How to Grow Winter Salad Leaves in Containers

Quick facts

Best for	Balconies, patios, courtyards, porches and bright windowsills
Difficulty	Beginner-friendly, with some protection from the weather
Container depth	About 15cm minimum; a wide trough is ideal
Light	As much winter light as possible, in a sheltered spot
When to sow	Late summer to early autumn outdoors; into late autumn under cover
Best harvest	A few leaves per plant at a time, from autumn to spring

Why winter salads suit a tiny garden

Most container crops finish in autumn, which leaves pots and troughs sitting empty until spring. A few hardy salad leaves can fill that gap. They are small, cope with cold weather far better than lettuce bred for summer, and a single trough by the back door gives you something fresh to pick when the shops are full of imported bags.

They also make the most of a small space. Winter salads are low-growing and shallow-rooted, so they fit in window boxes and troughs, and they are easy to move closer to a wall or under cover when the weather turns.

The best salad leaves for winter containers

Choose leaves that are known to be hardy, and look for seed sold for autumn or winter sowing. Mixed winter salad packets usually contain several of these.

Leaf	What to expect
Lamb's lettuce (corn salad)	Small rosettes of soft, mild leaves. One of the hardiest salads and a reliable choice for winter pots.
Winter purslane (claytonia)	Fleshy, mild, round leaves. Very hardy and good for cut-and-come-again picking.
Land cress	A peppery leaf that tastes like watercress but grows in ordinary compost. Likes moisture and copes with some shade.
Rocket	Peppery leaves that grow well in cool weather. Salad rocket is quicker; wild rocket is slower and longer-lived.
Mizuna	Frilly, mild leaves with a slight mustard flavour. Quick to establish from late-summer sowings.
Mustard leaves	Spicy green or red leaves that add colour and heat. Pick them young, as larger leaves are very hot.
Winter lettuce	Some lettuce varieties are bred for autumn sowing and overwintering. Check the packet, as most lettuce is not hardy enough for a winter outdoors.

When to sow winter salads

Timing is the key to winter salads. Plants need to be well established before the short, cold days of late autumn, because very little grows between late November and late January.

• Late summer to early autumn is the main sowing time for leaves to pick through autumn and winter outdoors. Check each packet, as the latest sowing date varies between crops.
• October and November sowings will grow very slowly outdoors. Sow them under cover instead, in a cold frame, mini greenhouse, unheated porch or on a bright windowsill, and expect most of the picking in late winter and early spring.
• Young plants of winter salads are sometimes sold in autumn. Planting these into a trough is a quick way to catch up if you missed the main sowing window.

Choosing a container

Use a trough, window box or wide pot at least 15cm deep, with drainage holes. A wider container holds more plants and stays evenly moist for longer, while drainage matters more in winter than at any other time of year. Salad leaves sitting in cold, wet compost are much more likely to rot than to die of cold.

Use fresh peat-free multi-purpose compost. If you are reusing a pot from a summer crop, remove some of the old compost and mix in fresh before sowing.

How to sow winter salad leaves

1. Fill the container with compost to just below the rim and water it so it is evenly moist.
2. Sow thinly in short rows or scatter the seed across the surface, following the depth on the packet. Most salad seed needs only a light covering of compost.
3. Label each row, especially if you are sowing several different leaves.
4. Keep the compost moist, but not wet, until the seedlings appear.
5. Thin seedlings that come up crowded so that each plant has room to grow. The thinnings can be eaten.
6. If you are sowing different crops, sow a short row of each rather than a whole trough of one, so a single failure does not leave you with nothing.

Where to put the container

In winter, light matters more than anything else. Put the trough in the brightest spot you have, ideally where it gets whatever low sun there is. A position close to a wall is a good choice, because the wall gives shelter from wind and a little extra warmth.

• Raise the container on pot feet or bricks so it drains freely.
• Keep it out of the path of cold, drying winds where you can.
• A covered balcony or porch keeps off heavy rain, but check that the plants still get enough light.
• On a windowsill, use your brightest window and keep leaves away from very cold glass on frosty nights.

