Blackberries are a very hardy plant as long as you have a period of freezing during the winter months and not severe cold of below zero for several weeks. The only difference between wild and cultivated blackberries is that the wild ones are growing on their own and the cultivated ones might have some cross pollination involved in their heritage, and controlled breeding to help in their resistance to disease and pests. You can easily cultivate wild blackberries to grow in your garden and produce delicious berries.
Plan to dig up the wild blackberry bush that you wish to cultivate sometime after September when the heat of the summer is passed. Technically, you could do it anytime, but the best time is in the fall when growth is subsiding and your pruning won't cause too much regrowth before the winter frosts.
Dig around the plant about 12 inches out from the base and about 12 inches down below the soil line. The size of the root ball you can save will determine how quickly the plant adjusts to its new surroundings. Carefully lift the blackberry plant out of the ground and into a box or burlap bag for transplanting.
Prepare the receiving site by digging a hole about 6 inches larger than the root ball in all directions. Fill in the hole with a few inches of good garden soil. Set the wild blackberry plant into the space and start filling in the rest of the area with more garden soil..
Tamp the soil in around the plant as you go with the heel of your foot. Add soil until the hole is completely filled and then mulch around the plant with well-rotted compost or leaf mulch.
Water the plant well several times for the first week to make sure it has a chance to get established before the cold weather, and then once a week until the frost hits.
Tie the canes off to a trellis to keep them from growing long and arching over. These arches will hit the ground and produce new plants, quickly forming a bramble if you are not careful. Prune your canes to be about four feet high during the summer and remove any canes that have already born fruit. The pruned canes will produce side shoots that will also bear fruit.