My blackberries aren't bearing fruit. What could be the problem?

Question:Every year, my blackberry bushes flower but the berries fail to develop. I am wondering if the blackberry plants need another variety to cross-pollinate. Or is there another possible problem?

Answers:
One problem may be the way that you prune your berries.

Blackberries are perennial plants, with the roots living for many years. However, their canes are biennial, each one only living for two years. The first year canes are called primocanes, and bear flowers but no fruit. The second year the primocanes become floricanes, which produce fruit. After the fruit is produced on the floricanes, the cane dies.

If you trim all of the canes back at the end of the year, you will only have flowering primocanes, for none will have a chance to become producing floricanes the next year. If you wait until early spring and remove only the dead or dying canes (the old floricanes), you will have the mix of flowering and producing cane types that you seek.