Mint Bush
Prostanthera rotundifolia
Family: Lamiaceae or Labiatae
What it is like
Prostanthera rotundifolia is an evergreen Shrub growing to 4.5 m (14ft) by 3 m (9ft). See above for USDA hardiness. It is hardy to UK zone 9 and is frost tender. It is in flower in May. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils. It cannot grow in the shade. It prefers moist soil.
Height (m): 4.5
Where it is found
Sheltered hillsides, usually in sylvan habitats. Sandy soils over sandstone on rainforest edges and sheltered spots in sclerophyll forest.
Australia - New South Wales, Queensland, Tasmania, Victoria.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 2
The plant is rich in volatile oils, including menthol and cineole (as found in the mints, Mentha spp.). The leaves are antibacterial, antifungal and carminative. They are used externally in the treatment of colds and headaches. Presumably the leaves are infused in a bowl of hot water and the vapour inhaled.
Antibacterial: Kills bacteria.
Antifungal: An agent that inhibits or destroys fungi. Used in the treatment of various fungal problems such as candida.
Carminative: Reduces flatulence and expels gas from the intestines.
Other
Rating: 2
An essential oil obtained from the leaves is medicinal. The leaves yield up to 0.7% of the oil. The dried leaves are used in pot-pourri.
Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.
Pot-pourri: Aromatic plants used to impart a pleasant smell to an area. Can this be grouped with incense or essential oil?
Scented Plants: Plants noted for their scent
How it is grown
Requires a sunny position in a well drained soil and does not thrive on shallow chalky soils. Prefers a humus-rich lime-free soil. This species only succeeds outdoors in the mildest areas of the country. It is hardy to at least -7°c in Australian gardens though this cannot be translated directly to British gardens due to our cooler summers and longer colder and wetter winters. It does succeed outdoors in various places in Cornwall, though it is probably best on a wall even there. A short-lived plant, but it can be grafted onto the roots of Westringia fruticosa which allows it to be grown in less favourable conditions and also probably increases its life span. Plants are very tolerant of light trimming, but dislike hard pruning. Any trimming is best carried out immediately after flowering. Both leaves and flowers have a minty aroma.
Propagating it: Seed - sow spring in a greenhouse.The seed usually germinates within a few weeks. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. The seed remains viable for 2 - 3 years in normal storage. Cuttings of soft-wood in early summer in a frame. They root readily. Cuttings of half-ripe wood, July/August in a frame.
Best place to grow: Woodland Garden Sunny Edge;
Habit: Shrub
Hardiness: 8-11
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist