The name of this Australian native Plectranthus is something of a mystery: it seems likely that it is P. parviflorus, P. graveolens or P. suaveolens. I refer to it as Plectranthus parviflorus but am happy to be corrected! These plants are apparently hard to tell apart by non-botanists! Mine was given to me by a friend as being one of the toughest plants she had ever grown. It gets to about 40 cm tall and forms a mound. It seems that the name Plectranthus australis may be a synonym for Plectranthus parviflorus.
It will grow in either full sun or full shade, plus in any moisture position ranging from completely dry spot or a bog! It has aromatic, hairy leaves and seems to be covered in dainty spires of purple-blue flowers basically all year round. I enjoy seeing its haze of lovely flowers juxtaposed with the lime-green bracts of Euphorbia corallioides in a shaded part of my garden in mid-spring, when it seems at is most floriferous. Elsewhere in the garden, it consorts prettily with a lilac-pink Pentas throughout summer and autumn. It also looks effective growing beneath other Plectranthus species, such as Plectranthus ecklonii. It is an excellent groundcover under a tree, as pictured at left. It will self-seed where it is happy!
There is a lovely form with white-variegated leaves that is sold as P. parviflorus 'Blue Spires', which is similarly as forbearing of a range of conditions as the green-leaved version. The plants look good in a native Australian-style garden, a woodland area or a flowery border. Plectranthus parviflorus can be susceptible to the attack of flea beetles, which disfigure the foliage. Neem oil can be tried as a control.