My rose leaves have yellow markings on them. Is this a disease?
Leaves which show the veins a bright yellow or white have a disease called mosaic virus disease. This is not confused with a mineral deficiency pattern as mosaic disease is easy to diagnose when they show up on the leaves. Many plants do not even show any symptoms but still have the disease. It is usually caused by virus infected rootstock. Mosaic virus is not fatal but can over time weaken a rose so that it succumbs to other rose problems. Tests have proven that the only way it can be transferred to another plant is by using the infected rootstock. As the disease is systemic the entire plant will be infected.