How to Grow Vegetables in Pots and Containers

The one rule that matters more than any other: go bigger than you think

Almost every container-growing disappointment traces back to one thing: a pot that was too small. Small containers dry out fast, run low on nutrients fast, and restrict root growth, all of which show up as stunted plants and a disappointing harvest, even when everything else was done right.

If you're choosing between two pot sizes, take the bigger one. The extra compost costs very little next to the difference it makes to what you actually harvest.

What size pot for what crop

The minimum RHS gives on each crop's own page. RHS's general advice is to aim for at least 45cm deep and wide where you can, because smaller containers run short of water and nutrients.

Crop	Minimum container (RHS)	Notes
Basil, chives	20cm wide and deep	Parsley 25cm; rosemary 30cm, with plenty of drainage holes.
Thyme	15cm wide, 10cm deep per plant	Plenty of drainage holes.
Lettuce, salad leaves, radish, spinach	30cm wide and deep	Salad onions: a pot at least 30cm wide.
Carrots	Deep containers for long roots	Small, round varieties suit most pots; over 20cm deep for baby roots.
Garlic	25cm deep	Plant cloves 15cm apart, as in the ground.
Beetroot, chard	40cm wide and deep
Bulb onions	45cm wide and deep
Potatoes	30cm wide and deep	One seed potato per 30cm of width; earlies suit pots best.
Tomatoes	30 to 45cm pot per plant	Or two plants to a standard growing bag.
Chillies; sweet peppers	Chillies 22cm; peppers 30cm wide
Kale	30cm wide and deep	One mature plant.
Peas	45cm wide	Dwarf and mangetout types; RHS says peas grow best in the ground.
Courgettes	45cm wide	Compact or bush varieties only.
Dwarf French or runner beans	30 to 45cm wide
Climbing beans	75cm wide, 45cm deep	Heavy enough not to topple.

From each crop's RHS grow-your-own page and RHS's vegetables in containers guide, read 19 September 2026. Guides for the main pot crops: tomatoes, potatoes, carrots, courgettes and runner beans. Building a raised bed instead: how deep it should be and what to grow in it.

What grows easiest in containers

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Tomatoes

One of the best container crops there is, dwarf and bush varieties especially. Needs a sunny, sheltered spot and consistent watering.

🌶️

Peppers and chillies

Genuinely thrive in pots, partly because the warmth a container holds suits them. A sunny patio or balcony is often better than open ground for these.

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Salad leaves and herbs

The easiest possible starting point. Fast-growing, shallow-rooted, forgiving of imperfect conditions. A single trough can keep you in salad all summer.

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Dwarf beans

Look for varieties specifically described as 'dwarf' or 'patio': these stay compact and don't need the tall supports climbing varieties do.

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Potatoes

A genuinely rewarding container crop. Grow bags or large bins both work: start with a shallow layer of compost and keep 'earthing up' as the plant grows.

Three things container growing changes

Watering: more often than you'd expect

Containers dry out much faster than open ground, especially in summer. Daily watering is normal for many pots, and small containers in full sun may need it twice a day. Check by pushing a finger an inch into the compost, and if it's dry, water.

Feeding: compost runs out of nutrients fast

Compost in a pot has a finite supply of nutrients, and watering washes them through quickly. Start feeding 4–6 weeks after planting, roughly weekly for hungry crops like tomatoes and peppers.

Winter protection: roots are more exposed

Plant roots in a container are far more exposed to cold than roots in the ground, which is naturally insulated. Move pots against a sheltered wall, or wrap them, if you're overwintering anything.

Frequently asked questions

Can vegetables grow in pots?

Yes, most vegetables grow well in containers as long as the pot is large enough and gets enough sun. Tomatoes, peppers, salad leaves, herbs, dwarf beans, and even potatoes all do well in pots. Larger or deep-rooted crops like sweetcorn or main crop potatoes are harder to manage in containers.

What size pot do I need to grow vegetables?

It depends on the crop. RHS gives at least 20cm for basil and chives, 30cm wide and deep for lettuce, radish and potatoes, 30 to 45cm for a tomato, 45cm wide for courgettes and peas, and 75cm wide for climbing beans. Bigger is almost always better.

Do container vegetables need more watering than ones in the ground?

Yes, significantly more. Containers dry out much faster than open ground, especially in summer; daily watering is normal for many container crops, sometimes twice a day in hot weather for smaller pots.

A daily plan for your pots and containers too

Vercro keeps every crop you add, pots and containers included, and each morning Today shows what needs doing, wherever it's growing.

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