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. The plant is sometimes colloquially called cockspur flower.
It will grow in either full sun or in any degree of 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.