Growing Your Own Vegetables in Small Spaces

Small Space, Real Harvests

A sunny doorstep, a balcony railing, a few pots against a south-facing wall — that is genuinely enough to keep a household in salad from May to October. The trick is not squeezing in as much as possible, but choosing crops that give a generous return for the space they occupy. Salad leaves, herbs, tomatoes, chillies and radishes all crop well in containers, often within weeks rather than months.

Aim for the sunniest spot you have. Most of these crops want six hours of direct light a day. Salad leaves, chives, mint and parsley will manage with four, so save the shadiest corner for them and give the tomatoes the best seat in the house.

Choose Your Containers Carefully

Size matters far more than appearance. A tomato in a 20cm pot will sulk and crop poorly; the same plant in 25–40 litres of compost will fruit for months. As a rough guide:

• Herbs: individual 15–20cm pots for basil, parsley, chives and thyme. Mint needs a pot entirely to itself or it will shoulder everything else aside.
• Salad leaves and radishes: shallow troughs or 30cm-wide pots, at least 15cm deep.
• Tomatoes, chillies and aubergines: 25–40 litres each, one plant per pot.
• Dwarf French beans and peas: a 40cm pot with a few short canes or a small wigwam for support.
• Strawberries: three or four plants in a 35cm pot, or a purpose-made tiered planter.

Whatever you use, drainage is non-negotiable. Check for holes, add a 2cm layer of gravel or broken crocks in the base, and raise pots on feet or bricks so surplus water can escape. Terracotta looks lovely but dries out fast; plastic is less charming and considerably more forgiving on a hot afternoon.

Compost Is Not Soil

Fill your containers with a good peat-free multipurpose compost, mixed with a handful of grit or perlite per pot to keep it open and free-draining. Never use garden soil — it compacts in a container, drains badly and smuggles in weed seeds.

Fresh compost carries enough nutrients for roughly six weeks. After that, you take over. Begin feeding tomatoes and chillies when the first flowers set, using a high-potash tomato feed once a week and following the dilution on the bottle. Leafy crops such as chard and spinach prefer a general-purpose feed, but at half strength. Herbs are the exception: rosemary, thyme and oregano do best on poor rations, as rich compost dilutes their flavour.

Sowing for a Steady Supply

The most common mistake is sowing an entire packet of salad at once and facing a glut followed by a famine. Instead, sow a small pinch every two to three weeks from March through to September. This succession habit keeps a constant supply of young leaves on the go.

• Cut-and-come-again leaves — rocket, mizuna, chard, spinach and loose-leaf lettuces — can be snipped with scissors at 5–8cm and will regrow two or three times.
• Radishes are ready in three to four weeks and thrive in a shallow trough between slower crops.
• Spring onions can be sown thickly and pulled young as needed.
• Tomatoes and chillies are easiest bought as plug plants if windowsill space is tight; harden them off over a week before planting out after the last frost.

Watering, Weather and Pests

Containers dry out quickly, and a tomato in a 30cm pot may need watering twice a day in July. Water in the morning, then check again in early evening — if the compost is dry a couple of centimetres below the surface, water again. A saucer helps, but empty it if it stays full, as soggy roots rot.

Wind is the balcony grower's quiet enemy. It topples pots and shreds leaves. Group containers together for mutual shelter, weight the bases, and fix a simple windbreak of netting if you are exposed. Slugs and snails adore a damp pot even more than open ground, so check beneath the rims at dusk, run copper tape around the base, or set a gritty barrier. Greenfly can usually be blasted off with a strong jet of water.

Blight is the real risk for outdoor tomatoes in a wet British summer. Growing a blight-resistant variety, or sheltering plants under a small clear plastic cover, makes a genuine difference. Water the compost, not the leaves, to keep foliage dry.

Keeping It Going Through Winter

Small spaces need not go quiet in November. Winter salads such as landcress, winter purslane and lamb's lettuce will crop in a sheltered spot or under a cloche, and hardy herbs like thyme, rosemary and winter savoury carry on regardless. Sow a final round of cut-and-come-again leaves in late August for picking into autumn, and leave a few pots empty over winter so you can refresh the compost in spring.

Start small, learn what your particular patch of sun and wind will tolerate, and add a pot or two each year. A single tomato plant that fruits on a doorstep gives more pleasure than half a row of something that never quite ripens.