This salvia is the old-fashioned Mexican sage bush, growing about 1.3 m tall and it has been around for a long time, before anyone realised how many salvias come from Mexico! It hails from Central and Eastern Mexico. It is a quite drought-tolerant plant so likes a sunny position with well-drained soil. Too much water can make it lanky. It flowers from late summer or autumn into winter. It will tolerate mild frosts. The plant should be cut to the ground in winter, once the new growth can be able to be seen at the base. The species has spired og white flowers held in purple calyces, on silvery stems above woolly leaves, which are quite white underneath. A vibrant cultivar called 'Midnight' has rich purple flowers nearly the same colour as the calyces, Salvia leucantha looks good with blue, pink or cerise flowers, or with orange flowers like velvety lion's ear (Leonotis leonurus) for a different effect. It is also pretty with silver foliage (especially Plectranthus argentatus) or the cerise leaves of Iresine herbstii 'Brilliantissima'.
This salvia can be part of an almost Mediterranean look if grown with rosemary and lavender. It also combines well with ornamental grasses. It does creep about a bit, so it needs to be dug up every so often if it spreads too far but it is not an invasive salvia. Two cultivars released in autumn 2008 are marketed under the names of 'Velour White' and 'Velour Pink'. Both have white calyces, and the white form has pure white inflorescences and the other has pastel pink ones. Both arose as chance seedlings from a purple Mexican sage bush in a garden in South Africa. They may not be as cold-hardy as the species, and I have found them less reliable than other cultivars of the species.
Salvia leucantha 'Santa Barbara' is a compact form of Mexican sage bush, suited to smaller areas but with the same rich flower colour, being all purple. It grows only to 60-90 cm, doesn't seem to spread as much, and can make a wonderful low hedge. Note that 'Santa Barbara' is subject to Plant Breeders Rights in Australia so cannot be propagated for sale without the appropriate licensing arrangement.