Vertical Growing Ideas for Balcony Vegetable Gardens

Read Your Balcony Before You Plant a Thing

Before you spend a penny on pots, spend ten minutes working out what your balcony actually offers. Which way does it face? A south-facing balcony can give six or more hours of summer sun, which is enough for climbing beans, tomatoes and peppers. East-facing gets good morning light before the heat builds — ideal for salad leaves and herbs that bolt in a blaze. West-facing is warm but late, so choose quick-maturing crops. North-facing balconies are the tricky ones: keep to mint, parsley, rocket and chard, and accept that fruiting crops will sulk.

Wind matters just as much. Upper-floor balconies can be ferocious, and wind dries compost faster than sunshine does. A bit of mesh netting tied to the railing will slow it down without creating a solid sail. Above all, protect your floor space. You still need to walk out there with a watering can, so the aim is to move as much growing as possible onto walls, railings and vertical frames, leaving a clear path down the middle.

Train Climbing Beans Up an Obelisk

Climbing beans are the single best value crop for a small balcony. They crop for weeks, look handsome, and grow upwards rather than outwards. Use a 1.5m obelisk or a simple wigwam of canes, and give it a pot at least 35cm across and 40cm deep — around 30 litres of compost — to support five or six plants.

• French climbing beans: 'Cobra' is reliable and heavy-cropping; 'Blauhilde' brings purple pods that turn green when cooked.
• Runner beans: 'White Lady' is self-fertile and sets well in still air; 'Scarlet Emperor' earns its place for the flowers alone.
• Peas: tall mangetouts will take the same support, though they prefer a cooler start.

Sow directly in May once frost has passed, four or five seeds per pot, then thin to the strongest. Keep them steadily moist and pinch out the growing tips when they reach the top of the obelisk to push energy into the pods. Start feeding with a high-potash tomato feed as soon as the first flowers open, and pick every couple of days — beans left to fatten on the vine stop producing.

Stack Herb Pots Into a Living Tower

Herbs are made for vertical growing because most of them are happy in shallow root runs. Build a tower from three pots of decreasing size, or use a fabric or plastic pocket planter hooked onto a wall. Put the sun-lovers at the top: rosemary, thyme, sage and oregano all want sharp drainage, so mix roughly seven parts peat-free multipurpose to three parts horticultural grit.

Below them, basil, parsley, coriander and chives will take slightly more moisture and a touch of shade at the roots. Keep mint in its own pot — it runs underground and will happily throttle everything else. Water the top pot until it runs through, then check the lower tiers with a finger; the bottom of a stack often stays damper than you expect.

Use Walls, Railings and Guttering

The vertical surfaces around you are free real estate. Wall planters fixed into brick or masonry with proper anchors can carry a surprising amount, but do the maths: a 60cm trough filled with wet compost weighs 15–20kg. Check the weight limit before you hang anything over a balcony railing, and always hang on the inside face where you can reach it.

• Guttering: a metre of guttering makes a fine shallow bed for cut-and-come-again lettuce, rocket and mizuna.
• Strawberries: four plants per metre of guttering, or in a wall basket where the fruit can dangle clear of damp compost.
• Trailing tomatoes: 'Tumbling Tom' and 'Maskotka' will cascade from a wall basket and crop well in a sunny spot.
• Salad troughs: 15cm of depth is enough for leaves; give strawberries 20cm.

Watering, Feeding and Keeping It All Upright

Small pots dry out alarmingly fast, and a vertical garden has more of them than most. Stand everything on saucers or drip trays, mix water-retaining granules into the compost, and top-dress with gravel to slow evaporation. In July and August, expect to water daily — twice on a hot day — and feed weekly, switching from a general-purpose feed to tomato feed once flowering begins.

For depth, add a little John Innes No.2 to your peat-free multipurpose; it gives structure that pure multipurpose lacks when a pot is tall. Refresh the top 5cm of compost each spring rather than repotting everything, and check ties and brackets after winter gales. A vertical garden is only as good as its fixings.

A Simple Sowing Calendar

• February to March: start tomatoes, chillies and basil on a bright windowsill indoors.
• April: sow hardy salad, radish and chard into their final troughs.
• May: beans go out once frost has passed, along with courgettes and outdoor basil.
• June to July: sow salad every three weeks for a continuous cut.
• September: lamb's lettuce, land cress and winter purslane keep the tower productive into autumn.

Start with one obelisk, one herb tower and a couple of wall planters, and you will be surprised how much a few square metres of balcony can produce.