Spearmint, also known as garden mint, common mint, lamb mint and mackerel mint, is a species of mint, Mentha spicata, native to Europe and southern temperate Asia, extending from France in the west to southern China in the east. It is naturalized in many other temperate parts of the world, including northern and southern Africa, North America and South America. It is used as a flavouring in food and herbal teas. The aromatic oil, called oil of spearmint, is also used as a flavoring and sometimes as a scent.
The species and its subspecies have many synonyms, including Mentha crispa, Mentha crispata and Mentha viridis.
The most abundant compound in spearmint oil is R-(–)-carvone, which gives spearmint its distinctive smell. Spearmint oil also contains significant amounts of limonene, dihydrocarvone, and 1,8-cineol. Unlike oil of peppermint, oil of spearmint contains minimal amounts of menthol and menthone. It is used as a flavouring for toothpaste and confectionery, and is sometimes added to shampoos and soaps.
Spearmint essential oil has had success as a larvicide against mosquitoes. Using spearmint as a larvicide would be a greener alternative to synthetic insecticides due to their toxicity and negative effect to the environment.
Used as a fumigant, spearmint essential oil is an effective insecticide against adult moths.