There are many fascinating plants in the sage family. As garden plants, some may be more interesting than beautiful, but Salvia muirii, with its large intense blue flowers throughout summer, performs to perfection. This beautiful plant is easy to grow in a pot, rockery or garden bed. Finding Salvia muirii in the veld however is not so easy, for the natural populations are restricted to only a few localities in the southern Cape. Here they grow in dry fynbos in sandy soils along a narrow strip following the northern foothills of the Langeberg near Riversdale to the Great Brak River near Mossel Bay. The first collection of plants of Salvia muirii was made in 1915 by Dr John Muir, an enthusiastic plant collector who lived in the southern Cape and who contributed greatly to our knowledge of the plants of this area

Salvia muirii is a small, twiggy, evergreen shrub that grows only about 30 cm high. It has a woody stem and an underground rootstock that gives it the ability to resprout easily after fires. The leaves are leathery, oval in shape and light green to almost grey in colour. When crushed, they are slightly sticky and release a light scent that is reminiscent of Vicks.

The flowers appear from mid-summer until autumn (December-March), opening in pairs at the tip of each stem. The stems continue to grow forming new buds, while the older flowers fall off and only their dark red bracts remain. The flowers, which are quite large for such a small plant, are blue with a characteristic white mark on the lower lip. The flower shape is typical of Salvia, with the upper lip hooded or closed while the lower lip opens wide and flat. The small black spherical seeds sit deep inside the remaining flower bracts and are released about a month after flowering, when the bracts are dry.

Growing Salvia muirii

Salvia muirii is a delight to have in the garden, particularly during summer when it is covered with flowers. This little woody shrub is also long-lived, drought resistant and almost pest free. It is easy to grow with the most important requirements being full sun and well-drained soil. To encourage compact bushy growth it should be pruned lightly throughout the year and fed regularly with an organic fertilizer. Like so many other salvias, Salvia muirii is popular with bees in the garden. At Kirstenbosch we grow a particularly dark blue form of Salvia muirii that will be released soon as a special selection. This good form of Salvia muirii was collected and introduced into horticulture by Ernst van Jaarsveld, a great plantsman with a particular interest in salvias.

New plants of Salvia muirii can be propagated from cuttings or seed. The best time to make cuttings is in spring or summer, using the fresh, new growth. The plants also produce plenty of seed that is best sown during autumn or winter. The seed germinates within about 10 days and produces strong, vigorous seedlings that often flower in their first year.

In South Africa there are more than thirty species of Salvia. Worldwide there are between 800 and 900 species, widely distributed throughout the temperate and tropical regions of the northern and southern hemispheres. The best-known salvia is sage, Salvia officinalis, from the Mediterranean, which has been used since ancient times as a powerful healing plant and strong culinary herb. The name salvia comes from the Latin salvere, which means to be in good health, to cure and to save.

References

• Bremness, Lesley, 1988, The Complete Book of Herbs, Dorling Kiendersley Book
• van Jaarsveld, Ernst, Salvia muirii-'n Nuwe Blou Salie, Veld en Flora, December 1983
• Flora of Southern Africa, 1985, Volume 28 Part 4

Liesl van der Walt
Kirstenbosch National Botanical Garden
February 2002