Mentha diemenica aka Wild Mint

Mentha diemenica is a small plant that lives for years. It belongs to the mint family, Lamiaceae. It comes from southern and eastern Australia, including Tasmania. Its range covers New South Wales, Victoria and southeast South Australia. It grows in open woods and grasslands, often on sandy ground. Wild plants favour moist, sunny sites and grow into mountain zones. Kew places it in a subtropical climate range.

This low plant reaches about 0.3 feet [0.1 metres] tall. It spreads to about 1.6 feet [0.5 metres] wide. It is thus much wider than it is tall. PFAF lists it for garden beds and notes its scent. Plants can take some light foot traffic. The flowers have both male and female organs. Insects pollinate the flowers, and the plant draws wildlife too. The species account gives no clear season for bloom. It gives no details of fruit or leaf shape.

Grow it in moist ground, in sun or light shade. PFAF lists sand, loam and clay as soils it suits. It says plants can grow in heavy clay too. The listed soils range from slightly acid to slightly alkaline. Garden reports from Australia record survival at 19°F [−7°C]. This does not show it can take the same cold in Britain. PFAF notes that cooler summers may change how well it survives. Longer, wetter winters may do so too. How well it withstands British cold thus remains unclear, even in mild areas.

You can eat the leaves raw or cooked. They add flavour to summer drinks and can make herbal tea. PFAF scores its use as food at two out of five. It gives the same score for use as medicine. The account records uses of leaves and flowering stems as medicine. These uses relate to digestion, sweating, urine flow and menstruation. Such records describe uses but do not prove health benefits. You may pick leaves as bloom starts and dry them for storage.

The whole plant yields an essential oil. PFAF records its use as a strewing herb to repel insects. This means an herb spread on the floor. Its score for other uses is two out of five. The source does not flag this species as a weed. The supplied evidence gives no pest or disease details for this species. PFAF reports no known records of toxic effects for it. This lack of records does not prove that all preparations are safe.