How to grow tomatoes in the UK
Choose the right type
In the UK, tomatoes need warmth. Cordons (indeterminate) suit greenhouses and sunny south-facing walls; bush (determinate) and trailing types suit pots outdoors in milder areas. For cool summers or Scotland, prefer early outdoor varieties or grow under glass/polytunnel.
UK month-by-month timings
| Month | What to do |
|---|---|
| Feb–Mar | Sow indoors in a heated propagator or warm windowsill (greenhouse crops often mid–late Feb; outdoor types March). |
| Apr | Pot on into 7–9 cm pots; keep frost-free, bright, and not sodden. |
| May | Harden off after last frost risk. Plant greenhouse crops when night temps stay above ~10°C. |
| Late May–Jun | Plant outdoors only once nights are reliably mild (often early June in the north). |
| Jun–Aug | Water regularly, feed when fruit set, remove side shoots on cordons, ventilate greenhouses. |
| Sep–Oct | Pinch growing tips; ripen remaining fruit indoors if frost threatens. |
Sowing and potting on
Sow 2–3 seeds per small pot or module in peat-free seed compost, cover lightly, and germinate at about 18–21°C. Thin to the strongest seedling. Pot on when roots fill the pot and plants are sturdy, not spindly — stretchy stems usually mean insufficient light.
Planting out
Plant deeply (burying the stem a little encourages extra roots). Space bush plants about 45 cm apart; cordons 40–50 cm with a cane or string. Use rich, moisture-retentive soil or quality grow bags. Stake immediately.
Care, feeding, problems
- Water evenly — boom-and-bust watering worsens blossom end rot and splitting.
- Feed with a high-potash tomato fertiliser once first fruits set.
- Cordons: Pinch out side shoots in leaf axils; stop the plant after 4–6 trusses outdoors (more under glass if season allows).
- Blight: Outdoor plants are vulnerable in warm, wet summers. Improve airflow; remove infected leaves promptly; greenhouse crops are safer.
Harvest
Pick when fully coloured and slightly soft. Green end-of-season fruit ripens in a warm indoor tray, optionally with a ripe banana to speed ethylene. Expect meaningful harvests from July (under glass) through September outdoors in a good year.