Herb: Japanese Mint


Latin name: Mentha arvensis piperascens


Family: Labiatae



Medicinal use of Japanese Mint:

Japanese mint, like many other members of this genus, is often used as a domestic herbal remedy, being valued especially for its essential oil which has antiseptic properties and a 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. The whole plant is anaesthetic, antiphlogistic, antispasmodic, antiseptic, aromatic, carminative, diaphoretic, emmenagogue, galactofuge, refrigerant, stimulant, stomachic and vasodilator. A tea made from the leaves has traditionally been used in the treatment of fevers, headaches, digestive disorders and various minor ailments. The leaves are a classical remedy for stomach cancer. The essential oil in the leaves is antiseptic, though it is toxic in large doses.

Description of the plant:



Plant:
Perennial


Height:
45 cm
(1 foot)

Flowering:
May to
October

Scent:
Scented
Perennial

Habitat of the herb:

Wet grasslands near rivers and lakes at elevations of 200 - 1100 metres in China.

Edible parts of Japanese Mint:

Leaves - raw or cooked. Used as a flavouring in salads or cooked foods, they have a strong taste of peppermint. A herb tea is made from the fresh or dried leaves. An essential oil from the plant is used as a flavouring in sweets and beverages. The leaves contain about 0.2% essential oil.

Other uses of the herb:

The plant is used as an insect repellent. 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. An essential oil is obtained from the plant. It can be used as a substitute for, or adulterant of, peppermint oil. Yields of up to 1.6% have been obtained.

Propagation of Japanese Mint:

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.

Cultivation of the herb:

Wet grasslands near rivers and lakes at elevations of 200 - 1100 metres in China.

Known hazards of Mentha arvensis piperascens:

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.

Plant information taken from the Plants For A Future.