Do not let this soil drop in other parts of the garden. Replace with fresh soil. Virus Diseases Mosaic is the most common virus disease of peonies. It produces yellowish blotches and rings on leaves but it does not cause much damage Infected plants are not dwarfed or deformed. Crown elongation, another virus disease, causes many long branched crowns to develop from the tubers.
Plants develop many slender, weak shoots.
These dwarfed shoots produce no flower buds. Leaf curl, or curly leaf, virus causes plants to become dwarfed. Leaves grow close together on the stem and curl up. Leaf surfaces crinkle. No flower buds form.