Why do the leaves on my rose bush have black spots?
You have a fungus called Rose Black Spot Disease. It isn’t a real disease, it is one of two fungus (Diplocarpon Rosae or Cercospora Rosicola), and can be eradicated and controlled with a fungicide spray made just to kill Black Spot. Purchase the spray at any Garden Shop or Home Center. The leaves already infected will drop off, the spray will keep it from infecting and killing new leaves just budding out and leaves not yet infected. It is the same black fungus that will grow in your shower and wash basins and toilet if you don’t keep them clean. Spraying your bathroom fixtures with bleach will keep the fungus out of the bath room, but don’t spray your Roses with bleach, it will kill the roses.
