Pruning climbing roses is a little bit more of a different beast than a bush or shrub. Good habits can make it a strong grower that looks great in your garden!
With ramblers, it can often be several years before you'll see any significant blooms or flowers. During this time you really don't need to worry about a prune. Focus more on proper training and direction so that the flowers grow evenly on your arbor, trellis, or other structure.
Trim out weaker wood at the bottom of the climber. Also, be sure to cut off any canes that are in the wrong direction. A lopper is a very handy tool for this.
You also need to take into account the plant itself. A repeating bloomer should be pruned during the winter or early spring. While a one-time bloomer, should only be cut after it has bloomed for the season, removing about 1/3 of the growth. Cut the lateral canes to just a couple of buds, down to about 12 inches or so from the main canes. You can be very aggressive on the smaller offshoot canes. Some people will say that you can trim these offshoots throughout the season but its not a necessity, as long as you are doing the seasonal trimming. A good rule of thumb is that you'll get the best blooming on one year old growth. Older canes will probably not produce as much.
Sometimes you'll have a main cane that is damaged or wounded or weak. Look for one of the lateral canes off of it and find a healthier offshoot. You can then train this healthier offspring to your trells and allow the damaged cane to be a lateral offshoot. The rose will then train itself to the new configuration.
Wild roses, Hybrids, climbers, miniatures and more. Make some sense of the multitude of rose varieties with our handy guides.