A balcony of just a few square metres can produce a surprising amount of food. Herbs, salad leaves, tomatoes and peppers all grow well in containers, and tending them takes only a few minutes a day. Here is how to set up a small balcony garden that actually works.
1. Check your light
Sunlight decides what you can grow. Watch your balcony for a day and note how many hours of direct sun it gets.
- 6 or more hours: tomatoes, peppers, chillies, courgettes, beans and most herbs.
- 3 to 6 hours: lettuce, spinach, chard, rocket, radishes, peas, parsley and mint.
- Less than 3 hours: stick to leafy greens and shade-tolerant herbs, and expect slower growth.
2. Check weight and safety
Wet soil is heavy. Large containers can weigh 30 to 50 kilograms after watering. Place the heaviest pots near walls and supports rather than in the middle of the balcony, and check any building rules about weight, railings and dripping water onto neighbours below. Secure tall plants and pots against wind.
3. Choose the right containers
Bigger is better for most vegetables, because larger pots hold more moisture and nutrients. As a rough guide:
- Herbs and lettuce: 15 to 20 cm deep
- Peppers and dwarf tomatoes: at least 20 litres
- Full-size tomatoes and courgettes: 30 to 40 litres
Every container must have drainage holes. Fabric grow bags are light, inexpensive and allow roots to breathe. Self-watering pots with a reservoir are very helpful on hot, windy balconies.
4. Use potting mix, not garden soil
Garden soil compacts in containers and drains poorly. Use a good-quality peat-free potting mix designed for containers, and mix in some compost for extra nutrients.
5. Pick easy crops to start
For a first season, choose plants that are forgiving and productive:
- Salad leaves: cut-and-come-again lettuce and rocket can be harvested for weeks.
- Cherry tomatoes: compact or bush varieties suit pots well.
- Herbs: basil, parsley, chives, thyme and mint. Grow mint in its own pot, as it spreads aggressively.
- Radishes: ready to harvest in about four weeks.
- Chillies and peppers: attractive and productive in a sunny spot.
6. Water consistently
Containers dry out much faster than garden beds, especially in wind and summer heat. In hot weather you may need to water every day. Check the soil with your finger and water thoroughly when the top few centimetres feel dry. Watering in the morning reduces evaporation and leaf disease.
7. Feed regularly
Nutrients wash out of containers with every watering. Once plants are established, feed fruiting crops such as tomatoes and peppers every one to two weeks with a liquid fertiliser. Leafy greens need less feeding.
8. Make the most of vertical space
Railing planters, wall pockets and trellises let you grow upwards. Climbing beans, peas and cucumbers can be trained up a trellis, freeing floor space for pots.
Common beginner mistakes
- Pots that are too small, leading to constant wilting
- Planting too much at once and running out of space
- Forgetting to water on hot, windy days
- Choosing crops that need more sun than the balcony gets
Start with five or six containers, learn how your balcony behaves through one season, and expand from there.
Quick answers
How much sun does a balcony vegetable garden need? Most fruiting crops such as tomatoes, peppers and beans need at least six hours of direct sun a day. Leafy greens, herbs like parsley and mint, and radishes cope better with partial shade.
What size containers should I use? Bigger is usually better because large pots dry out more slowly. Tomatoes and courgettes do best in pots of 20 litres or more, while lettuce and herbs grow well in shallower troughs.
How often should I water? Containers can dry out quickly in summer, sometimes needing water daily. Water when the top few centimetres of compost feel dry, and water deeply until it drains from the bottom.
Do I need to fertilise? Yes. Potting compost runs out of nutrients after a few weeks. A balanced liquid feed every one to two weeks during the growing season, or a tomato feed for fruiting crops, keeps plants productive.
Is weight a problem on a balcony? Wet compost is heavy. Check any weight limits for your building, spread pots out and consider lightweight containers.
