This is an excellent plant from Mexico, which flowers basically all year round. It is dainty, and grows to about 60cm with shiny leaves and slender flower stems with velvety cerise little flowers giving a haze of colour. It needs a spot where it won't be overgrown by bigger plants. It does tolerate a bit of shade but is most floriferous in a sunny spot. It looks pretty with silver or cerise leaves nearby; pink or blue flowers are also attractive with it - it is very pretty in a cottage-style garden. Annual browallia (Browallia americana) is an excellent companion, being of the same height, as is shrubby Plectranthus saccatus, with milky blue-mauve flowers in summer and autumn. This salvia can be grown in a pot. As it flowers year round, it can be kept in good shape by the occasional removal of a couple of stems, or else can be cut back hard in late winter when most other salvias are pruned. It also benefits from deadheading of spent spires. It does get attacked by a nasty little black flea beetle which disfigures the foliage: try squashing the little bugs each day or give the plant a good pruning to encourage fresh new growth. It is frost-sensitive.
Postscript: I no longer grow this species as it was regularly ruined by flea beetles in my garden!