Growing tomatoes on a balcony

The most common reason balcony tomatoes fail is not the wrong variety — it is too little sun and too small a pot. Tomatoes are sun-lovers, needing at least six hours of direct light a day before they will flower and set fruit, and no amount of feeding will make up for a shaded balcony.

Pots and growing medium

For a home balcony, choose a small-fruited or cherry variety; the root system is more modest and suits a ten to fifteen litre pot. Use a peat-based mix with perlite for drainage. Waterlogging at the bottom of the pot, and the root rot that follows, is what kills more balcony tomatoes than anything else.

Watering rhythm

Tomatoes dislike swinging between bone dry and soaking. Let the surface of the soil dry, then water thoroughly. During fruiting this matters most: erratic watering is what splits the fruit. Watering early in the morning beats watering at dusk, as it leaves less overnight humidity for disease to take hold in.

Staking and side shoots

Stake the plant once it reaches about thirty centimetres, before the weight of fruit can snap a stem. Tomatoes throw out side shoots from every leaf axil continuously; unless you deliberately want a bushier plant carrying more but smaller fruit, pinch them out regularly so the plant's energy goes into the main stem and the fruit it is already carrying.