Blackberry Growing instructions
Blackberries should be planted 4-6 feet apart. Plant in late afternoon or evening and water in well after planting. New plants need to be watered daily if your temps are 65 degrees or higher. Add compost and plant in an area with good drainage and as much sun as possible. If planted in full shade, the plants will not produce fruit. Do not plant where tomatoes, peppers eggplants, potatoes, or strawberries have been grown in the past 3 years, as diseases these plants have will infect your new blackberries.
Have a 2 wire fence down the center of the row. Tie up the year old canes. After they fruit, prune out the canes that have fruited. The next spring repeat, tying up the year old canes. Fertilize with a balanced fertilizer in late spring. A compost mulch is beneficial.
Google your State or nearby State Ag college for your specific cold weather blackberry protection, as it is different in different parts of the country. Here are a few sites with growing info:
Scenic Hill Farm Nursery, 2820 NW Scenic Drive, Albany, OR 97321, 541-990-6099