Black Spot on Roses
In the spring, my roses were full of leaves and had a lot of blossoms. This year the leaves have black spots, turn yellow and fall off. Some dry up, turn gray and curl up. There is new growth on the bare stems and at the base of the plant, so I know it isn't dead.
Your roses like so many other gardeners' are suffering from black spot disease. This fungal disease is common during wet weather when temperatures are around 65 to 75 degrees. Once a planting is infested with this fungus it is hard to eliminate. You can reduce future infections by removing disease infected leaves as soon as they appear. A thorough cleanup in fall will help reduce the source of disease for the following season. Avoid overhead irrigation that increases the spread of this and many other diseases. Fungicides labeled for control must be applied prior to the symptoms and usually every 7 to 10 days. Be sure to read and follow label directions. Avoid the frustration and extra work by growing black spot resistant roses in the future. Many of the new shrub roses are attractive, repeat blooming and resistant to this and many other pests that plaque roses.