Regular upkeep in the garden is one way to safeguard against the gray, fuzzy mold called Botrytis Blight (Botrytis cineraria). Cleaning up spent flower spikes and leaf litter eliminates host material for Botrytis. During spring clean-up, thin the branches of woody Salvias to create more air circulation, which discourages mold. Divide and transplant overgrown herbaceous species.
If parts of a plant show Botrytis, trim and bag them for disposal, being careful not to spread the spores. Similarly remove and bag whole plants that are infected. You also may need to treat soil in which an infected Salvia was planted with an organic disease control product.