Remove the bloom spikes of salvias after blooms have faded to encourage continuous bloom. Wait until new growth begins to emerge in early spring to do your winter cleanup of old stems to avoid freeze damage to the less hardy types. The best time to divide perennial salvias is in early spring, before new growth begins. They can be subject to damping-off of seedlings, stem and root rots, powdery mildew, Botrytis blight, aphids, spider mites and whiteflies. Diseases are most common either in greenhouses or under conditions that salvia dislike such as cool, wet weather.
Insects are mainly problems in greenhouses.
With over 900 species of salvias, there are far too many to give more than a few of the more popular types here. Many of the tender perennial species are popular as annuals where they are not fully hardy. Some of the types most commonly grown as annuals are listed below. In some cases they may also be grown as perennials in warmer areas of South Carolina. Scarlet sage has bright red flowers in whorls on 10-inch spikes.