Rose bush-Yellow leaves, no blooms
I have 3 different roses planted in a row, all planted last year where they thrived all year. They wintered well and I pruned them to within 12" of the ground this Feb. The 2 plants on each end are thriving and have a ton of buds getting ready to open. Aside from some pesky insect nibbling on one, those two are doing well. The middle plant as grown marginally taller but not really any fuller. It has sprouted leaves, which never turned a deep green and are now yellowing, and has no buds at all. What could cause only one plant to react this way?
It could be that the rosebushes you have are grafted rosebushes. This means that the upper desired part of the rosebush was grafted onto a hardy root stock to help in survive in various climates. Sometimes the upper part dies over winter for one reason or another and the hardy root stock sends up its own shoots/canes. That could be what is going on in your garden, especially if the leaves structure and color are different. In such a case, you will need to dig the affected rosebushes out and buy some new ones. Too much water, leaving the root zone soggy can cause such problems too.