Why a Raised Bed Works in a Small Space

If your garden is little more than a courtyard, a balcony or a narrow strip of lawn, a raised bed is the simplest way to grow something genuinely useful. Salad leaves are the ideal crop for it: they are quick, they take up very little root room, and they are expensive to buy but cheap to grow. A bed measuring roughly 1 metre by 1.2 metres will give you bowlfuls of leaves from spring right through to autumn, with a bit of planning.

Raised beds also solve several problems at once. The soil warms faster in spring, so you can sow earlier than in open ground. Drainage is better, which suits salad crops that sulk in waterlogged soil. And because you fill the bed yourself, you are not fighting whatever rubbish soil you inherited. Best of all, you can build it on paving, gravel or concrete, so a patio becomes productive ground.

Choosing a Spot and Building the Frame

Salad leaves want light, but they do not want to bake. Aim for somewhere that gets four to six hours of sun a day, with a little shade during the hottest part of the afternoon. That dappled midday relief slows down bolting, which is the main reason summer sowings turn bitter and run to seed.

Keep the width manageable. A bed no wider than 1.2 metres lets you reach the middle from both sides; if it sits against a wall or fence, keep it to 60–75 centimetres. Depth matters less than you might think — 20–25 centimetres is plenty for salad, and even 15 centimetres will do if the bed sits directly on soil.

• Use untreated timber, scaffold boards or gravel boards. Avoid anything that has held creosote or old paint.
• Level the ground first, then lay down a sheet of cardboard to smother weeds underneath.
• Line the base with a layer of broken pots or coarse gravel if drainage is poor.
• Leave a gap of at least 30 centimetres between beds so you can kneel and work comfortably.

Filling with Sieved Topsoil and Compost

This is the step most people rush, and it is the one that decides how well your leaves grow. The aim is a fine, crumbly tilth — the kind of texture that lets a tiny lettuce seed push through without a struggle. Sieving is worth the effort.

Mix roughly 60 per cent sieved topsoil with 40 per cent well-rotted compost or peat-free multipurpose compost. Push the topsoil through a 10-millimetre sieve to remove stones, lumps, roots and any bits of rubble. If you are filling from bags, buy a decent loam-based compost rather than cheap stuff that dries out to dust.

Stir in a couple of handfuls of blood, fish and bone per square metre. Salad is a leafy crop and appreciates nitrogen, but too much gives soft, sappy growth that slugs adore, so go steady. Firm the mix gently with your hands, water it well, and let it settle for a few days before sowing. Top up any dips once it has slumped.

Sowing Cut-and-Come-Again Varieties

Cut-and-come-again is exactly what it sounds like. Instead of pulling whole plants, you snip the leaves a couple of centimetres above the crown and the plant regrows. Most varieties will give you three or four good cuts before they tire.

Good choices include loose-leaf lettuces such as ‘Salad Bowl’ and ‘Oak Leaf’, rocket, mizuna, mustard ‘Red Giant’, pak choi, perpetual spinach and leaf chard. Mixing several together gives you bags of flavour and a bit of insurance if one variety sulks.

Sow into shallow drills about 1 centimetre deep and 10–15 centimetres apart, or simply scatter thinly across the surface and cover with a fine dusting of compost. Aim for seeds roughly 2–3 centimetres apart. In a 1.2-metre bed you can fit four or five short rows, which is more than enough for one household.

• March to April: sow under fleece or in a cold frame for the earliest leaves.
• April to August: sow direct outdoors, a short row every two to three weeks.
• Late August to September: sow winter-hardy types such as ‘Winter Density’ or land cress for autumn and spring picking.

Watering, Shading and Everyday Care

Regular water is what keeps leaves tender and stops the plants bolting. Little and often beats the occasional flood. In dry weather, aim for two to three litres per square metre every couple of days, and more during a heatwave. Water in the morning, directly at the base, and spread a thin mulch of compost between rows to hold moisture in.

If the bed faces full sun, rig up a bit of shade netting or an old sheet on hot afternoons in July and August. You can also let neighbouring taller crops cast a little shade over one end.

Watch out for slugs, which will find young seedlings overnight, and pigeons, which will strip a row in an afternoon. Fine mesh netting over a simple frame deals with both, and keeps flea beetle off your rocket. A evening patrol with a torch is remarkably effective.

Harvesting and Keeping the Supply Going

Cut with sharp scissors or a small knife, taking the outer leaves first or shearing the whole row about 3 centimetres above the base. Harvest in the early morning when leaves are crisp, and never take more than a third of the plant at once. Wash and use the same day for the best flavour.

After three or four cuts, growth slows and leaves turn bitter. Pull the tired plants, fork over the patch, add a handful of compost and resow. That simple cycle, repeated through the season, is what keeps a small raised bed producing salad from March until the first hard frosts.