What Is Growing With My Blackberry Plants?

Question

Last year, I planted 5 blackberry plants. This year, there are thick canes that tend to grow straight up growing from the roots. These canes have 5 leaves instead of 3, but look the same shape and size. Should I prune them?

Answer 1

This sounds like witch's broom. This article will explain more:
https://www.gardeningknowhow.com/ornamental/trees/tgen/witches-broom-disease.htm

You can cut them off. They will not produce fruit.