Growing salad leaves in pots on a sunny patio

There is something quietly satisfying about stepping onto the patio with a pair of scissors and a colander, and coming back with a handful of leaves that were growing ten seconds earlier. Salad leaves are perfect container crops: they are quick, they are forgiving, they do not need deep soil, and they will happily crop from a pot that would be far too small for a tomato. Even a modest sunny patio can keep a household in cut-and-come-again leaves from spring right through to the first hard frosts, provided you get a few simple habits right.

Why salad leaves suit pots so well

Most salad crops are shallow-rooted and fast-growing. They are harvested young, so they never need the root run of a courgette or the feeding regime of a chilli. A pot just 15–20cm deep is enough for lettuce, rocket, mizuna and most mustard greens. That means you can grow them on a windowsill, a doorstep, a balcony or a row of pots along a south-facing wall.

Pots also give you control. You can move them into shade when a July heatwave threatens to make everything bolt, lift them out of reach of slugs, and rotate them so nothing sits in the same tired compost for two seasons. Best of all, you can sow a small pot every fortnight and never face a glut or a gap.

What to sow

Forget the big hearting lettuces you see in supermarkets; they take up space and are slow to mature. Look instead for loose-leaf and cut-and-come-again types, which are the mainstay of a potted salad garden.

• Lettuce: 'Salad Bowl', 'Lollo Rossa', 'Red Salad Bowl' and 'Little Gem' all crop well in containers and give you a mix of colour and texture.
• Rocket: fast, punchy and ready in about three weeks. Sow it in its own pot, because it bolts quickly and you will want to resow often.
• Mizuna and mustard greens: peppery, hardy and reliably productive. Red mustard adds a lovely bronze tint to a bowl.
• Spinach 'Perpetual' and leaf beet: good for a steady supply of larger leaves, though they need a slightly deeper pot.
• Corn salad and winter purslane: sow these in late summer for picking through the colder months.

A seed packet of mixed salad leaves is a fine place to start, but separate pots give you far more control over what you pick and when.

Compost, pots and drainage

Use a peat-free multipurpose compost and mix in a couple of handfuls of garden compost or well-rotted leafmould per pot to help it hold moisture. Salad leaves are not greedy, so there is no need for rich feeding, but they do resent drying out.

Choose pots with plenty of drainage holes and stand them on pot feet or broken tiles so water can escape freely. A 30cm pot will take three or four lettuces, or a generous scattering of rocket. A shallow seed tray works beautifully for a dense crop of cut-and-come-again leaves, and is easy to move around. Fill pots to about 2cm below the rim so there is room to water without washing the compost over the edge.

Sow little and often

This is the single most useful piece of advice for anyone growing salad in containers. Do not sow a whole packet at once. Sow a small pinch every two to three weeks from early March until early September, and you will have a continuous supply rather than a fortnight of overwhelm followed by bare compost.

Sow thinly on the surface, cover with about 5mm of compost, and water gently with a fine rose or a mister. Germination usually takes seven to fourteen days. Once the seedlings are up, thin them to roughly 5cm apart for cut-and-come-again cropping, or 15–20cm for plants you want to grow into individual heads. The thinnings are delicious, so rinse them and add them to the bowl.

Watering and everyday care

Pots dry out far faster than open ground, so check them daily in warm weather, ideally in the morning. Keep the compost consistently moist but never waterlogged, and avoid splashing the leaves in the evening, which invites mildew. Grouping pots together creates a slightly damper microclimate and reduces the need to water so often.

Once you start harvesting, give the plants a weak liquid feed every fortnight. Salad leaves grown in fresh compost rarely need anything more. Watch for slugs and snails after rain, and cover young sowings with fleece if pigeons start pecking at the leaves. In high summer, move pots into light shade during the middle of the day; heat and drought are what make lettuce and rocket run to seed. Keep picking, too, because regular harvesting delays bolting.

Harvesting and keeping the crop going

With cut-and-come-again crops, either snip the outer leaves individually or take the whole plant down to about 3cm above the compost. Rocket, mizuna and mustard will regrow two or three times; loose-leaf lettuce usually gives you one or two extra cuttings before it tires.

Always pick in the cool of the morning, when leaves are crisp and full of water, and use them the same day if you can. Never strip the growing point in the centre of a lettuce, or the plant will stop producing. When a pot finally gives up, tip the spent compost onto the border or into the bin, refill with fresh compost, and sow again. Sow corn salad and winter purslane in August for picking from October onwards, and a pot of winter lettuce under a cloche or in a cold porch will keep you in leaves long after the last tomato has gone.