Mentha is also known as mint. The genus has a sub cosmopolitan distribution across Europe, Africa, Asia, Australia, and North America, The species that makes up the genus Mentha are widely distributed and can be found in many environments. WIdely used species in India is Mentha piperita.
Most grow best in wet environments and moist soils. Mints grow 10–120 cm tall and can spread over an indeterminate area. Due to their tendency to spread unchecked, some mints are considered invasive.
Mints are aromatic, almost exclusively perennial herbs. They have wide-spreading underground and over ground stolon’s and erect, square, branched stems. The leaves are arranged in opposite pairs, from oblong to lanceolate, often downy, and with a serrated margin. Leaf colours range from dark green and grey-green to purple, blue, and sometimes pale yellow, The flowers are white to purple and are produced in false whorls called verticillate. The corolla is two-lipped with four subequal lobes, the upper lobe usually the largest. The fruit is a nutlet, containing one to four seeds.
Mentha is a member of the tribe Mentha in the subfamily Nepetoideae. The tribe contains about 65 genera, and relationships within it remain obscure. Authors have disagreed on the circumscription of Mentha. For example, M. cervina has been placed in Pulegium and Preslia, and M. cunninghamii has been placed in Micromeria. In 2004, a molecular phylogenetic study indicated that both M. cervina and M. cunninghamii should be included in Mentha. However, M. cunninghamii was excluded in a 2007 treatment of the genus.
More than 3,000 names have been published in the genus Mentha, at ranks from species to forms, the majority of which are regarded as synonyms or illegitimate names. The taxonomy of the genus is made difficult because many species hybridize readily, or are themselves derived from possibly ancient hybridization events. Seeds from hybrids give rise to variable offspring, which may spread through vegetative propagation. The variability has led to what has been described as "paroxysms of species and subspecific taxa"; for example, one taxonomist published 434 new mint taxa for central Europe alone between 1911 and 1916. Recent sources recognize between 18 and 24 species.
In India, it is largely confined to North India in the States of Uttar Pradesh, Punjab and Haryana. Temperate to tropical climate is suited for plant growth. Sunny weather with moderate rain is conducive to its luxuriant growth. A deep soil, rich in humus which can retain moisture, is suitable for mint cultivation.
All mints thrive near pools of water, lakes, rivers, and cool moist spots in partial shade. In general, mints tolerate a wide range of conditions, and can also be grown in full sun. Mint grows all year round. They are fast-growing, extending their reach along surfaces through a network of runners.
Due to their speedy growth, one plant of each desired mint, along with a little care, will provide more than enough mint for home use. Some mint species are more invasive than others. Even with the less invasive mints, care should be taken when mixing any mint with any other plants, lest the mint take over. To control mints in an open environment, they should be planted in deep, bottomless containers sunk in the ground, or planted above ground in tubs and barrels.
Some mints can be propagated by seed, but growth from seed can be an unreliable method for raising mint for two reasons: mint seeds are highly variable one might not end up with what one supposed was planted and some mint varieties are sterile. It is more effective to take and plant cuttings from the runners of healthy mints.
The most common and popular mints for commercial cultivation are peppermint (Mentha piperita), native spearmint (Mentha spicata), Scotch spearmint (Mentha gracilise), and corn mint (Mentha arvensis) also (more recently) apple mint (Mentha suaveolens).
Mints are supposed to make good companion plants, repelling pests and attracting beneficial ones.
They are susceptible to whitefly and aphids. Harvesting of mint leaves can be done at any time. Fresh leaves should be used immediately or stored up to a few days in plastic bags in a refrigerator. Optionally, leaves can be frozen in ice cube trays. Dried mint leaves should be stored in an airtight container placed in a cool, dark, dry area.
References : Wikipedia, Spices Board, Divya Pharma, Aaj Tak, Google search & self-study
Written by : Roshan Vasantrao Pawar, Student - Indira Gandhi National Open University, Delhi, Department of Social Work