PlantyBoxPot and soil
At least 30-40 litres (8-10 gallons) per plant; cherry tomatoes manage with 20 litres (5 gallons). Use rich potting mix and a drainage layer. On balconies pick compact or determinate varieties (cherry, grape, 'patio' types) and add a 1-1.5 m stake from day one.
Light and position
Full sun, 6-8 hours a day: with less light you get leaves but little fruit. Plant out when nights stay above 12 °C (54 °F).
Watering
Regularly, about every 2 days, daily in hot weather or small pots, always at the base. Consistency matters more than quantity: soil swinging from dry to soaked causes split fruit and blossom end rot.
Feeding
Roughly every 10 days from flowering on, with a potassium-rich feed (tomato or fruiting-plant fertilizer). Before flowering a balanced feed is enough.
Harvest
Fruit fully and evenly coloured, giving slightly when pressed.
How to harvestTwist the fruit off with its stalk. Picked when just turning, they ripen indoors.
Common problems
Not a disease: a calcium shortage caused by irregular watering. Water consistently and mulch the pot.
A big watering or a storm after dry days. Again, the fix is regular watering.
Often blight, encouraged by humidity. Remove affected leaves, water only the soil and keep air moving between plants.
FAQ
How big a pot do tomatoes need?
At least 30-40 litres (8-10 gallons) for a regular plant, 20 litres (5 gallons) for a cherry tomato. In small pots they go thirsty and crop poorly.
Should I remove tomato suckers?
On indeterminate (vining) varieties, yes: pinch out the shoots between stem and leaf so the plant puts its energy into fruit. Compact varieties don't need it.
When should I pick tomatoes?
When the colour is full and even and the fruit gives slightly when pressed. Picked a little early, they finish ripening indoors.
