Blackberry in Zone 3B — Great Plains

Blackberries in the Great Plains? Absolutely! Imagine sinking your teeth into a juicy, homegrown blackberry, bursting with flavor far superior to anything you'll find at the grocery store. Blackberries are fantastic for jams, pies, or just popping straight into your mouth, and the satisfaction of growing your own in our challenging climate is unbeatable.

We know our Plains weather can be unpredictable, with extreme temperature swings and the risk of hail. But with careful variety selection and attention to timing, you can definitely enjoy a successful blackberry harvest within our 118-day growing season.

Transplant your blackberry plants outdoors from mid-May through mid-June, after the last expected frost has passed. Before planting, harden off your bare-root canes or potted plants by gradually exposing them to outdoor conditions for about a week. This helps them adjust to our intense Plains sunshine and variable temperatures.

Space your blackberry plants 3-5 feet apart to allow for good air circulation. Remember that even in late spring, we can still get some strong winds, so consider a sheltered location, especially for young plants. Dig a generous hole, plant at the same depth as the nursery pot, and water well.

Blackberries need consistent moisture, especially while they're establishing and during fruiting. While more drought-tolerant than raspberries once established, don't let them completely dry out, especially in our hot Plains summers.

During the growing season, aim for about 1-2 inches of water per week, depending on rainfall. Use the finger test: stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. In the hotter parts of summer, you might need to water more frequently. Water at the base of the plant to avoid wetting the leaves and encouraging fungal diseases, which can be a concern even with our low-to-moderate humidity.

Signs of underwatering include wilting leaves and dry, crumbly soil. Overwatering can lead to yellowing leaves and root rot. Applying a generous layer of mulch, such as straw or wood chips, around the base of your blackberry plants will help retain moisture, suppress weeds, and regulate soil temperature – all crucial in our variable climate.

Blackberry vines are vigorous growers and definitely need support to keep them off the ground and manage their sprawling habit. A sturdy trellis system is ideal. T-post trellises or even a simple wire strung between posts work well.

Install your trellis system before or at the time of planting to avoid disturbing the roots later. As the canes grow, train them to the trellis, weaving them through the wires or attaching them with plant ties. Given our windy conditions on the Plains, a strong trellis is essential to prevent canes from snapping. Consider orienting your trellis to provide some wind protection, if possible. Thornless varieties are much easier to train and manage on a trellis.

Pruning is important for maintaining healthy and productive blackberry plants. After harvest, remove the spent floricanes (the canes that produced fruit) by cutting them back to the ground. These canes won't produce again.

During the growing season, tip-prune the new primocanes (the canes that didn't produce fruit this year) when they reach about 4-5 feet tall. This encourages branching, which leads to more fruit production next year. As the end of our short season approaches in late summer or early fall, don't prune too late, as you want the plant to harden off before the first frost.

Get ready for your first blackberry harvest from mid-July through early September, about 60 days after flowering. The berries are ready to pick when they are fully black, not dark red, and have a dull surface instead of a shiny one. A ripe blackberry should pull easily from the vine without squeezing.

Harvest regularly, every few days, as the berries ripen. Handle them gently to avoid bruising. Continued harvesting encourages the plant to produce more fruit. As the first frost approaches in mid-September, harvest any remaining ripe or nearly ripe berries. They won't ripen off the vine, but you can use them for jams or smoothies.

Here are some common problems to watch out for with blackberries in the Great Plains:

Spotted Wing Drosophila

• What it looks like: Tiny fruit flies laying eggs in ripening fruit, causing soft spots and rot.
• What causes it: These pests thrive in humid conditions, but can still be a problem even with our relatively low humidity, especially after rainfall.
• How to fix/prevent it: Use traps to monitor for their presence. Netting can exclude them from the plants. Remove and destroy infested fruit promptly.

Cane Blight

• What it looks like: Brown or purple lesions on the canes, often near wounds or pruning cuts.
• What causes it: A fungal disease that enters through injuries. Our extreme temperature swings can weaken plants and make them more susceptible.
• How to fix/prevent it: Prune out infected canes promptly and disinfect pruning tools. Ensure good air circulation.

Orange Rust

• What it looks like: Orange pustules on the undersides of leaves.
• What causes it: A systemic fungal disease.
• How to fix/prevent it: Remove and destroy infected plants immediately. This disease can spread quickly. Purchase disease-free plants from reputable nurseries.

Japanese Beetles

• What it looks like: Metallic green beetles feeding on leaves and fruit.
• What causes it: These pests are attracted to ripening fruit.
• How to fix/prevent it: Handpick beetles and drop them into soapy water. Use netting to protect plants.

Great Plains Specific Challenges: Our hot summers can stress blackberry plants, making them more susceptible to pests and diseases. Variable rainfall patterns mean you need to be vigilant about watering, especially during fruiting. Wind protection is essential to prevent cane breakage.

Companion planting can help your blackberries thrive. Tansy repels many insect pests. Garlic also deters pests and has antifungal properties. Green beans fix nitrogen in the soil, benefiting blackberries. Mint can attract beneficial insects, but be careful it doesn't spread too aggressively.

Avoid planting blackberries near tomatoes, peppers, and potatoes. These plants are susceptible to similar diseases, which can spread between them.