Blackberry in Zone 6B — Great Plains

Blackberries are a fantastic addition to any Great Plains garden, offering a taste of summer sweetness that's hard to beat. Fresh berries are delicious, but you can also use them in pies, jams, or even blackberry wine. Plus, there's a real sense of satisfaction in harvesting your own fruit, especially in a region where we cherish every bit of our growing season.

Our region's extreme weather can be a challenge, with temperature swings, wind, and the occasional hail. But with a bit of planning and the right timing, you can successfully grow blackberries. Our 198-day growing season gives you a good window to get them established and producing.

Transplant your blackberry plants outdoors from early April through early May. This gives them time to settle in before the heat of summer hits. Before planting, remember to harden off your bare-root canes or potted plants. Gradually expose them to the outdoor elements for about a week.

When you're ready to plant, space them 3-5 feet apart. Keep an eye on the weather forecast. A late frost or unexpected cold snap can set them back. Be ready to cover them temporarily if needed.

Blackberries need consistent moisture, especially when they're fruiting, but they aren't as thirsty as raspberries. Once established, they are more drought-tolerant, but don't let them dry out completely. Mulch around your plants to help retain moisture and keep the soil cool. This is especially important in our hot Plains summers.

During the growing season, give your blackberry plants about 1-2 inches of water per week, either from rainfall or irrigation. Stick your finger about 2 inches deep into the soil near the base of the plant. If it feels dry, it's time to water. Water at the base of the plant rather than overhead to minimize fungal diseases, which aren't usually a big problem in our low-to-moderate humidity, but it's still good practice.

If the leaves are wilting and turning yellow, you might be overwatering. If the leaves are dry and crispy around the edges, they likely need more water. Consistent watering is key to a good harvest.

Blackberries are vines, and those vigorous canes need strong support to keep them off the ground and make harvesting easier. A trellis system works best. You can use a simple two-wire system strung between sturdy posts or a more elaborate T-post trellis.

Install your trellis before or at the same time you plant your blackberries. This prevents disturbing the roots later. As the canes grow, train them along the wires, weaving them in and out or using twine to secure them. Also, consider our Plains wind. Align your trellis to minimize wind exposure or use a solid fence as a windbreak. Thornless varieties are much easier to train on a trellis.

Blackberries require minimal pruning, but it's essential for good fruit production. After harvest, remove the old floricanes (the canes that fruited). Cut them back to the ground. These canes won't produce fruit again.

During the growing season, tip-prune the new primocanes (the canes that didn't fruit) when they reach about 4-5 feet tall. This encourages them to branch out, leading to more fruit the following year. In late October, as the first frost approaches, don't do any major pruning. The goal is to let the plant naturally harden off for winter.

You can expect your first blackberry harvest from early June through late July, depending on the variety and the weather that year. The berries are ready to pick when they're fully black, not dark red. They should pull off the stem easily without squeezing. A dull surface, rather than a shiny one, also indicates full ripeness.

Gently grasp the ripe berries and pull them from the plant. Avoid squeezing them, as they're delicate. Blackberries will continue to produce over several weeks, so check your plants every few days for ripe fruit. As the first frost approaches in late October, harvest any remaining ripe or nearly ripe berries, even if they're not quite perfect. They won't ripen further on the vine.

Here are some common problems you might encounter with blackberries in the Great Plains:

Spotted Wing Drosophila

• What it looks like: Tiny fruit flies lay eggs in ripening berries, causing them to become soft and mushy. You might see small white larvae inside the fruit.
• What causes it: These flies thrive in humid conditions, but even our low-to-moderate humidity can be enough for them to become a problem. They are attracted to ripe fruit.
• How to fix/prevent it: Use netting to exclude the flies from your plants. Remove and destroy any infested berries. Insecticides can be used, but follow the label carefully and consider the impact on beneficial insects.

Cane Blight

• What it looks like: Canes develop brown or black lesions, often near wounds or pruning cuts. The leaves on affected canes may wilt and die.
• What causes it: A fungal disease that enters through wounds. Our extreme temperature swings can stress the plants, making them more susceptible.
• How to fix/prevent it: Prune out infected canes at ground level and destroy them. Avoid wounding the canes during cultivation. Ensure good air circulation to reduce humidity around the plants.

Orange Rust

• What it looks like: Orange pustules appear on the undersides of leaves in the spring. The leaves may become distorted and the plant may fail to produce fruit.
• What causes it: A systemic fungal disease.
• How to fix/prevent it: Remove and destroy any infected plants. There is no cure for orange rust. Choose resistant varieties when planting.

Japanese Beetles

• What it looks like: Metallic green beetles that skeletonize leaves, leaving behind a lacy appearance.
• What causes it: These beetles are attracted to many plants, including blackberries.
• How to fix/prevent it: Handpick the beetles off the plants and drop them into a bucket of soapy water. You can also use insecticides, but be mindful of beneficial insects.

Great Plains Specific Challenges Our hot summers can stress blackberry plants, making them more susceptible to pests and diseases. Variable rainfall means you need to be vigilant about watering, especially during fruiting. Wind can also damage canes, so providing wind protection is essential.

Companion planting can help your blackberries thrive in the Great Plains.

Tansy can repel some insect pests, keeping your blackberry patch healthier. Garlic also deters pests and can help prevent fungal diseases. Green beans fix nitrogen in the soil, benefiting your blackberries. Mint, while potentially invasive, can attract beneficial insects and pollinators.

Avoid planting tomatoes, peppers, and potatoes near your blackberries. These plants are susceptible to similar diseases, which can spread between them. They also compete for nutrients in the soil.