MintMentha spicata, Mentha × piperita

Mint likes coolness: a corner in partial shade, or in morning sun only, in soil that stays moist, suits it better than a scorching terrace. Near a tap, under a downpipe, on the north side of a hedge or by the edge of a pond, it thrives. But wherever it is, it must be contained: its rhizomes run underground a metre a season and cross a vegetable bed in one summer. So choose a container from the outset, or a spot enclosed by paving and a path, away from the vegetable garden. Isolate each variety, otherwise they mix.

Most practical is a large pot of 30 cm or more, a basin or a bucket with holes in the bottom, sunk into the garden leaving the rim 5 cm proud, which blocks the rhizomes without depriving the plant of moisture. Fill with a mix of half potting compost, half garden compost or garden soil, as mint is hungry. In free open ground, mark out a square with metal or rigid plastic edging driven in to 30 cm. An old washing machine drum, a salvaged tub or a deep window box also do the job perfectly.

Mints hybridise freely and sowing gives plants with an unpredictable scent: always start from a piece of rhizome or a cutting of a plant whose leaves you have tasted. Spearmint, or Moroccan mint Nanah, is the best for tea and tabbouleh; peppermint, stronger, suits herbal teas and desserts; chocolate mint and bergamot mint amuse children. A garden centre plant should be chosen dense and good and green, without orange rust under the leaves. A single variety per container, two or three containers for variety.

Mint multiplies effortlessly. In spring or summer, take a 10 cm stem tip, remove the lower leaves and stand it in a glass of water on the window: white roots appear within a week, and the cutting can be planted as soon as they reach 3 cm. A 10 cm piece of rhizome, with two or three buds, laid 3 cm deep in a pot of moist compost in March or September, gives a clump in two months. If you are set on sowing, do it in March indoors, on the surface, at 20 °C, without covering.

Plant from March to May or in September-October, one plant or piece per 30 cm container, or every 30 to 40 cm in an edged square. Bury the root ball slightly deeper than it was, firm and water generously, two litres. The rhizomes settle in within a few weeks and the first cut comes about two months later. Mulch the surface with 3 cm of compost or dried grass clippings to hold moisture. If you plant in summer, shade for the first few days and water daily. Label the container with the variety name, as they all look alike in spring.

On a balcony, mint is the most rewarding herb, provided the pot is at least 25 cm and not in full afternoon sun. Rich compost, a layer of clay pebbles at the bottom, a saucer that can stay a little damp, unlike the other herbs. Watering is almost daily in summer and a liquid organic feed every fortnight supports the cutting. Every spring, remove from the pot, throw away the exhausted centre and replant the rhizomes from the edge in fresh compost: a pot that is not renewed fills with roots and gives nothing but thin stems.

Planting mint in free open ground, in the middle of the vegetable garden, "just one little plant", is the mistake everyone makes once and regrets for ten years. The second is putting several varieties in the same container: after two seasons, the most vigorous has invaded everything and the scent has become ordinary. The third is placing it in dry, scorching sun, where it yellows and catches rust. Finally, leaving the same pot four years without division makes the clump die back from the centre. Contain, separate, water, divide: four steps, and mint is the easiest of herbs.

Mint is a plant of riverbanks and knows no such thing as too much water as long as the bottom does not stagnate. In contained open ground, water five litres per clump twice a week without rain, more in a heatwave; in a pot, every day in summer, morning or evening, until the water runs out of the bottom. A thirsty mint collapses, yellows from the bottom, loses its scent and gets covered in rust. It picks up within an hour of a copious watering, but every wilt costs it leaves. A pot standing in a saucer of damp gravel keeps cool while you are away.

Mulch the surface of the container or the square with 3 to 5 cm of compost, dried grass clippings or shredded leaves to hold moisture and feed continuously. Mint is hungry: nettle liquid diluted to 10 % every three weeks from May to August, or a liquid organic feed every fortnight in a pot, keeps the leaves broad and a good green. A handful of compost scratched in at the base each spring rounds this off. Without food, the clump becomes drawn after the first cut and the leaves shrink. Stop feeding in September so the rhizomes prepare for winter.

Cut the clump back to 5 cm above the ground at least twice in the season: a first time in June, just before flowering, when the scent is at its peak, for the big harvest for drying; a second in August to get tender shoots until October. After each cut-back, water and feed. Cut without mercy the stems that escape from the container and pull out runaway rhizomes as soon as they show. Every spring, in March, remove from the pot or dig up, throw away the woody centre and replant the vigorous pieces from the edge in fresh soil: that is the secret of a mint that is always young.

Mint rust, orange pustules under the leaves and on the stems, appears on clumps stressed by drought or too dense. Cut back to the ground, put the waste in the bin, water; if it comes back, start again from healthy cuttings in fresh soil. Aphids lodge on the young shoots and go with a jet of water or soft soap at 5 %. Caterpillars and flea beetles sometimes riddle the leaves in June, without harm. Slugs gnaw the regrowth after a cut-back: evening collection. Avoid full sun and drought, the causes of almost all its troubles.

March, division and repotting, compost, first shoots. April-May, first pickings, nettle liquid, watching for escaping rhizomes. June, big harvest for drying and cut-back before flowering. July, diligent watering, flowering on the stems left for the bees. August, second cut-back, feeding. September-October, tender pickings, cuttings in a glass of water for winter, end of feeding. November, the top growth dies; cut to the ground, mulch with dead leaves. December-February, nothing, except a pot brought in for a few fresh leaves. Mint is completely hardy and starts again from its rhizomes from mid-March.

Pick from May until the first frosts, in the morning in dry weather, pinching the stem tips above a pair of leaves, which makes the plant branch. The leaves are most fragrant just before flowering. In winter, mint disappears completely below ground and needs no protection at all, even at -15 °C; a pot stays outside, against a wall. For fresh leaves in December, bring in during October a few rooted cuttings or a small piece of rhizome in a 15 cm pot, on a bright, cool window, at 15 °C: they give modestly until February, then go back to the garden.