Blackspot on Zephirine Drouhin
I returned from vacation to discover that my one year-old Zephirine Drouhin rose bush, purchased from the Antique Rose Emporium in Independence, Texas, has many yellow leaves covered with round, black spots. A few of the other antique rose bushes also have a few of these leaves, but this one is the worst. I removed the affected leaves--they almost fell off. What is the best way to treat for this? I've tried to use no pesticides, etc., but I am now willing to use whatever it takes. Can't bear to think of a life without roses.