Herbs
Mint
Mentha × piperita
Timings for your region
Suggested: Moderate · Explained in the glossary
Never sown — young plants go straight into the bed.
Plantingmid April – mid June
Harvestmid May – mid October
Practical tip
Only ever plant it with a root barrier or in a pot — its runners will otherwise take over the whole bed within two years.
Origin & history
Peppermint is not a wild species but a natural cross between water mint and spearmint, spotted in England around 1696 and afterwards grown as a field crop at Mitcham south of London — “Mitcham” still stands for peppermint today. Being a hybrid it is sterile and sets no viable seed, so every peppermint plant in the world comes from vegetative propagation. The rest of the genus, by contrast, crosses readily, which explains the many intermediate forms in the trade.
Varieties
“Mint” is an umbrella term for dozens of species and varieties. For tea and for Middle Eastern cooking you want spearmint or Moroccan mint (Mentha spicata) — mild and sweetish, without the menthol bite; peppermint is the sharp, cooling one. Then there are the scented varieties such as chocolate, strawberry or orange mint. Buy plants, and buy by smell: rub a leaf, because mint labels are notoriously unreliable, and a seed packet marked “peppermint” will necessarily give you something else.
Care
Mint is the one kitchen herb that does not want to stand dry: evenly moist, in partial shade, and in a pot watered almost daily in summer. As soon as the first flower buds appear, cut the whole stand back to a hand’s width — the second flush gives large, soft leaves again, whereas flowering shoots give only small tough ones. In a pot or behind a root barrier the soil exhausts itself quickly; divide the clump every two or three years, discard the spent middle and replant the strong outer pieces in fresh soil.
What can go wrong
Mint rust is the classic: orange-brown pustules on the undersides of the leaves that spread fast in summer. The fungus overwinters in the rootstock, so cut affected shoots right off and put them in the household waste rather than the compost, plant more airily, water at the base rather than over the foliage — and if the attack keeps coming back, start again with healthy young plants in a new spot. Dense old clumps add powdery mildew towards the end of summer; a radical cutback usually deals with both. A pot that is too small is the second commonest reason for small, tough leaves.
Harvest, storage & kitchen
Mint has most flavour just before flowering; cut whole shoots then instead of picking individual leaves. It is one of the few herbs that loses almost nothing when dried — dry it in bunches somewhere airy and shaded and keep it dark in a well-sealed jar. Fresh spearmint suits yoghurt, peas, potatoes, couscous and cold drinks; sharp peppermint is usually too dominant for that and is better kept for tea.
All timings are guide values for the given climate, not a guarantee. Weather, aspect and variety all have a say.