Blackberry in Zone 7A — Midwest

Growing blackberries in the Midwest is incredibly rewarding. Imagine sinking your teeth into juicy, sun-ripened berries you've grown yourself. Blackberries are fantastic for pies, jams, or just eating fresh off the vine, and they thrive in our fertile soil and warm summer weather.

Our Midwest weather can be unpredictable, with cold winters and occasional summer heat spells, but blackberries are surprisingly adaptable. With a good start in spring and the right care, you can easily enjoy a bountiful harvest during our 193-day growing season.

You can transplant blackberry bushes outdoors from early April through early May here in the Midwest. Before planting, it's crucial to harden off your bare-root canes or potted plants. Gradually expose them to the outdoors for about a week to acclimate them to the Midwest weather.

Space your blackberry plants about 3-5 feet apart to give them plenty of room to grow. Keep an eye on the weather forecast; we sometimes get a late frost that can damage young plants, so be ready to cover them if needed. Blackberry care is very similar to raspberry care, so if you have experience with those, you're already ahead of the game.

Blackberries need consistent moisture, especially during their fruiting period, but they aren't as thirsty as raspberries once they're established. In the Midwest, our wet-summer rainfall (30-40 inches annually) usually helps, but you'll still need to monitor the soil.

Check the soil moisture by sticking your finger about 2 inches deep. If it feels dry, it's time to water. Aim for about 1-2 inches of water per week, especially during hot summer spells. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our moderate-to-humid climate.

Signs of underwatering include wilting leaves and dry, crumbly soil. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch around the base of your plants helps retain moisture and regulate soil temperature, which is especially useful during our occasional summer heat spells.

Blackberry vines are vigorous growers and need strong support to keep them off the ground and prevent them from sprawling. A trellis system works best for most blackberry varieties. It keeps the fruit accessible and improves air circulation.

Install your trellis before or at the time of planting to avoid disturbing the roots later. Train the canes to grow along the trellis wires as they develop, tying them loosely with garden twine. If you're just starting out, consider thornless varieties; they're much easier to manage on a trellis.

Pruning is essential for maintaining healthy and productive blackberry plants. After harvest, remove the spent floricanes (the canes that fruited) at the base. These canes won't produce again.

During the growing season, tip-prune new primocanes (the current year's growth) at about 4-5 feet to encourage branching and more fruit production next year. As our first frost approaches around mid- October, remove any dead or diseased canes to prepare the plants for winter.

You can expect your first blackberry harvest from early June through late July in Zone 7A of the Midwest. Blackberries are ready to pick when they're fully black, not just dark red, and they should pull off the vine easily without squeezing. A dull surface (instead of shiny) is another sign of ripeness.

Gently grasp the berry and pull it away from the plant. Avoid yanking, which can damage the cane. Blackberries don't ripen off the vine, so only pick the ones that are fully ripe. Keep harvesting regularly to encourage continued production. As the first frost approaches in mid- October, harvest any remaining ripe berries and consider covering the plants if a hard freeze is predicted to extend your harvest a bit longer.

Here are some common problems you might encounter growing blackberries in the Midwest:

Spotted Wing Drosophila

• What it looks like: Tiny flies lay eggs in ripening fruit, causing soft spots and rotting. You might see small larvae inside the berries.
• What causes it: These pests thrive in our moderate-to-humid summers.
• How to fix/prevent it: Use netting to exclude the flies, or apply organic insecticides labeled for spotted wing drosophila. Remove and destroy infested fruit promptly.

Cane Blight

• What it looks like: Canes develop brown or purple lesions, often near wounds or pruning cuts. The leaves may wilt and die.
• What causes it: Fungal disease that enters through injuries, especially in wet conditions.
• How to fix/prevent it: Prune out infected canes at ground level. Disinfect pruning tools between cuts. Ensure good air circulation to reduce humidity.

Orange Rust

• What it looks like: Orange pustules appear on the undersides of leaves in spring. Infected canes may be stunted and produce few or no berries.
• What causes it: Systemic fungal disease that overwinters in the plant.
• How to fix/prevent it: Remove and destroy infected plants entirely, as the disease is systemic and cannot be cured. Choose rust-resistant varieties.

Japanese Beetles

• What it looks like: Metallic green beetles skeletonize leaves, leaving a lacy appearance. They can also damage ripening fruit.
• What causes it: These beetles are common in the Midwest and are attracted to many plants, including blackberries.
• How to fix/prevent it: Handpick beetles and drop them into soapy water. Use row covers to protect plants. Apply insecticides labeled for Japanese beetles if infestation is severe.

Midwest Specific Challenges: Our moderate-to-hot heat and moderate-to-humid humidity create ideal conditions for fungal diseases and certain pests. Good air circulation, proper pruning, and vigilant monitoring are key to keeping your blackberry plants healthy in the Midwest. The wet-summer rainfall can also exacerbate fungal issues, so be mindful of watering practices.

Companion planting can help your blackberry plants thrive. Tansy can deter pests like Japanese beetles. Garlic also acts as a natural pest repellent, protecting your blackberries from various insects. Green beans fix nitrogen in the soil, benefiting the blackberries' growth. Mint can attract beneficial insects, but be cautious, as it can spread aggressively.

Avoid planting tomatoes, peppers, or potatoes near your blackberries. These plants are susceptible to similar diseases, such as blight, which can spread to your blackberry plants.