Prostanthera is a genus of about 90 species which occur only in Australia. They are known generally as “mint bushes” because of the aromatic foliage of many species. As a member of the Lamiaceae, Prostanthera is related to a number of culinary herbs such as mint, thyme, oregano and sage.
Prostanthera striatiflora is an erect shrub 0.5-2 m high. The foliage is narrowly elliptical or narrowly oval in shape 10-30 mm long by 2-10 mm wide and, like many mint bushes, is highly aromatic. The flowers appear in late winter to spring in clusters towards the ends of the branches. They are white with purple striping inside the throat and are surrounded by persistent, leafy bracts.
Striped mint bush is an attractive species which is spectacular in flower. It is best suited to areas with a dry climate and can be unreliable in wetter areas. Grafting onto a Westringia fruticosa root stock may be worthwhile in such areas. It is drought and frost tolerant. It should be pruned back annually by about one third if a bushy shape is to be retained.
Propagation is easy from cuttings but seed can be slow to germinate.
Photo: Murray Fagg – Australian National Botanic Gardens