Peppermint

Peppermint: how do you recognise it?

Habit

Upright, branching stems 40–60 cm tall, spreading quickly by runners.

Leaves

Opposite, lance-shaped and toothed, dark green, often flushed purple.

Stems

Square, as in all members of the mint family, and often reddish purple.

Scent

Strong and fresh, of menthol, as soon as you rub a leaf.

Flowers

Narrow, lilac flower spikes at the shoot tips, from July to September.

Roots

Shallow rhizomes and runners that spread quickly.

Flowering: July–September · Harvest and fruit: June–September · Plants: March–May and September · Pruning: March and September

Why grow it?

• The best-known mint flavour: fresh or dried for tea, desserts, sauces and drinks.
• Grows fast and gives fresh leaves from spring to autumn.
• Its lilac flower spikes attract bees, hoverflies and butterflies in summer.
• Fully hardy and easy: it comes back every spring.
• Also does well in a pot on the patio.

Peppermint: where does it grow best?

• Sun or partial shade. In full sun, though, the soil must stay moist.
• Fertile, moisture-retentive soil: sand, loam or clay, acid to chalky.
• Moist to wet: it likes soil that does not dry out.
• Always in a confined space: a bottomless bucket, a trough or a pot.
• One plant is usually enough for a family: it soon fills 50–60 cm.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal or wet

Size

0.6 m tall, 0.6 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Chives: Another culinary herb that copes with moist soil.
• Parsley: Together the basis of a herb trough by the kitchen.
• Lovage: A tall, hardy culinary herb for the same moist, fertile soil.
• Lemon balm: Another fresh herb for tea, best kept in its own pot too.

Peppermint: when and how to plant it?

Plant in March–May and September.

1. Plant in March–May or in September.
2. Sink a large bucket or container without a bottom into the ground, with the rim 3–5 cm above soil level, so the runners cannot creep over it.
3. Fill it with garden soil mixed with compost and set the plant at the same depth as it was in the pot.
4. For a pot on the patio, use ordinary potting compost and a pot with a drainage hole.
5. Water in well straight away and keep the soil moist for the first few weeks.

Care

Water

Keep the soil moist, especially in pots and during dry summers.

Feeding

A layer of compost in spring. Give pots some organic fertiliser now and then in summer.

Harvesting

Snip 10 cm shoot tips regularly: it stays compact and keeps producing fresh leaves. The flavour is strongest just before flowering.

Runners

Check every spring that no runners have crept over the rim of the bucket, and pull them out.

Renewing

Every two or three years, lift it, divide it and replant the youngest part in fresh soil.

Tip: Leave the rim of the bucket a few centimetres above the ground and check around it every spring: otherwise surface runners simply creep over the edge. Pick often, because the more you harvest, the fresher the leaves.

Peppermint: when to prune it?

Pruning months: March and September.

When: After flowering, in September, and in March remove last year’s dead stems.

How:

• After flowering, cut all the stems back to a few centimetres above the ground: it soon regrows with fresh leaves.
• In March, cut away the dead stems, just before the new leaves appear.
• Cut stems with rust down to the ground as soon as you see them.

Caution: Do not put stems with mint rust on the compost heap: that way you avoid spreading the fungus.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In May–August: snip 10 cm shoot tips, strip the lower leaves and stand them in a glass of water or in moist cutting compost. Roots appear within one to two weeks.

Division

In March–April or in September, cut off a piece of rhizome with runners and shoots and plant it separately.

Seed

Not possible: peppermint rarely sets viable seed, and seed sold as peppermint does not give true peppermint.

Peppermint: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy, to about −25 °C: no protection needed.
• It dies back above ground and sprouts again from the rhizomes in spring.
• Stand a pot against a wall: roots in a pot are more vulnerable to frost.
• For fresh leaves in winter, pot up a piece of rhizome in autumn and keep it on a cool, bright windowsill.

Diseases and pests

• Mint rust: Orange to brown pustules on the stems and the undersides of the leaves. Cut affected stems down to the ground and do not compost them.
• Powdery mildew: White powder on the leaves, especially in dry summers. Water at the base, cut back affected stems and give the plants some space.
• Leaf beetles: Small, shiny green beetles that eat little holes in the leaves. Pick them off or shake them out of the plant into a bucket.
• Spreading: Left unchecked, it quickly overruns the rest of the garden. Always plant it in a bottomless bucket or a pot.

Through the year

• March: Cut away dead stems. Add compost. Plant or divide.
• April: Plant. Pull out runners outside the bucket.
• May: Harvest. Take cuttings.
• June: Harvest freely. Water in dry spells.
• July: Flowering, full of bees and butterflies. Pick just before flowering.
• August: Flowering. Watch for rust.
• September: Cut back after flowering. Plant or divide.
• October: Pot up a piece of rhizome for the windowsill.
• November: The plant dies back above ground.

Edible and useful

Leaves (June–September)

Cut the stems in June and July just before flowering, when the menthol content is highest; after this first cut the plant regrows for a second harvest in August–September. Pick on a dry, sunny morning. Peppermint is sharper and cooler than spearmint: mainly for tea, in chocolate puddings and in liqueur.

Storing

Dry the stems in small bunches, hung upside down somewhere airy and dark, until the leaves rustle. Then strip them off and store them whole in a closed jar in the dark, where they keep their aroma for a year. Fresh stems keep for a few days in a glass of water.

Caution: Peppermint tea is safe for most people but can make heartburn worse. Do not give peppermint (and certainly not peppermint oil) to babies and young children: menthol can affect their breathing. Never swallow undiluted peppermint essential oil. Peppermint spreads: grow it in a pot or a bottomless container. Do not confuse it with pennyroyal (Mentha pulegium), which is poisonous.

Eating and using is at your own risk: see the terms of use.

Recipes

• Home-grown peppermint tea (Tea · 1 cup · 5 min + drying)
• Peppermint liqueur (Liqueur · ± 750 ml · 15 min + 2 weeks steeping)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Its cool, fresh taste comes from menthol, a substance that triggers the cold sensors in your mouth without actually lowering the temperature.
• Peppermint hardly ever sets viable seed: true peppermint is always propagated vegetatively, from cuttings or rhizomes.
• Mitcham, now part of London, was famous in the 18th and 19th centuries for its peppermint fields. The name lives on in the black peppermint ‘Black Mitcham’.