Growing Mint in Pots (and Containing It)

The short answer to the great mint problem is simple: grow it in a pot. Mint is one of the easiest, most rewarding herbs you can grow in a UK garden, but planted loose in a border it will romp away and swamp everything around it within a season or two. Keep it in a container and you get all the fresh leaves you want, on tap, with none of the takeover.

This guide covers the best way to pot mint up, how big a pot to use, the clever sunken-container trick for borders, and how to keep a potted plant happy year after year. For the full picture on choosing varieties, harvesting and using your mint, see the main guide to growing mint.

Why pots are the best way to grow mint

Mint spreads by runners — fast, horizontal underground stems that creep outwards, root as they go, and send up new shoots wherever they touch soil. It is brilliantly efficient and exactly why a single plant can colonise a whole bed. Once those runners are loose in open ground they are genuinely hard to dig out, because even a small fragment left behind will regrow.

A pot solves this neatly. The walls of the container physically stop the runners escaping, so the plant stays exactly where you put it. You get the vigour of mint working for you — a generous, productive plant — without it bullying your other herbs.

There are other reasons a pot suits mint well. You can stand it right by the back door so leaves are an arm's reach from the kitchen. You can move it into a bit more sun or shade as needed. And if you grow more than one type — spearmint, peppermint, a chocolate or apple mint — separate pots stop them tangling into one another underground. This contained, low-fuss approach is why mint earns its place among the easiest crops for beginners, and why it sits so comfortably alongside other herbs and veg grown in containers.

Choosing and filling a pot

Mint is not fussy about its container, but a few choices make life easier.

Size. A 20–30cm diameter pot (roughly 5–10 litres) is ideal for a single plant. That gives the roots room to bulk up into a full, leafy clump without the pot being so large it dries out unevenly. Mint will fill a pot of this size within a season — that is normal, and the cue to divide it the following spring.

Material. Plastic, glazed ceramic and metal all work and hold moisture well, which matters because mint hates drying out. Terracotta is fine and looks lovely, but unglazed clay wicks water away through its sides, so a terracotta pot will need watering more often. Whatever you choose, it must have drainage holes in the base.

Compost. Fill with a good peat-free multipurpose compost. Peat-free is the standard, environmentally sensible choice in the UK now and suits mint perfectly. If you have it, mixing in a couple of handfuls of home-made compost or some garden soil adds body and helps the pot hold moisture between waterings.

Drainage. You don't need a deep layer of crocks. Just make sure the holes are clear, sit the pot on feet or a couple of stones so water drains freely, and you're set. Mint likes moisture but not waterlogged, stagnant roots.

To plant, part-fill the pot, set the mint so its rootball sits about 2cm below the rim, backfill around it, firm gently and water in well.

The sunken-container trick for borders

What if you genuinely want mint in a border — spilling along a path edge or filling a gap — without the spread? The classic gardener's solution is to plant it in a pot, but bury the pot.

Here's how:

1. Take a large container — a 30cm+ plastic pot, an old bucket or a sturdy tub — and cut or knock the bottom out of it so it becomes a bottomless sleeve. (Leaving a base in works too, but a bottomless one drains better.)
2. Dig a hole in the border and sink the container into it, leaving the rim standing a few centimetres proud of the soil surface. That lip is the important bit — runners will try to escape over the top, and a raised rim stops them sneaking out at ground level.
3. Fill the buried container with compost and plant your mint inside it, just as you would in any pot.

The walls of the sunken sleeve block the runners underground, while the proud rim catches any that try to creep over. Once or twice a season, snip off any stray shoots that have arched over the edge. It's a brilliantly simple bit of containment that lets you enjoy mint in the ground without losing the rest of the bed to it.

Care in a pot

Once it's planted, mint asks very little — but the one job you can't skip is watering.

Water often. Pots dry out far faster than open ground, especially in a sunny spot or a hot UK summer, and mint wilts dramatically the moment it goes short. Check it daily in warm weather and water whenever the top of the compost feels dry. A wilted mint plant usually perks back up after a good drink, but repeated drought stress weakens it and scorches the leaves. Mint is happy in full sun or part shade; a little afternoon shade actually helps the compost stay moist.

Feed lightly. Mint in fresh compost won't need feeding for the first couple of months. After that, a fortnightly liquid feed (a balanced or general-purpose feed) through the growing season keeps the leaves lush and green, since the goodness in a pot gets used up or washed out faster than in the ground.

Cut back for fresh growth. Harvest regularly by pinching out the soft top growth — this keeps the plant bushy and stops it flowering. If it does flower or get straggly by midsummer, cut the whole plant back hard, to about 5cm. It looks brutal, but mint bounces back within a couple of weeks with a flush of tender new leaves, which are the best ones for cooking.

Dividing and refreshing each spring

This is the secret to mint that stays good for years rather than fizzling out. A potted mint quickly becomes pot-bound — the roots fill every bit of space, exhaust the compost, and the plant starts to sulk: smaller leaves, weaker growth, faster wilting.

The fix is to divide and refresh it every spring, just as the new shoots appear (usually March or April). Tip the plant out of its pot, and you'll see a dense mat of roots and runners. Either pull or cut the clump into two or three pieces — each with some roots and a few shoots — and replant one piece into the same pot with fresh peat-free compost. The spare pieces can go into new pots, be passed on to friends, or be composted.

Dividing keeps every plant young, vigorous and productive, and it's the natural moment to top up the compost that mint has used. One plant easily becomes a row of pots this way, at no cost. If you've never split a plant before, the same straightforward technique applies to several herbs — there's more in the guide on growing mint.

Indoor and windowsill pots

Mint also grows happily indoors, which is handy over winter or if you have no outdoor space at all. A small pot on a bright kitchen windowsill gives you fresh leaves within reach of the chopping board.

Indoors, give it the brightest spot you have — an east- or west-facing sill is ideal, as full midday sun through glass can scorch the leaves. Water whenever the surface feels dry; centrally heated rooms dry pots out quickly. Turn the pot every few days so it grows evenly towards the light rather than leaning, and harvest regularly to keep it compact.

Indoor mint won't be quite as vigorous as a plant outside in summer, and it appreciates a spell outdoors in the warmer months to build itself back up. Treat it as a top-up supply rather than your whole crop, and it'll serve you well through the colder half of the year.

Get the pot, the watering routine and the spring divide right, and mint is about as close to foolproof as growing gets — generous, fragrant and entirely under control. For everything else, from the best varieties to harvesting and using your leaves, head back to the main guide to growing mint.