How to Grow Mint in Containers: Complete UK Beginner’s Guide

Mint is one of the most satisfying herbs to grow in the UK — it thrives in our cool, moist climate, grows back reliably year after year, and rewards even the most hands-off gardener with an abundant harvest. The catch? Mint is an aggressive spreader. Left in open ground it will colonise your entire bed within a season. The solution every experienced UK gardener uses is simple: keep it in a container.

This guide covers everything a beginner needs to know, from choosing varieties and pots through to harvesting, problem-solving and getting your mint safely through winter.

Why You Should Always Grow Mint in Containers

Mint spreads through underground stems called stolons (or runners). A single plant can extend 60 cm or more in a single growing season, popping up new shoots wherever a stolon reaches. In open ground, this means mint quickly crowds out neighbouring plants and becomes almost impossible to eradicate.

Growing mint in containers solves this completely. The pot walls act as a physical barrier, keeping roots — and the plant — exactly where you want them. You get the fresh harvest without the takeover.

There is a secondary benefit too: pots let you position mint precisely. A container by the back door means fresh leaves within arm’s reach every time you’re cooking. On a sunny windowsill, a small pot keeps mint available all year with minimal effort.

Mint is far from the only herb that does well in containers. See our guide to the best herbs to grow in containers for ideas on building a productive patio herb garden around your mint.

Choosing the Right Mint Variety

The Mentha genus contains dozens of species and hundreds of cultivars. Most of them will thrive in UK conditions; the choice comes down to flavour, fragrance and what you plan to use your harvest for.

Spearmint (Mentha spicata)

The classic kitchen mint and the one most commonly found in supermarket bunches. It has bright green, crinkled leaves with a clean, sweet flavour that works beautifully in mint sauce, new potatoes, and summer drinks. It is vigorous and easy to grow — a sensible first choice for beginners.

Peppermint (Mentha × piperita)

A natural hybrid with a stronger, more intense menthol hit. Use it in herbal teas, chocolate desserts or homemade cordials. The leaves are slightly darker than spearmint and the plant can reach up to 90 cm in the ground, so choose a deeper container.

Moroccan Mint

Milder and sweeter than spearmint, Moroccan mint is the traditional base for Maghrebi mint tea. It has a slightly spicy, almost floral note and is particularly attractive to pollinators when it flowers. A good choice if you want a less assertive flavour in cooking.

Chocolate Mint

A novelty variety with a genuine cocoa-like scent when the leaves are crushed. The dark reddish stems make it ornamental as well as useful. Slower-growing than spearmint, so it suits a smaller pot.

Apple Mint (Mentha suaveolens)

Soft, downy grey-green leaves with a mild, fruity flavour. Apple mint makes an excellent mint sauce and is less overpowering for beginners who find standard spearmint too sharp. The woolly leaves are distinctive and attractive.

Pineapple Mint (Mentha suaveolens ‘Variegata’)

A variegated form of apple mint with cream-splashed leaves and a light pineapple fragrance. It holds the RHS Award of Garden Merit (AGM), which means it has been independently trialled by the RHS and confirmed to be reliably garden-worthy in UK conditions. It is more compact than many mints, making it excellent for window boxes and smaller pots.

One pot, one variety: Different mints cross-pollinate and can lose their distinctive flavour over time if grown together. Keep varieties in separate containers.

Containers, Pots and Compost

Mint is not fussy about pot material — terracotta, plastic, glazed ceramic and fabric pots all work. What matters is size and drainage.

Pot size

A minimum diameter of 30 cm (12 inches) gives the roots enough room to spread and reduces how often you need to water. Deeper is better: at least 25 cm depth prevents roots from circling at the base too quickly. Window boxes work well for multiple small plants, but keep spearmint or peppermint out — their vigour means they need a dedicated pot.

Drainage

Mint needs consistently moist soil, but sitting in waterlogged compost causes root rot. Every container must have drainage holes. If yours doesn’t, drill several before planting. Elevate pots slightly on pot feet or bricks to stop the drainage holes from blocking.

Compost

A peat-free multipurpose compost is ideal. Mix in around 20% horticultural grit or perlite to improve drainage and prevent compaction. Avoid using garden soil in pots — it compacts too densely in a container and often carries weeds or disease.

For more detail on getting your growing medium right, read our guide to the best compost for container gardening.

