When and how do I prune raspberry plants?
Certified GKH Gardening Expert
This article should help with that: https://www.gardeningknowhow.com/edible/fruits/raspberry/pruning-raspberry-bushes.htm
old canes are cut out, new canes produce growth. cut out in late fall or spring. You can also plant raspberries that can be mowed in the fall and never have to cut or trim because growth comes from the new growth not last years canes.