Rose Disease

Question

We don’t know if our roses have Botrytis Blight or something else. We live in Oregon where roses thrive. However, we have experienced a historic wet and cool spring. All of our established roses in the ground and pots set new growth and blooms, then the leaves and the blooms droop. We don’t see the spots or blotches that are described in the blight, but we have lesions on some of the stems. We just purchased new plants at a local nursery, and they are doing the same thing. Could it be a soil issue? Our roses have been spectacular for 10 yrs. Our local nurseries haven’t been able to help us.

Answer 1

The wet and cool spring can lead to the soils being overly wet and thus depriving the root zone of oxygen and smothering the roses. Here an article that may help: https://www.gardeningknowhow.com/ornamental/flowers/roses/botrytis-blight-roses.htm

Spraying the roses with a product called Mancozeb (available through rosemania.com) might be a good idea and mix it together with some Immunox fungicide. This double fungicide treatment will help gain some control of the tougher fungal problems. However, I also recommend that you go to the American Rose Society website and look up your State to see if there are any Consulting Rosarians nearby. They can come by for a garden visit to see what might be happening first hand. Since you have grown roses successfully there for 10 years, I do not think it is a soil problem; but a soil test never hurts. If you have not been using an organic rose food as part of your feeding program, I would highly recommend that as well. The chemical fertilizers can lead to salt buildup, which will have similar signs as what you are currently experiencing. Two great soil and nutrient additives for roses are alfalfa meal and kelp meal.