Thank you for including an image with your inquiry. The dark spots on the rose leaves indicate that the rose has a common disease specific to roses, black spot of roses. Some roses are seriously affected by this disease, whereas others seldom have problems. If this is the first time you’ve seen these spots on this rose, it may one of the resistant kinds.

In any event, it’s wise to remove all intact and dropped leaves which are marked with black spot and, then, discard them in the trash. Left in place, they provide the infective units to start new leaf infections. (These particular black spots are distinctive in that the edges are fringed or feathery.)

Conditions which favor black spot of roses include free moisture on the leaves, a common condition here in the northwest. On the other hand, full sunlight and good air circulation help limit the disease.

Whenever chemical control is used, treatments begin at bud break, when the new leaves begin to grow. A wide selection of products effective against black spot of roses are available at local garden centers. 

All affected leaves should be removed as soon as you see them as a means of protecting the newest leaves as they develop. As long as the damaged leaves remain in place, they are the source of the fungus which infects the newly developing leaves.

The spotted leaves currently on the bush are from last year and will soon drop of their own accord. So, no, it won’t hurt the bush to remove them now.

Sprays are effective only when applied prior to infection. The newly emerging leaves are the ones most susceptible to black spot of roses.