Everyone knows mint as a flavour and can probably recognise the common mint plant. But there’s much more to the group of plants called mints, including some interesting natives. Growing Mints: A Short Guide.
They’re all in the family Lamiaceae, which is called the mint family but includes diverse plants such as salvias, lavenders and basil. True mints are in the genus Mentha, with 25-30 species including common mint (M. spicata) and peppermint (M. x piperita). Spearmint is similar to common mint but has pointier leaves. Others with distinctive aromas and flavours are apple mint, eau-de-cologne mint, basil mint, lemon mint, chocolate mint and pineapple mint. Two have tiny leaves and are excellent groundcovers between stepping stones – Corsican mint (M. requienii) and pennyroyal (M. pulegium).
The oil glands in mint leaves contain menthol, which has cooling, anaesthetic, antiseptic and decongestant properties.
A flowering eau-de-cologne mint
All Mentha species produce runners that spread outwards, putting down roots as they go – potentially being a nuisance. If growing common mint, use a root barrier to corral it or keep it in a large pot. It likes rich soil with plenty of moisture and mild temperatures, growing strongly in spring and summer, then dying back according to how cold the winter is. In hot
Pineapple Mint
climates it prefers a shady spot.
To substitute with a native species, try river mint (M. australis), widely found around rivers and other damp, shaded spots. It grows 30cm high and a metre wide. Bush mint (M. satureioides) is sweetest through the cooler months and grows 20cm high and 40cm wide in most frost-free areas.
Corsican mint
Plenty of other plants have mint in their common name. Dr Trevor Wilson, research scientist at the Royal Botanic Garden Sydney, specialises in the mint family Lamiaceae, especially native Prostanthera and Coleus species. Prostanthera has more than 100 species that have highly aromatic leaves and profuse, typically mauve or white flowers; they’re popular shrubs in home gardens and some are edible. The Coleus genus includes what were called Plectranthus until all Australian species were reclassified recently. Wilson knows of 63 species but is discovering more on his
collecting trips around Australia. He observes that most have hairy or furry leaves,
Apple Mint
“The volatile oils are held in glands and hairs on the leaves and stems,” Wilson explains. Some smell pleasant, such as Coleus bellus from far north Queensland. “Exactly like lemon drops,” he says. He also likes C. suaveolens from northern NSW, which has fruitier notes. These both contain cineole, giving the lemon aroma, in their complex oil chemistry.
Wilson is less complimentary about bush basil or five-spice plant (C. graveolens), said to be a mix of mint, basil and sage; he says “some populations have a weird fetid smell”. Importantly, the volatile oils in our native species have potential pharmaceutical uses, like various species from other continents.
