I have yellow leaves on one section of my most vigorous rose. It's definitely not black spot or any other fungus. The leaves look healthy, and haven't changed over several weeks. It's just that they're yellow instead of green. Any ideas what this might be? Note. The rose lives on the edge of a compost pile. That's why it's my most vigorous one, I'm sure. It's a Climbing Dublin Bay.
For the first time this year I have the same problem with only one of my roses--"Gertrude Jekyll." No black spots, only yellow leaves. I have been using Mills Magic Mix in the ground and fish emulsion as a a foliar fertilizer. However, I just started using the foliar application since the yellow leaves already had appeared. Do you think I still need some liquid iron for just that rose bush, anyone? Thank you!