Mentha longifolia: Australian Growing Guide

Mentha longifolia (Horsemint) is a Perennial which grows to a height of 1m and a width of 1m . It has a hardness rating of 6 and is vulnerable to frost.

Horsemint will flower in February to March. the seeds ripen from March to April

The flowers from this plant are hermaphrodite (has both male and female organs) and they are pollinated by Insects.

How to Grow Mentha longifolia

Soil Information

Horsemint will grow in light (sandy),medium (loamy),hard (clay) soil. It is not necessary for the soil to be well drained.

The soil prefers the following PH / acid levels :

• pH of less than 6, Acidic soils
• pH between 6 and 8, Neutral soils
• pH greater than 8, Basic soils

Horsemint prefers moist soils

Ideal Planting Locations

Horsemint can grow in semi or areas with no shade.

Waste places and damp roadsides.

Planting places suited to this plant described below.

• Grows within a woodland garden
• Grows on a sunny edge
• Works within dappled Shade
• Grows in a shady edge
• Can be planted in Cultivated Beds

Mentha longifolia Cultivation Details

An easily grown plant, it succeeds in most soils and situations so long as the soil is not too dry. Grows well in heavy clay soils. A sunny position is best for production of essential oils, but the plants also succeed in partial shade.

There is some confusion over the name of this plant, it appears in the British flora but according to Flora Europaea it is not found in Britain. Sometimes cultivated for its leaves, there are some named varieties.

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 keep them free of insect pests. Members of this genus are rarely if ever troubled by browsing deer.

Edible Uses*

* See disclaimer

Edible Rating: 2/5

Leaves - raw or cooked. Peppermint-scented, they are used as a flavouring in salads, chutneys and cooked foods. A herbal tea is made from the leaves. An essential oil obtained from the leaves and flowering tops is used as a food flavouring in sweets etc. A peppermint-like taste.

• Condiment - the various plants that are used as flavourings, either as herbs, spices or condiments.
• Leaves -
• Tea - the various herb teas that can be used in place of tea, plus the genuine article.

Mentha longifolia Medicinal Uses*

* See disclaimer

Medicinal Rating: 2/5

Horsemint, like many other members of this genus, is often used as a domestic herbal remedy, being valued especially for its antiseptic properties and its beneficial effect on digestion. Like other members of the genus, it is best not used by pregnant women because large doses can cause an abortion.

The leaves and flowering stems are antiasthmatic, antispasmodic, carminative and stimulant. Tea made from the leaves 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.

• Antiasthmatic - Treats asthma.
• Antiseptic - Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of microorganisms.
• Antispasmodic - Relaxes muscle spasms and cramps, calming nervous irritation.
• Carminative - Reduces flatulence and expels gas from the intestines.
• Stimulant - Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Mentha longifolia Propagation

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 directly into their permanent positions. However, for maximum increase it is possible to divide the roots up into sections no more than 3 cm 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.

Scented parts of the plant

Plant: Crushed/Dried

Known Hazards

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.

Other Mentha longifolia Uses

The leaves contain about 0.57% essential oil. It is sometimes used as a substitute for peppermint oil in confectionery. 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.

• 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.

References

Flora of the British Isles.

• Clapham, Tootin and Warburg.
• Author: Clapham, Tootin and Warburg.
• Publisher: A very comprehensive flora, the standard reference book but it has no pictures.
• Date of Publication: 1962