|I know to cut them off at about 30 inches to promote lateral branches. Did that. These lateral branches are very long. Should I also cut these lateral branches off?
|The new lateral branches are where your fruit will form, so don't cut them off until after you've harvested the fruit! There's always confusion over how to prune raspberries because there are two types; summer-bearing and fall-bearing, each with their own pruning requirements. Things are complicated even further if you're raising black raspberries. So, here's how to properly prune raspberries; fall-bearing are easiest - just cut the canes all the way down after they've finished fruiting. New canes will grow in the spring and produce fruit in the fall. If you have ever-bearing raspberries, cut back the fruiting part of the cane after harvesting in the fall, but leave the rest of the cane. After harvesting the following summer, prune the rest of the cane all the way down to the ground.
Summer-bearing raspberries bear fruit on two year old canes called floricanes. Prune the bearing canes off at ground level immediately after harvesting. Canes that have not produced fruit should be cut back to 4' or 5'. These canes will develop fruiting wood the following spring. If the canes are crowded, thin them in early spring, before growth begins, to 2-4 strong canes per foot of row.
Black raspberries bear fruit on second-year canes. During the summer, cut the tip off each cane when it's 2 1/2' - 4' high. This will force it to develop sturdy side branches (where fruit will ultimately develop). After harvest, cut the spent floricanes back to the ground. In the winter, thin the remaining canes, leaving 4-5 (per foot of row) of the largest, straightest ones. Prune back the side branches to 8"-12", and remove any spindly ones. This dormant pruning should remove all of the unruly canes and leave you with nice, neat groups of straight canes. You can tie them together to keep them from whipping around in the weather. Untie in the spring and train the new canes to your support. Hope this clears up some of the confusion.