Work some good compost into the soils around the rosebushes and add some alfalfa meal and or kelp meal in at the same time. This will help build the soils up to make the roots happier. Sometimes the soils need to be built up to allow all the nutrients available in the soils to get into a form the roots can take them up well through. Also after working in the amendments above, give each of the roses 1/2 cup of Epsom Salts spinkled around the base of the rosebushes and worked lightly into the soils, then water them well. This will all help give them a bit of a kick start to doing better.
Stan The Roseman