|How do I combat roses with yellow leaves and black spots. I have consistently sprayed this summer, but can't get the problem resolved? I have a rose garden with apx 30 roses and they all have the same problem.|
Black spot is a nagging disease of roses. The best way to manage it is with resistant varieties. Your roses seem to be especially susceptible. This will require spraying on a regular basis, perhaps every couple of weeks from spring to mid fall, depending on the weather. I suggest trying products with one of the following ingredients: tebuconazole (Bayer Advanced Disease Control), myclobutanil (Spectracide Immunox), propiconazole (Banner and several others).