide solution. The solution is sprayed on the above-ground parts of the plant, disinfecting the soil. The peroxide acts as a beneficial fertilizer for the blackberry roots, enriching them with oxygen.
Shrub shelter
Cultivated varieties are less resistant to severe frosts than bushes grown in the forest. Blackberries grown and brought from northern regions survive the winter well. Trailing varieties can withstand temperatures as low as -16°C, while upright varieties can withstand temperatures as low as -20°C. Before covering, rake fallen leaves from under the bushes, and mulch the beds with dry humus. Blackberry stems are bent to the ground, laid in a trench on a prepared mat, and secured to the ground with hooks or metal arches. The mat is made of pine needles, chopped grass, thin branches, and bark.
Trailing varieties bend and curl easily, while upright branches resist sharp bends and can be easily broken. To prevent damage to the plant, weights are attached to the tops of the stems after pruning. The weight will gradually cause the branches to bend and fall to the ground. They are tied with twine, treated with copper sulfate, and weighed down with boards.
For the top cover, use agrofibre or organic insulation (corn, straw, wood chips, reeds, leaves, or grass). Film is not suitable as a primary cover. It is laid as an additional top layer over the insulating material to protect against moisture. Organic insulation retains heat well, but in the spring, rotted and damp plants can be difficult to remove from thorny bushes.
During winter, wet foliage attracts rodents, which damage young blackberry stems. To prevent this, place a pest bait in the center of the bush. A layer of pine needles, spruce, and pine branches prevents pests from establishing a nest. Spruce branches are placed on the plant along with film or agrofibre.
Thornless varieties are covered with green manure, and for the winter, with peat and 4-5 layers of dense spunbond. The non-woven material is dug in or pressed down with long boards.
The future harvest depends on autumn gardening. Timely blackberry care and shoot growth monitoring allow you to harvest 1.2 to 1.6 kg of delicious and nutritious berries from each bush next year.