I have a red raspberry bush. This year's cane growth has taken off since last year's canes bore fruit and were removed. The canes are easily now over 8-10ft long. They're getting to the point where I have to move them around to mow grass. When can I prune them back to a more reasonable length?
Hi- if the fruit ripened in June and the cane died and was removed you have a "June-bearing" cultivar. The shoot that grew from the crown of the plant this year and is 8-10 ft. long should be immediately pruned to 4-5 ft. It will flower and fruit in the spring.
Next year, be sure to prune back the new, soft canes that emerge in spring to 4 ft. in June/July. The laterals that grow from that pruning cut will also need to be cut back to 2-3 ft. in length.
Read more about the two main types of raspberry plants: https://extension.umd.edu/hgic/topics/raspberries-and-blackberries-brambles