I am not sure where you are located. However, here are some fine rose foods that I have used and like. Some may be available in my area only.
Mile Hi Rose Food, Locally made product in Colorado.
Gro-Rich Rose and Perennials Food - Made by Richlawn and available at some Home Depot locations.
Vigoro Rose Food, also available at many Home Depots.
Look for a rose food that has some alfalfa meal and or kelp meal in it. The roses love those two meals alot. The organic nature of the top two foods I listed help build the soils as well as feed the rosebushes.