If you’re still deciding which pot to buy, our roundup of the best containers for beginners covers sizes, materials and where to buy in the UK.

How to Plant Mint in a Pot

The best time to plant mint outdoors is from late April through to September, once the risk of a hard frost has passed. You can plant earlier if you keep the pot in a frost-free greenhouse or on a sheltered windowsill indoors.

Starting from a garden centre plant

This is the quickest route to a productive harvest. Most UK garden centres stock pot-grown spearmint and peppermint from spring onwards, usually priced between £2 and £4.

1. Fill your container to within 5 cm of the rim with compost mix.
2. Water the compost and allow it to drain fully before planting.
3. Gently ease the mint from its original pot, tease out any tightly circling roots, and place it in the centre of the new container.
4. Backfill with compost, firming lightly. The base of the stem should sit at the same depth as it was in the original pot — do not bury the crown.
5. Water well and place in a bright, partially shaded position.

Starting from cuttings

Mint roots remarkably easily from stem cuttings. Take a cutting around 10–15 cm long, remove the lower leaves, and place it in a glass of water on a bright windowsill. Roots will appear within one to two weeks. Once roots are 3–5 cm long, pot up into compost as above.

Dividing an existing plant

If you already have a mint plant that has become congested, division is the most productive way to make new plants. In early spring or autumn, knock the root ball out of its pot and pull it apart into sections, each with several roots attached. Pot up each section individually.

Ongoing Care: Watering, Feeding and Pruning

Watering

Mint is a moisture-loving plant, and containers dry out faster than open ground. During the growing season (April to October), check the compost every one to two days in warm weather — push a finger 2–3 cm into the surface. If it feels dry, water thoroughly until water drains from the base of the pot.

In prolonged summer heat, you may need to water daily. Conversely, during cool, damp periods in spring and autumn, reduce watering to avoid waterlogging. Mint grown indoors on a windowsill dries out faster than outdoor pots in shadier positions — adjust accordingly.

Feeding

Mint in a container depletes compost nutrients faster than plants in the ground. From May to August, apply a balanced liquid fertiliser (such as a general-purpose liquid feed at half the recommended strength) once every two to three weeks. Avoid high-nitrogen feeds, which produce lush but flavourless growth.

Repot into fresh compost every one to two years, or when you see a dense mat of roots escaping from the drainage holes.

Pruning and pinching out

Regular harvesting is itself a form of pruning, but deliberate pruning helps maintain a bushy, productive plant. Pinch out the growing tips once plants reach around 20 cm tall — this encourages the plant to branch outward rather than growing tall and leggy.

When mint begins to flower (usually July to August), cut the flowering stems back hard to just above a pair of leaves. Flowering diverts energy from leaf production and can reduce flavour intensity. Left unchecked, a mint that has set seed often loses vigour the following year.

After the first hard frost, cut the plant back to around 5 cm above the compost surface. This removes tired and potentially diseased growth and prepares the plant for winter dormancy.

Harvesting Mint

You can begin harvesting as soon as the plant is established and growing strongly — typically four to six weeks after planting a young bought plant. The key rule is: never remove more than one-third of the plant at a time. Cropping too hard weakens the root system and slows regrowth.

How to harvest

Pinch or cut stems just above a leaf node (the point where a leaf joins the stem). The plant will send out two new shoots from below the cut, creating a progressively bushier and more productive plant with each harvest.

Harvest in the morning after any dew has dried, when the essential oil content — and therefore the flavour — is at its peak.

Storing your harvest

Fresh mint keeps for up to a week in a glass of water in the fridge, loosely covered with a plastic bag. For longer storage, leaves can be dried by hanging small bundles upside down in a warm, airy place for one to two weeks, then crumbling into an airtight jar. Alternatively, freeze whole leaves on a tray and then transfer to a freezer bag — they are perfect for use in cooking straight from frozen.

Common Problems and How to Fix Them

Mint rust

The most serious disease affecting UK-grown mint. Caused by the fungus Puccinia menthae, it appears as orange-brown powdery pustules on the undersides of leaves, with yellow spots on the upper surface. The RHS advises removing and binning (not composting) affected growth immediately. There is no approved fungicide for home use — the only organic control is to cut the plant back hard and allow clean regrowth. Improve air circulation around pots and avoid wetting foliage when watering.

