Blackberry Care Guide

Blackberries (Rubus fruticosus) are hardy perennial plants that grow in a biennial cycle. This means the root system remains alive and perennial, while the canes (stems) grow, fruit, and die off after two years. Proper care and maintenance will ensure that you get a bountiful crop year after year. This guide will cover the essentials of soil preparation, planting, mulching, watering, pruning, and harvesting for successful blackberry cultivation.

Soil Selection

Blackberries thrive in well-drained soil rich in organic matter. The ideal soil should be:

• pH: Slightly acidic, between 5.8 and 6.8.
• Texture: Sandy loams, loamy soils, or soils with a mix of sand or clay.
• Organic Matter: Aim for at least 2% organic matter for the best growth. Blackberries are heavy feeders, and organic matter will help with nutrient retention.

Blackberries also prefer a well-drained soil as they do not tolerate wet feet (excess moisture around the roots). Avoid planting them in heavy, clay soils unless well amended.

Planting Blackberries

1. Timing: Blackberries can be planted year-round, weather permitting. Ideally, plant them in early spring or late fall when the soil is workable and temperatures are mild.
2. Spacing:
• Space plants 5 feet apart in rows, ensuring they have enough room to grow. The rows should be spaced 5 feet apart as well to give ample space for plant spread and air circulation.
• Blackberries are vigorous growers, and good air circulation reduces the risk of disease and pest issues.
3. Plant Depth:
• Plant your blackberry bushes at the same depth as they were in the pots. This is critical to avoid crown rot or poor growth.
• Ensure there is at least 4 inches of good soil for the roots. Blackberries don’t have deeply penetrating roots, so shallow, well-drained soil works best.
4. Support:
• Some varieties like Arapaho, Apache, and Schultz don’t need a trellis for support, while others like Triple Crown can be summer pruned to maintain an upright stature. Semi-erect varieties tend to eventually support themselves as they mature.

Mulching

Mulch is key for blackberry success, offering benefits like weed suppression, moisture retention, and temperature regulation. Here’s how to mulch effectively:

• Mulch Depth: Apply a 4-6 inch layer of mulch around the plants. This helps keep the soil moisture consistent and provides nutrients as it decomposes.
• Types of Mulch: Use materials such as straw, old hay, sawdust, or wood shavings—ensure they are free of weed seeds.
• Timing: Apply mulch in the fall or early spring, when soil moisture is high. In winter, adding manure to the mulch can enrich the soil, providing an extra boost in early spring. It’s also a good time to remove perennial weeds and maintain a healthy spacing between plants since they do tip root and can become over-crowded, especially the trailing types. 

Watering

Blackberries need consistent moisture, especially during the growing season and leading up to harvest. They require about 1 inch of water per week, which can be delivered through:

• Drip irrigation: Efficient and water-conserving, this is an excellent way to ensure your blackberries receive consistent moisture.
• Watering Time: Water deeply at the base of the plants, ensuring the roots get enough moisture. Avoid overhead watering, as it can promote fungal diseases.

During dry spells, especially at harvest time, make sure the plants have access to extra water. This helps the fruit grow larger and sweeter.

Pruning and Maintenance

Proper pruning is essential to maintain healthy blackberry plants and ensure a productive harvest. Here’s how to handle pruning and cane management:

1. Canes (Primocanes and Floricanes):
• Primocanes are the new, green canes that grow in the current year. Primocanes can be tipped, usually in June, to encourage lateral branching. 
• Floricanes are the mature canes that will flower and bear fruit in their second year, before dying off after fruiting.
2. Pruning After Fruiting:
• Floricanes (the canes that have fruited) should be pruned out after they have finished fruiting. By winter, they will be easy to identify as they will look different from the new canes.
• Primocanes should be left untouched, as they will produce fruit in the following season.
3. Maintaining Cane Height:
• Keep canes between 4 to 6 feet tall. When canes grow taller than this, pinch them back at chest height to encourage lateral growth.
• Lateral branches (side shoots) should be 15 inches long. Pinch them back if they get too long during the growing season.
• Maintenance of cane height should be done in Summer and stopped by September. 
4. Tip Layering:
• Blackberry plants can spread by tip rooting. If new shoots are crowding the planting bed, dig up the rooted tips and transplant them to give the plant more space.
5. General Maintenance:
• Prune any dead or damaged canes to keep the bed tidy and disease-free.
• Maintain good air circulation by thinning out overcrowded canes. This will help the plants stay healthy and make it easier to harvest the fruit.

Harvesting Blackberries

Blackberries are ready to be harvested when they are firm, fully ripe (black), and come off the plant with a slight touch. Here’s how to tell when to harvest:

• Color and Texture: The berries should be shiny black, not red or purple. At first, they may be tart, but they will sweeten over a few days.
• Picking Method: Gently twist or pull the berries from the stem. Blackberries should fall off easily with minimal pressure.

Weed Control

Weeds can compete with blackberries for nutrients and water, so keeping them at bay is essential:

• Mulching: As mentioned earlier, mulching is an effective method for controlling weeds.
• Weed Cloth: Laying down weed barrier fabric can be a game-changer for minimizing weed problems. Staple it securely to the ground to keep grass and weeds from invading your blackberry bed.

Example of a Blackberry Bed Setup

• Location: Start by mowing a section of your lawn and tilling the area 2-4 inches deep. Add organic matter like old potting soil, mulch, and manure to improve soil quality. 
• Planting: space each plant about 5 feet apart in a row. 
• Trellis: Install stakes with wires for the blackberry varieties that need support, and ensure plants are spaced properly. 
• Mulching: after planting, apply a 3 inch layer of hardwood mulch to retain moisture and suppress weeds. 
• Maintenance: minimal upkeep is required once the plants are established. Simply prune away established floricanes after fruiting and keep the beds clean. 

Common Problems and Pests

1. Pests:
• Japanese Beetles: These pests may chew on leaves and fruit. Beetle Gone works best to control these in our experience. 
• Spider Mites: These can cause a webbing effect on the canes. Treat with a miticide or insecticidal soap if needed. Spider mites usually appear when the plant is already under stress like drought, so be sure to consider the potential causes. 

Spotted Wing Drosophila: similar to kitchen fruit flies, these pests lay their eggs in the druplets(individual units that make up a blackberry), causing uneven ripening or rotting of the druplet. Insect netting is helpful in controlling the population of these. Well draining soil and good pruning maintenance helps too. Earlier ripening varieties like Arapaho and Ponca can be good choices for areas (much of the Southeast) where this is a prevalent issue. 

1. Diseases:
• Botrytis Fruit Rot: A common fungal disease, particularly in wet conditions. Remove infected berries and ensure good air circulation.
• Cane Blight: A bacterial infection that causes wilting and dieback. Prune and remove infected canes immediately.
2. Birds: Birds love ripe blackberries. Netting can be used to protect your fruit during harvest.

Conclusion

Blackberries are rewarding plants to grow, offering delicious fruit year after year with the right care. By ensuring good soil, proper spacing, regular pruning, and effective mulching, you can enjoy abundant crops for many seasons. Whether you're growing them for fresh eating, preserves, or freezing, these hardy plants will become a valuable part of your garden.