Question From: Albuquerque, New Mexico, United States
Q: What causes roses the to discolor?
Leaves, flowers, stems - what part of the plant. Not enough information. I'd take a sample of the damage to your local independent garden center for an accurate ID and control, if needed. If the discoloration is very red stems that produce distorted growth and excessive growth of thorns your roses have the deadly fungal disease rose rosette. Dig out the rose and all the roots and dispose of them in the garbage. It will spread to other roses if left in the garden. Google photos of rose rosette disease for pictures. Best And Happy Yardening, Nancy.