Blackberry

Question

My blackberry bush produced fruit first two years and now is a small tree. (unknown tree)

Answer 1

These links have information on growing Black Berry's.

https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberries-not-fruiting.htm
https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberry-pruning.htm