How to Prune Climbing Roses
Climbing roses are best pruned in late summer, when you can see the shoots more easily.
Step 1: Retain Old Wood
Retain old wood, except for any diseased, dead, or weak growth, which should be cut down to the ground or to a healthy bud.
Step 2: Reduce Sideshoots
Only prune the sideshoots, reducing them to about two-thirds of their original length, and cutting to a bud facing in the right direction.
Step 3: Provide Stem Support
Tie in the newly-pruned stems horizontally to their support. This encourages more flowering sideshoots to form along the stems.
Step 4: Trim Longer Stems
Prune back any too-long stems that are protruding beyond the support, and sideshoots growing away from it.