Protecting winter salads from cold and wet

Hardy salad leaves survive frost, but the leaves are better quality with some protection. A cover keeps off the worst of the rain and wind and keeps the plants growing a little longer into the season.

• Horticultural fleece can be laid over the trough on cold nights. Secure the edges so it does not blow away.
• A cloche or mini greenhouse gives longer-lasting cover for a trough or a group of pots.
• Ventilate on mild days. Closed covers trap damp air, which encourages mould on the leaves.
• Do not pick frozen leaves. Wait until they have thawed, as frozen leaves bruise and spoil easily.

Watering

Winter salads need much less water than summer crops, and overwatering is a more common problem than drought. Check the compost with your finger and water only when the top feels dry. Containers under cover, on covered balconies or against a sheltered wall can still dry out, so do not stop checking altogether.

Water in the morning, at the base of the plants, so the leaves and compost surface are not wet going into a cold night. Empty any saucers so the container never stands in water.

Fresh compost provides enough food for winter salads. Feeding is not usually needed until growth picks up again in spring.

Harvesting through winter

Pick a few outer leaves from each plant rather than cutting the whole trough at once. Leave the centre of each plant to keep growing. In midwinter growth is very slow, so take a little from several plants and give each one time to recover.

Lamb's lettuce can also be harvested by cutting whole rosettes, which is useful if you have sown it thickly. Winter purslane, land cress, mizuna and mustard leaves can be picked leaf by leaf or cut a little above the base and left to regrow.

As the days lengthen in late winter and early spring, growth speeds up and picking becomes much more generous. Many winter salads then start to flower. Once a plant is running to flower, the leaves become tougher or stronger in flavour, so clear the trough and resow for spring.

Common problems

Slugs and snails

Slugs keep feeding in mild, wet winter weather. Raise the container off the ground, check under rims and pot feet, and look over the plants on damp evenings.

Mouldy or rotting leaves

Damp, still air and wet compost are the usual causes. Remove affected leaves, water less, and open covers on mild days to let air move around the plants.

Birds pecking the leaves

Pigeons and other birds sometimes strip leafy crops in winter, especially mizuna and mustards. Netting or fleece over the trough solves this.

Plants not growing

Very slow growth in December and January is normal. If plants are small and pale even in autumn or spring, move the container to a brighter spot and check that it drains well.

A simple winter salad plan

Fill one wide trough with fresh compost and sow short rows of lamb's lettuce, winter purslane and rocket. Stand it against your sunniest sheltered wall, keep a sheet of fleece handy for hard frosts and pick a few leaves at a time. For quicker results through the darkest weeks, add a tray of pea shoots or microgreens on the windowsill.

For more leafy crops, see how to grow lettuce in pots, spinach in pots and pak choi in containers. For the rest of this season's planting, see what to sow in October and what to sow in November.

FAQs

Which salad leaves are the hardiest?

Lamb's lettuce and winter purslane are two of the hardiest salad leaves. Land cress, rocket, mizuna and mustard leaves also cope well with cold weather, especially with a little protection.

Is it too late to sow winter salads in October?

Not if you can sow under cover, in a cold frame, mini greenhouse, porch or on a bright windowsill. Outdoor sowings made this late grow very slowly and usually crop in late winter and spring.

Can I grow winter salad leaves on a windowsill?

Yes, on a bright windowsill. Growth will be slower than in spring and summer, so sow small batches and pick a few leaves at a time.

Do winter salads need protecting from frost?

Hardy salads usually survive frost, but a cover of fleece or a cloche during cold spells keeps the leaves in better condition and keeps off heavy rain.

Can I grow ordinary lettuce in winter?

Most lettuce is not hardy enough to grow outdoors through winter. Choose a variety sold for autumn sowing, or grow hardier leaves such as lamb's lettuce and winter purslane instead.