My noid always look like this, even when everything else is perfect, no blackspot or any other problem on the rest of the Rose bush, but the edges of the petals look bad, a couple of time I wanted to get rid of it but feel bad because it blooms a lots every year. Do you have any idea what causing this?
Thrips would be my guess as well. Spraying the developing buds every other day with an insecticidal soap solution of 5 tablespoons of detergent-free liquid soap in 1 gallon of water may kill thrips before they cause damage.
