Rose Rosette Disease
Rose rosette virus
A deadly viral disease of roses, spread by a tiny wind-blown mite, that throws out clusters of distorted red shoots, excessive thorns, and witches-broom growth before killing the plant. It has spread widely across much of the country and has no cure, so prompt removal of infected roses and control of the mite are the only options.
🔎 How to spot it
Look for a tight cluster of spindly, distorted, often bright red shoots, a witches-broom, along with rapid elongation, leaves that are small, deformed, and mosaic-mottled, and canes that are thickened, unusually flexible, and covered in excessive soft thorns. Affected roses decline and usually die within a couple of years.
🥀 Damage it causes
Rose rosette deforms and weakens the rose and is ultimately fatal, killing affected plants within one to a few years. Because the mite that carries it drifts on the wind to nearby roses, one infected plant threatens every rose around it, which is why quick removal matters so much.
🔬 What causes it
Rose rosette is caused by the rose rosette virus, spread by a microscopic, wind-blown eriophyid mite, Phyllocoptes fructiphilus, that feeds on roses. The mite picks up the virus from an infected rose and is carried by wind to others. The wild multiflora rose is a major reservoir, and the disease is common across much of the country east of the Rockies.
🛡️ Prevent it
Avoid planting roses right against each other so mites cannot move plant to plant as easily, and remove nearby wild multiflora rose, a key reservoir. Inspect roses often and act fast on any witches-broom growth. Knocking back the eriophyid mite is difficult, but pruning roses back hard in late winter removes overwintering mites on the canes.
🧯 If it is already here
There is no cure, so dig out and destroy the entire infected rose, roots and all, as soon as the symptoms are confirmed, and do not compost it, to stop the mite from spreading the virus to neighbors. Replant with clean stock, and because the mite is hard to control with miticides in the garden, removal of infected plants is the dependable control.
💡 Good to know
The bright red, thorny witches-broom is the hallmark of rose rosette, though normal new rose growth can also be reddish, so look for the combination of distortion, excessive thorns, and broom-like shoots. Because the disease is fatal and mite-spread, removing infected plants promptly protects the rest of the garden; there is no saving an infected rose.
🌱 Plants it affects
13 plants in the library can be affected by this problem
For educational and informational purposes only. Disease management advice is general guidance drawn from university cooperative extension sources; always identify a problem positively and read and follow the label on any product before use, especially around food crops, children, and pets.