Rose Rosette Disease on Knock Out® Rose
Rose rosette disease (RRD) is caused by rose rosette virus (RRV). Rose rosette virus is transmitted by grafting or the feeding of eriophyid mites.
Symptoms of RRD are highly variable depending on rose species and cultivar.
- Elongation of new shoots
- Leaf reddening/mottling, distortion, and or stunting
- Clustering of small branches (“witches’ broom”/”rosette”)
- Excessive thorns that are initially soft and rubbery
- Abnormally thick, succulent new growth
- Flower buds may abort, be deformed, or converted to leaf-like tissue (phyllody)
- Flowers may be distorted, discolored, or fail to open normally
- Reduced plant hardiness/vigor
There is no cure for rose rosette disease. Symptomatic roses should be removed and destroyed.
For more information, see HGIC 2109, Frequently Asked Questions About Rose Rosette Virus.