Why a Balcony Is Made for Recycled Containers

A balcony is a tough little growing environment. It is windier than a garden, sunnier on a south-facing ledge, and the compost in a small pot can dry out before you have finished your morning tea. That is exactly why recycled containers suit it so well. They are free, they come in every size and shape, and because they are small you can shuffle them about as the seasons shift, moving tender pots into shelter and chasing the sun around the railings.

Old biscuit tins, wooden crates, colanders, chimney pots, dented watering cans and the teapot that lost its lid all make fine homes for herbs. Before you start collecting, though, think about weight. Wet compost is heavy, and balconies have load limits. Keep individual pots modest, spread them along the wall rather than stacking them all in one corner, and stand everything on saucers or trays so drips do not stain the balcony below.

Drilling, Lining and Cleaning Your Finds

Drainage is the single thing that decides whether a recycled pot works or turns into a swamp. Herbs, especially Mediterranean ones, rot quickly in waterlogged compost.

• Metal tins: turn upside down on a scrap of wood and punch three to five holes about 6mm across with a nail and hammer, or use a drill. File any sharp edges and give the inside a wipe of oil if rust bothers you.
• Wooden crates: line the sides with hessian, an old compost sack or a piece of fleece, then drill holes in the base. The lining holds compost in and lets excess water out.
• Teapots and china: ceramic is brittle, so use a tile drill bit at low speed and keep the bit wet. If you would rather not risk it, sit a small plastic pot inside and let the teapot act as a cachepot, with the drainage holes in the inner pot.
• Anything that held food: scrub with hot soapy water and rinse well. Old oil or tomato residue encourages mould and can hamper seedlings.

Terracotta and unglazed pots benefit from a soak in plain water before planting, so they do not steal moisture from the compost.

Compost, Drainage and Filling Up

Multipurpose compost is perfectly good, but herbs do better with extra air around the roots. Mix in roughly a quarter by volume of horticultural grit or perlite. Do not use garden soil on its own; it compacts in pots and brings in weeds and pests.

Put a thin layer of gravel or broken crocks in the base of larger containers to stop compost washing out through the holes. Fill to about 2cm below the rim so there is room to water without it running straight off. Stir in a handful of slow-release fertiliser or seaweed meal as you fill. Mediterranean herbs such as rosemary, thyme and oregano prefer leaner conditions, so go easy — rich compost gives you floppy, flavourless leaves.

What to Grow and Where to Put It

Group your pots with the tallest at the back against the wall, where they get shelter, and lower or trailing plants at the front. A rough planting plan for a modest balcony:

• Sunniest spot: rosemary, thyme, sage, oregano and marjoram in gritty compost. Thyme is happy in just 10–15cm of depth; rosemary wants nearer 30cm.
• Partial shade: mint, parsley, chives, chervil and lemon balm. Give mint its own tin — it spreads and will bully its neighbours.
• Quick crops: basil, coriander, rocket and cut-and-come-again salad leaves. Sow little and often, every three to four weeks from April to August, for a steady supply.
• Something pretty: nasturtiums trail beautifully from a crate and the flowers and leaves are both edible.

Supermarket herb pots can be split into three or four clumps and potted on individually — they will double in size within a fortnight.

Watering, Feeding and Everyday Care

Small containers on a windy balcony may need water twice a day in July. Water in the morning, at the base rather than over the leaves, and let the pot drain before it sits back in its saucer. If you are out at work, push a plastic bottle with a few pin holes in the lid, upside down, into the compost of larger pots as a slow drip feed.

Feed leafy herbs with liquid seaweed every fortnight through the growing season, and woody herbs about half as often. Pinch out the tips of basil, mint and parsley regularly to keep plants bushy and productive. Greenfly and whitefly are the usual pests; a firm blast of water from a spray bottle deals with most of them, and a squirt of dilute washing-up liquid in water helps with stubborn colonies.

Wind is the quiet killer. Group pots together so they shelter one another, and move anything tall or top-heavy away from the outer edge before a forecast gale.

Keeping It Going Through the Year

Start seeds indoors in March and harden them off in April once the worst of the frost has passed. Through summer, keep harvesting — herbs that are left to flower stop producing leaves, unless you want the seeds. In autumn, bring tender basil and coriander inside to a bright windowsill, and sow winter salad in a deep crate. Chives and mint will keep going indoors in a sunny kitchen spot, and a teapot on the sill makes a charming home for a small clump of either.

Over winter, most Mediterranean herbs go dormant. Cut back on watering, raise pots onto feet or stones so they never stand in cold water, and move them against a sheltered wall. Come March, top up the compost, refresh the mulch of grit, and your tins and crates will be ready to earn their keep all over again.