Know your herbs: Mint

There are hundreds of varieties of mint plants, but these are some of our favourites:

Spearmint has pointed spikes of lavender flowers but is very variable in terms of its foliage and flavour. Two of the best for flavour are 'Moroccan' and 'Tashkent'.

Peppermint is a sterile hybrid of water mint and spearmint. There are two main kinds: black peppermint with dark green, purple-flushed foliage and rounded flower spikes; and white peppermint, with bright green leaves and a spearmint-like inflorescence.

Bergamot or eau-de-cologne mint has a lavender-like perfume. Variants of this form, which more closely resembles water mint than spearmint, include 'Basil', 'Chocolate', and 'Grapefruit'.

Gingermint has attractive yellow-marbled leaves and a subtle spicy flavour.

Applemint is a larger plant, growing up to 1m, with downy leaves and tapering spikes of pink to white flowers. 

Woolly or Bowles' mint is a vigorous, tall-growing, sterile hybrid with broadly oval furred leaves and pointed clusters of lavender flowers. This fine flavour is prized for making mint sauce.

Corsican mint forms dense, moss-like mats of tiny, powerfully mint-scented leaves, which are peppered with minute lavender flowers in summer. It is frost-hardy and best suited to cultivation in large shallow pots in a damp shady corner.

Mints are indispensable herbs but as garden plants, most are very invasive.

The answer is to grow them in large pots, or plant them in containers—an old bucket will do—that can be buried in the ground. They will still try to escape, but are much easier to control if confined.

Variegated mints are very ornamental and, suitably containerised, can be put to good use as 'gap fillers' in flower borders and as focal points in damp shady corners where little else will grow.

The ideal conditions for growing mint are moist, rich soil and half to full sun.

Propagate mints from cuttings or by dividing clumps. Pennyroyal, Corsican mint and American pennyroyal are often grown from seed.

Maintenance mints are rich feeders, so container-grown plants should be lifted in winter and divided. Replant a proportion of the strongest rhizomes in fresh compost, adding some slow-release fertiliser or well-rotted compost.

Some mints are prone to a rust disease, called puccinea menthae. Infected plants should be burnt and the area no longer used for mint. To prevent rust, divide and feed plants regularly.

Mints should be harvested and stored to dry in a warm, airy place away from direct sunlight. Store crumbled leaves in an airtight container. Harvest foliage to use fresh as required.

Both peppermint and pennyroyal are insect repellents.

Sprinkle cotton-wool balls with peppermint essential oil and leave them where rodents enter.

Add a few drops of peppermint essential oil to a damp rag and wipe over benches and cupboard interiors to deter ants and cockroaches.

Make a personal insect repellent: mix 1 part lavender, 1 part eucalyptus, 1 part peppermint essential oils with 3 parts unscented moisturiser or sweet almond oil, and rub into the skin.

To deter fleas, put dried pennyroyal under pet bedding or put a spot of oil on its collar. Don't use pennyroyal on cats or pregnant dogs, as it is toxic to them.

Peppermint relaxes the gut and can help to relieve indigestion, nausea, wind and cramping.

Clinical trials have verified its therapeutic effects on many symptoms of irritable bowel syndrome, including diarrhoea, constipation, bloating and abdominal pain, especially when taken in the form of enteric-coated peppermint oil capsules.

Topically, peppermint essential oil can alleviate joint and muscle pain and headaches. When inhaled, it can also help to reduce feelings of nausea and act as a nasal decongestant.

Do not use peppermint in greater than culinary quantities, and do not use the essential oil if you are pregnant or breastfeeding.

Fresh mint can overwhelm other flavours due to its slightly anaesthetic effect on the taste buds. It does not complement other herbs well and is best used with a light hand.

Dried mint is less assertive and is favoured in eastern Mediterranean and Arab countries. Spearmint, or garden mint, is the most commonly used. It is a classic flavouring with roast lamb, and also goes well with potatoes, peas, salads and yoghurt-based dishes, such as Indian raita and Greek tzatziki.

Spearmint is often included in herb tea blends. Peppermint is popular after meals as a digestive tea. Both kinds are used to flavour chewing gum but peppermint is much nicer in ice cream, confectionery and liqueurs.