Viruses
Viruses are not contagious between roses in the garden and if present will have been there since the plant was propagated.
Most commercial growers produce their plants by budding scions of a variety onto a rootstock and if the material they took the scion from was infected so will the new plant be. Rose mosaic is the worst of the viruses manifesting itself as wavy yellow lines or white blotches on the leaves. Although there are others they are of less significance. Viruses are not life threatening and at worst will cause somewhat stunted growth and blooms. Some varieties of roses have had a virus of one form or another for many, many years and because of this it is nigh on impossible to find a clean plant. Indeed, we may not recognise that a variety has a virus simply because we have always known it to be the same. Scientists have found that they are able to kill off a virus therefore creating clean stock but this can only be done under laboratory conditions and is not yet available to the nurseryman. As a rose with a virus is not contagious the best way to deal with it is simply to ignore the fact that it has it and enjoy it for what it is. Some of our most lovely roses have them.
