Answer: There are some fungal disease of roses that can attack the canes. I would prune the infected canes out and dip the pruning tool in rubbing alcohol between cuts to avoid spreading a problem. The problem may also be at or below the soil. Carefully scrape back a little bark at the soil line on the plants showing the symptoms and see if it is a healthy cream color underneath or a pecan brown color, indicating dead tissue.
Soil that is too wet or too dry can cause problems for roses.
I would go ahead and transplant this fall. I have moved older roses several times in the south with no problems.
I have not tried the mineral oil spray, but have concerns regarding its safety for the plants. Oil sprays in the summer (temps above 90 degrees) can burn foliage, so this may be contributing to the problem.
Hope this helps. Good luck with your roses!
Q&A Library Searching Tips