Control
Black spot can be controlled by planting cultivars with resistance to the disease such as WEKcisbako (HomeRun®) or RADrazz (Knock Out®). These cultivars are, however,susceptible to Cercospora leaf spot. Old garden roses ‘Mrs.B.R. Cant’ and ‘Spice’ have shown good levels of resistance to both diseases in our trials. Sanitation practices, such as removal and burning of fallen leaves and pruning of canes late in the winter before new shoots are produced, help reduce the amount of inoculum. Plants should not be allowed to remain wet for long periods of time and overhead irrigation should be avoided or minimized. If this is not possible, plants should be irrigated early in the morning to allow leaves to dry.