Growing Lettuce in a pot
For balcony, patio or terrace — Lactuca sativa
lettuce grows well in a pot of at least Ø 20 cm (6 L capacity), in a position with full sun or partial shade. Watering: daily in heatwaves in summer, once a week in winter.

Which pot?
Ø 20 cm
~ 6 L potting soil
Give the plant room with a pot slightly wider than the current rootball, with matching depth.
Watering
daily in heatwaves
once a week
Always use a pot with drainage holes. Water dries out faster in pots — or the plant drowns. Check weekly with your finger: only water when the top 2 cm of soil is dry.
Pot care
Lettuce has high water needs and shallow roots, so consistent watering is the single most important maintenance task. In dry weather, water daily or every other day, aiming for the soil rather than the leaves to reduce disease risk. In spring and autumn, two to three times a week is usually sufficient. Mulching with a thin layer of compost or well-rotted manure helps retain moisture and keeps roots cool, which is especially valuable in summer. Feed lettuce lightly in April and May if your soil is not particularly rich. A balanced liquid fertiliser applied every two to three weeks, or a top-dressing of pelleted poultry manure, encourages steady leafy growth. Avoid high-nitrogen feeds late in the season, as they can promote soft, disease-prone growth. If you've prepared the soil well with compost, additional feeding is often unnecessary. Lettuce is hardy to zone 4a, so it tolerates light frosts, but growth slows significantly below 5°C. Protect early spring and late autumn crops with cloches, fleece, or a cold frame to extend the season. In winter, you can grow hardy varieties under cover for fresh leaves, though growth will be slow. Slugs and snails are the primary pests, especially on young plants. Check regularly in the evening and use barriers, traps, or organic pellets. Aphids occasionally cluster on the undersides of leaves; wash them off with water or tolerate low numbers, as they rarely cause serious harm. Downy mildew appears as yellow patches on leaves with grey mould beneath, particularly in cool, damp conditions—improve spacing and air flow, and avoid overhead watering. Lettuce root aphid can cause wilting; rotate crops and avoid replanting lettuce in the same spot year after year.
Pot-specific tip: add slow-release fertiliser pellets in March — potting soil exhausts much faster than open ground.