Answer: The plants usually bloom best when they are healthy and growing vigorously. Depending on the type of rose you have, it may object to the constant pruning required to keep it so small. Maybe you can allow the canes to cascade back to the ground and peg them down so they trail out across the ground around the trellis. They will bloom all along the canes and you will not have to keep them short. Otherwise, you might replace them with something else that will fit the trellis better.
Q&A Library Searching Tips