Mentha. (For Xaverio Manetti (1723-1785), botanist and director of the Botanic Garden in Florence.) MINT. Labiatae. 25 species of aromatic herbaceous perennials or occasionally annuals. Rhizomes fleshy and creeping. Stems erect, branching. Flowers small, purple, pink or white in axillary verticils often forming an interrupted spike; calyx regular or weakly 2-lipped, tubluar or campanulate, 10-13-veined with 5 or 4 subequal teeth; corolla weakly 2-lipped with 4 subequal lobes, upper lobe usually broader, often emarginate, tube shorter than calyx; stamens 4, diverging more or less equal, usually exserted but included in many hybrids. Nutlets ovoid, smooth. Eurasia, Africa.

Nearly all mints are invasive creeping plants grown for their aromatic foliage and have long been cultivated for their culinary, antiseptic and aromatic qualities. They will tolerate a large range of soils and habitats, thriving in hot, well-drained places where planty of moisture is available to them. The running fleshy rhizomes of some species, notably Mentha spicata and Mentha suaveolens, can spread yards underground, lifting paths and invading other plants if left unchecked. These can be grown in isolated borders or in areas where the rhizomes will remain hemmed in such as in the gaps of a terrace or planted in deep chimney pots plunged into the ground. For best control some Mentha species should be confined to large troughs and pots and sited on a hard surface such as a patio to ensure security of other garden contents. Mentha pulegium is a much smaller plant and thrives in moist places either in full sun or in partial shade. Mentha requienii is a tiny mat-forming plant requiring similar conditions, its existence strongly witnessed if accidentally walked on or bruised under foot. Due to its tiny size Mentha requienii is often grown as a pan plant kept in a cold frame during winter; although small, it seeds itself readily.

Mints can be easily propagated by removal of the rhizomes to be replanted before they suffer drying. Many mints are infertile and so this is the only safe method of their reproduction. Others are so prone to hybridise that seed if set is often of hybrid origin. Mentha pulegium and Mentha requienii may be propagated from seed.

Many mints are prone to attack from mildew in dry weather and from rust fungi. These, although rarely fatal, are unsightly and can be cured by spraying with a suitable fungicide.

(Mentha aquatica x Mentha spicata) PEPPERMINT. Perennial, 30-90cm, usually glabrous, occasionally hairy, often tinged red-purple. Leaves 4-9 x 1.5-4cm, ovate-lanceolate to lanceolate, petiolate, margins serrate, apex acute, usually glabrous or thinnly hairy. Inflorescence of congested verticillasters forming a terminal oblong spike; bracts lanceolate; calyx 3-4mm, tubular, the tube usually glabrous, teeth ciliate; corolla lilac-pink; stamens included. Europe. ‘Candymint’: stems tinted red; leaves sweetly fragrant. ‘Citrata’: LEMON MINT; EAU DE COLOGNE MINT: leaves aromatic, ovate, glabrous; inflorescence smaller. ‘Crispa’: to 50cm; leaves crinkled. ‘Lime Mint’: leaves scented lime. ‘Variegata’: leaves deep green mottled cream, peppermint flavour. Z3.

SPEARMINT. perennial, 30-100cm. Leaves 5-9 x 1.5-3cm, lanceolate or lanceolate-ovate, smooth or rugose, serrate with regular teeth, glabrous to densely hairy, sessile or nearly so, apex acute. Inflorescence a terminal cylindrical spike, 3-6cm long; calyx 1-3mm, campanulate, glabrous or hairy, teeth subequal; corolla lilac, pink or white. Nutlets reticulate in hairy plants, smooth in glabrous ones. S and C Europe. ‘Chewing Gum’: leaves deep mahogany, bubble gum scent. ‘Crispa’: leaves strongly curled around the margins. ‘Kentucky Colonel’: leaves large, ruffled, richly scented. Z3.

Other members of the genus Mentha are also cultivated mainly for their fragrance which can be useful in the domestic garden as this may induce a calming effect. Those species featured above are the main ones used for culinary purposes.