Beginner's Guide to Growing Food in Small Spaces

Start with the light you actually have

Before you buy a single pot, spend a day watching your growing space. Most fruiting crops — tomatoes, courgettes, peppers, runner beans — need at least six hours of direct sunshine in summer to earn their keep. Leafy crops are far more forgiving: salad leaves, chard, spinach, parsley and mint will manage on three or four hours, and simply grow a little more slowly in partial shade.

A north-facing balcony is not doomed, but it is best treated as a herb and leaf patch rather than a tomato farm. A sunny windowsill, by contrast, can be surprisingly productive. The trick in every case is to match the crop to the light, rather than fighting the space you have.

Windowsill herbs: the cheapest place to begin

Herbs give you the fastest return on the smallest investment, and they taste far better than the tired plastic packets on the supermarket shelf. A 15cm pot on a bright kitchen windowsill is enough for a single basil plant, provided you water it from the base and pinch out the flower buds as they appear — once basil flowers, the leaves turn bitter and the plant gives up.

A few rules that save a lot of disappointment:

• Mint must have its own pot. It spreads by underground runners and will smother anything sharing its compost.
• Rosemary and thyme prefer gritty, free-draining compost and far less water than basil. Treat them mean and they will reward you for years.
• Parsley germinates slowly, often taking three weeks. Soak the seed overnight and be patient rather than resowing.
• Chives are almost indestructible. Snip the leaves to about 2cm above the compost and they will regrow within a fortnight.

Turn pots a quarter-turn every few days so the plants grow straight rather than leaning towards the glass.

Balcony and patio pots that actually crop

Container growing succeeds or fails on pot size. As a rough guide, a tomato plant wants a pot of at least 10 litres, ideally 30cm across; a courgette wants 20 litres or more; salad leaves and radishes will manage happily in a 30cm-wide trough just 15cm deep. Small pots dry out fast and stunt plants, so it pays to buy fewer, bigger containers.

Use a peat-free multipurpose compost for salads and herbs, and mix in some soil-based compost for anything that will live in the pot all summer — it holds nutrients and moisture for longer. Check that every container has drainage holes, stand pots on saucers or feet, and raise them slightly off the ground so water can escape freely.

Wind is the hidden enemy on upper floors. Tie tall plants to a sturdy cane, choose compact or trailing varieties, and consider a low screen of netting or bamboo to break the worst of the gusts. If your balcony has a weight limit, remember that wet compost is heavy — a 10-litre pot can weigh upwards of 12kg once soaked.

Compact raised beds and growing upwards

A raised bed 20–30cm deep is plenty for salads, herbs, chard, beetroot and most dwarf varieties of carrot. Deeper beds of 40cm open up maincrop carrots, parsnips and climbing beans. Place the bed on slabs or a hard surface rather than soil, so you are not importing weeds, and leave a 60cm path around it for easy access and watering.

Where floor space is scarce, think vertically. Wall-mounted planters take salads and strawberries, a simple trellis supports peas and climbing beans, and a hanging basket planted with a tumbling tomato variety can crop well through late summer. Spacing matters more than quantity: overcrowded plants compete for light and water, and are far more prone to mildew and mould. Give each plant the room the seed packet suggests, even if the bed looks sparse at first.

Watering, feeding and the everyday routine

In high summer, containers may need watering twice a day — once in the morning and again in the early evening if the compost feels dry at fingertip depth. Water the compost, not the leaves, and water thoroughly until it runs out of the drainage holes. Self-watering containers or a simple drip line take the guesswork out of a busy week.

Feeding is straightforward. Salad leaves and herbs need very little. Once a tomato plant has set its first truss of flowers, switch to a high-potash liquid feed once a week. When it comes to pests, a nightly torchlit patrol for slugs and snails does more good than any gadget, and a fine net over brassicas stops cabbage white butterflies from laying eggs.

For a steady supply rather than a glut, sow salad seed in small batches every two or three weeks from March to August. Harden off anything raised indoors before planting out, and wait until the risk of frost has passed — mid-May in the south, and late May or early June further north.

Small harvests, repeated often

Pick little and often. Cut salad leaves about 3cm above the compost and they will regrow two or three times. Harvest courgettes while they are small and tender, and keep picking runner beans to encourage more flowers. A notebook, however scruffy, is worth more than any app: note what you sowed, when it cropped and what failed, and next year's plan writes itself.

Start with three pots and one herb trough. Get those right, and you will have learned everything needed to expand — into a second raised bed, a windowsill of winter salads, or a surprisingly generous harvest from a modest British garden.