Rose Rosette is a viral disease of roses. It is spread by feeding of the tiny eriophyid mite Phyllocoptes fructiphilus and is very common on Knockout roses. Unfortunately, there are no chemical controls for this type of mite available to consumers.
When a rose shrub contracts Rose Rosette, highly unusual symptoms develop in the plant.
- Stem bunching or clustering, causing a "witches broom" appearance.
- Bright red leaves and stems.
- Leaves are distorted and twisted.
- The stems grow slowly and produce excessive thorns.