South Africa has a plethora of very attractive indigenous plants. Rock sage is definitely on that list with its dense purple flower spikes creating impressive displays in autumn through winter. Besides brightening up your winter garden, due to its semi-succulent nature, it is excellent for those hot and sunny spots.
A quick look at Rock Sage:
Latin Name | Thorncroftia succulenta
Common Names | Rock Sage, Klipsalie
Family | Lamiaceae
Rock Sage grows naturally in the Limpopo and Mpumalanga provinces of South Africa. It's actually classified as a succulent because of its leaves and their capability of water retention- hence its species name 'succulenta'. The plant, however, looks more like a herbaceous shrub and grows into a bush that can reach up to 1m in height.
There are numerous stems that branch out and when young have smooth hairs. The leaves are grey/green in colour and are obovate in shape. Thorncroftia succulenta flowers in late summer and early autumn. The flowers can be mauve or lilac and are tubular in shape congregating in spikey bunches.
The succulent nature of the Rock Sage allows it to grow in sandy spaces or crevices and it can survive through relatively long periods of drought. The fact that it's evergreen is also great because it provides year-long foliage and looks great in rockeries.
Growing Rock Sage
Thorncroftia succulenta can be planted in sunny areas of your garden. Make sure it has well-drained soil and plant it amongst rocks or boulders to retain heat and simulate a subtropical temperature. You can propagate Rock Sage by taking cuttings and rooting them in sand. If you're growing them from seed, sow them in September/October and they should germinate within 2 - 4 weeks.