How Should I Prune My Second Year Blackberry Bush?
I read the article this website has about pruning blackberry bushes and found it helpful. However, my actual question was not answered. I bought a second year small sized blackberry bush from Lowe's a couple months ago. I planted it and it has been doing well. It flowered and now has premature berries growing. There is a large, tall shoot (about 3 feet long) growing out of the center of the bush. I am worried that this shoot is taking away from the growth anywhere else on the plant, as the other part of the bush has not grown at all (although the berries continue to mature). Should I cut off this shoot or leave it?
Leave it. Often berry plants are trimmed to it into boxes and bags. Once the plant is in the ground, new growth is more vigorous and larger than older growth. At some point, you will need to prune the original stems so the newer, more robust canes get full nutrition. (Wait till the berries have been harvested! :) )