Mentha australis
Family: Lamiaceae or Labiatae
What it is like
Mentha australis is a PERENNIAL growing to 0.5 m (1ft 8in). It is not frost tender. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 0.5
Where it is found
Along streams, usually in semi-shade, in inland areas.
Australia - New South Wales, Victoria.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 2
Like many other members of this genus, this species is often used as a domestic herbal remedy, being valued especially for its antiseptic properties and its beneficial effect on the digestion. Like other members of the genus, it is best not used by pregnant women because large doses can cause an abortion. A tea made from the leaves of most mint species has traditionally been used in the treatment of fevers, headaches, digestive disorders and various minor ailments. The leaves are harvested as the plant comes into flower and can be dried for later use. The essential oil in the leaves is antiseptic, though it is toxic in large doses and can cause abortions.
Abortifacient: Causes an abortion.
Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.
Carminative: Reduces flatulence and expels gas from the intestines.
Febrifuge: Reduces fevers.
Other
Rating:
The leaves contain about 0.2% of an essential oil. It is a coarse peppermint. Rats and mice intensely dislike the smell of mint. The plant was therefore used in homes as a strewing herb and has also been spread in granaries to keep the rodents off the grain.
Companion: Companion planting is the careful placement of plants (especially vegetables and herbs) which have been shown to have beneficial effects on one another.
Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Strewing: Plants, usually aromatic, that are strewn on the floor to give a nice smell, repel insects etc.
Attracts Wildlife: Plants noted for attracting wildlife
Scented Plants: Plants noted for their scent
How it is grown
We do not have much information on this species and do not know if it will be hardy in Britain. The following notes are based on the general needs of the genus. Succeeds in most soils and situations so long as the soil is not too dry. Prefers a slightly acid soil. Grows well in heavy clay soils. A sunny position is best for production of essential oils, but succeeds in partial shade. Most mints have fairly aggressive spreading roots and, unless you have the space to let them roam, they need to be restrained by some means such as planting them in containers that are buried in the soil. Hybridizes freely with other members of this genus. The whole plant has a mint-like aroma. The flowers are very attractive to bees and butterflies. A good companion plant for growing near cabbages and tomatoes, helping to deter pests. Members of this genus are rarely if ever troubled by browsing deer.
Propagating it: Seed - sow spring in a cold frame. Germination is usually fairly quick. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer. Mentha species are very prone to hybridisation and so the seed cannot be relied on to breed true. Even without hybridisation, seedlings will not be uniform and so the content of medicinal oils etc will vary. When growing plants with a particular aroma it is best to propagate them by division. Division can be easily carried out at almost any time of the year, though it is probably best done in the spring or autumn to allow the plant to establish more quickly. Virtually any part of the root is capable of growing into a new plant. Larger divisions can be planted out direct into their permanent positions. However, for maximum increase it is possible to divide the roots up into sections no more than 3cm long and pot these up in light shade in a cold frame. They will quickly become established and can be planted out in the summer.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge;
Habit: Perennial
Hardiness:
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
Although no records of toxicity have been seen for this species, large quantities of some members of this genus, especially when taken in the form of the extracted essential oil, can cause abortions so some caution is advised.