What’s that you say? You want me to actually buy blackberries? What’s wrong with all the blackberries taking over my back yard?
Well, those are Himalayan blackberries, an aggressive Asian invader, and in addition to those incredibly painful thorns, the fruit is full of unpleasant seeds and not particularly tasty. You can do much better. Follow the same general instructions as raspberries, but make life easy on yourself and choose a thornless variety that will be easy to tell apart from any Himalayan blackberries that try to sneak in. You might also try loganberries, which are a cross between blackberries and raspberries, and tayberries, which are a cross between loganberries and black raspberries. (Raintree Nursery is a good source for all of these)