Roses have a reputation for being fussy, hard to grow plants. But the reality of roses is far different from the reputation. Growing roses is a simple matter of recreating the conditions ideal for the plant. However, if you want your roses to thrive, you should give them the proper fertilizer.
Fertilize your bushes in the winter, just after pruning.
Mix one cup cottonseed meal, one cup bone meal or superphosphate (0-20-0), ½ cup fish meal, one half cup of blood meal and ½ cup Epsom salts. This will be enough for one medium-size rose bush.
Water the ground thoroughly.
Spread this mixture around the perimeter of your rose bush.
Rake this mixture into the dirt to a depth of 2 inches.
Water thoroughly again.
Apply ½ cup of commercial rose fertilizer for each rose bush twice a month until late summer.
Water your rose bushes well before and after applying the commercial fertilizer.