Aphids

Clusters of greenfly or blackfly on new growth in spring and early summer. Remove them by squashing by hand, applying a strong jet of water, or using an organic insecticidal soap spray. Aphid infestations are usually minor and rarely kill an otherwise healthy mint plant.

Leggy, pale growth

A sign of insufficient light. Mint prefers partial shade but needs at least three to four hours of bright, indirect light daily. Move the pot to a brighter position. Leggy plants can be cut back hard and will regrow more compactly in better light.

Yellowing leaves

Can indicate overwatering (check drainage holes are clear), a nitrogen deficiency (start a fortnightly liquid feed), or simply natural leaf ageing at the base of the plant. If the whole plant yellows rapidly, check for root rot — roots should be pale and firm, not brown and mushy.

Wilting despite regular watering

If the compost feels moist but the plant still wilts, the roots may have become so congested that they can no longer take up water efficiently. Knock the plant out and check: if the root ball is a solid, tangled mass, divide the plant or repot into a larger container with fresh compost.

Overwintering Mint in Pots

Mint is a hardy perennial across most of the UK (RHS hardiness rating H6 — hardy in all of the UK, surviving to -20°C). It dies back to ground level in winter and regrows from the root system in spring.

Container-grown mint needs a little extra care in winter because pot-bound roots are more exposed to freezing temperatures than roots insulated by the ground.

Steps for overwintering success

1. After the first hard frost, cut top growth back to 5 cm above the compost.
2. Move pots to a sheltered spot: against a south-facing wall, inside an unheated greenhouse or cold frame, or into a garage or shed with some natural light.
3. Wrap terracotta pots in bubble wrap or hessian to prevent the compost from freezing solid and cracking the pot.
4. Water sparingly during winter — just enough to stop the compost from drying out completely. The plant is dormant and needs very little moisture.
5. Bring pots back out into the open once night temperatures stay reliably above -5°C, usually from March onwards in most parts of England and Wales (later in Scotland and Northern Ireland).

If you want year-round mint on a kitchen windowsill, bring one pot indoors in October before it dies back. In a warm, well-lit kitchen it will continue producing leaves through winter, though growth will be slower.

Frequently Asked Questions

Can I grow mint in a small pot or window box?

Yes, with caveats. A small pot (under 20 cm) will need watering daily in warm weather and will need dividing or repotting annually. Compact varieties like pineapple mint (‘Variegata’) or chocolate mint suit smaller containers better than vigorous spearmint or peppermint.

Does mint need full sun or shade?

Mint performs best in partial shade — around three to four hours of direct sun per day, with shade during the hottest part of the afternoon. Full sun causes the compost to dry out too quickly and can scorch the leaves. Deep shade produces leggy, flavourless growth. A north-facing wall in the south of England, or east-facing elsewhere, is often ideal.

How do I stop mint taking over even in a pot?

Check the pot every spring and cut away any stolons (horizontal runners) that have crept over the rim and into surrounding soil. Repot every one to two years, discarding the outermost, most congested roots. Keep pots on hard standing (paving or gravel) rather than directly on soil — stolons can work their way through drainage holes into the ground beneath.

My mint has flowered — is it ruined?

Not at all. Cut the flowering stems back to healthy leaf growth straight away. The plant will produce a flush of fresh, flavoursome leaves within two to three weeks. Allowing mint to flower and set seed does reduce leaf production and can cause some loss of variety character (especially in hybrid varieties), so regular deadheading pays off.

Can I grow mint from supermarket bunches?

Often, yes. Place the cut stems in a glass of water on a bright windowsill. Many supermarket mint bunches root within one to two weeks, after which you can pot them up into compost. Success rate varies — choose the freshest bunch you can find, and use stems that still have their growing tips intact.

What Next

Once you have mint established in a pot, the logical next step is building a productive container herb garden around it. Basil is another herb that does exceptionally well when given the right container conditions — read our complete guide on how to grow basil in a pot in the UK for step-by-step planting, care and harvesting advice.

If you’re thinking bigger than herbs alone, our plant care hub. For another container-friendly herb, see our guide to growing rosemary in pots covers care guides for a wide range of garden plants, from shrubs and perennials through to vegetables and fruit.

For a full overview of which herbs thrive alongside mint on a patio or balcony, don’t miss our guide to the best herbs to grow in containers — it covers varieties, pot sizes and positioning for a complete patio herb setup.

This guide follows RHS recommendations. For further reading, see the RHS advice pages on growing mint.