Botanical name: Mentha haplocalyx
Common name: Mentha, Field mint
Family: Lamiaceae, mint family
Part used in Chinese medicine: leaves and stems
Major Chinese medicine actions:
Disperses wind-heat, cools and clears eyes and head,
vents early-stage rashes, releases constrained Liver qi
Mentha haplocalyx is a wild species of field mint native to temperate regions of the northern hemisphere and widely cultivated in China. The plant contains a strong volatile oil comprised of primarily up to 95% menthol. It grows to 2 feet high with whorls of pale lilac flowers growing from the leaf axils, blooming in summer.
Growing and Propagation
The plant is perennial and grows best in full sun to part shade. It prefers regular watering and moisture retentive, well-drained, fertile soil. Mentha spreads rapidly and can easily become invasive if the roots are not restricted by underground barriers. In urban gardens, they are probably best planted in pots to contain growth. Though it may be grown from seed, propagation is quite easy by planting cuttings in the summer or by root division in the fall or spring.
Harvesting and Preparation
For medicinal use, Bo He is most commonly used in unprepared, dried form, though it may be dry-fried or charred to bring out certain characteristics. For the best quality herb, it should be harvested when the leaves are fresh and green. It is harvested 2 to 3 times per year, with the best quality being picked in early summer before it begins flowering, or early fall after flowering is over.