Hello. The roses seem to show symptoms specific to black spot (Rose black spot (Diplocarpon rosae) - identify and control). In the absence of more information and photos, you may consider following the recommendations detailed in a similar topic in the Armuro Community: https://www.armuro.com/en/forums/about/roses-yellowing-stained-leaves/. Additionally, it is recommended to remove the layer of gravel at the base of the plants, as this maintains a constant and high humidity in the soil. Further, it is recommended to keep a portion of loose, vegetation-free earth around each rose bush. Since the activity and spread of plant pathogens is stimulated by high and constant moisture in the soil, watering is recommended to be carried out according to the recorded temperatures and rainfall only when the soil is dry on the surface. It is recommended to regularly remove all affected leaves or plant parts. In order to stimulate the healthy growth of roses, you can consider fertilizing them regularly in the future.