It's best not to procrastinate when it comes to pruning climbing roses. Whether climbing roses are grown on a wall, fence, trellis, post, or pillar, I recommend pruning them every year not only to keep your climbers from overwhelming their supports but also to spare you the frustration of dealing with an overgrown snare of canes. Your roses will reward you with robust growth and more flowers.
Pruning climbers every year keeps the shrub vigorous. Removing diseased or damaged branches allows healthy new growth to replace them.