How to properly prune your roses
When I prune hybrid tea, grandiflora and floribunda type roses, my first step is to cut the entire plant off to about three feet tall, except for tree roses, climbing, and miniature roses. This allows me to see the entire plant easily.
The second step is to remove the dead, damaged and diseased branches. (Branches in roses are called canes.) The next step is to remove suckers. Any canes growing below the bud union are called suckers. The bud union is the location (usually at the base of the plant) where you will notice a large swelling of the trunk.
I need to remove any canes that start growing on one side of the plant and grow through the middle. These are called crossing branches. I now want to select three to seven canes to leave on the rose bush. I am looking for canes that are spaced symmetrically around the bush when I look straight down on the bush.
I like about half of the canes to be new wood keeping my rose bush rejuvenated. The newer canes should be thick, healthy green branches. The older canes will have brown stems. All other canes should be removed now. The rose bush should look like a vase after this step, meaning there should be an open center with branches all around the edge.
The last step is to re-cut all the remaining canes back between 18 and 24 inches high, just above a plant growth bud. A growth bud is just above a leaf or where a leaf was before it fell off. The bud should be facing out away from the center of the rose bush.
If the winter has been cold and all the leaves have fallen off the rose bush, I try to cut back closer to 18 inches. If the winter has been warmer and there are still leaves left on the plant, I cut back closer to the 24 inches or even 30 inches. So far this year I will be pruning closer to 30 inches.
In the landscape you may have some roses in protected areas that require less pruning than roses in cold areas. The key is to see how many leaves are still on your roses.
Tree roses and climbers are not pruned the same way as I explained above. A climber rose would be cut back to about 5-foot-long canes. A tree rose is pruned the same as above, but the bud union is about three feet above the ground. This means the last cut should be 18 inches above the bud union, not the ground.
The key to a successful rose pruning is to cause the rose bush to grow back next spring as large or slightly larger than before it was pruned. If the rose does not grow as big next spring then make the last cut higher next winter.
As with any pruning, keep your tools sharp and clean. With the wet winter, be sure to disinfect your shears with one part bleach and nine parts water between each rose that you prune to help prevent spreading of some diseases.
If you had problems with mildew, rust or black spot on your roses last year be sure to remove any remaining leaves, flowers, or hips from the plant and the ground. Spray your plant with a fungicide labeled for roses and mildew. Also, spray the ground around your plants especially if you have decorative bark covering the soil.
There are probably more books written on roses than any other gardening topics. Many of these books are very regionally written and deal only about rose growing in that specific area. When buying any gardening book, check and see where the book is published and where the author is located.