How to Grow Tomatoes

Tomatoes are the heart of the summer greenhouse and allotment — vibrant, productive, and full of flavour. They need warmth, light, and regular feeding, but are easy to grow once you master the rhythm of sowing, planting, and pinching.

You can grow:

• Cordon (indeterminate) – tall, single-stemmed types for greenhouses or outdoors.

• Bush (determinate) – compact, good for pots or raised beds.

• Cherry – sweet, small fruits ideal for snacking.

🗓️ Month-by-Month Growing Guide (UK)

January

🧤 Plan & Prepare

• Choose your varieties:

  • ‘Gardener’s Delight’ (cherry)

  • ‘Alicante’ (classic medium)

  • ‘Moneymaker’ (reliable all-rounder)

  • ‘Roma’ (plum for sauces)

• Clean pots, trays, and greenhouse glass.

• Prepare a warm, sunny sowing space (windowsill, propagator, or heated greenhouse).

February

🌱 Early Sowing Indoors

• Sow seeds in trays or modules at 18–21°C (heated propagator).

• Cover lightly with compost and mist with water.

• When seedlings appear, move to a bright, frost-free spot.

• Avoid overwatering.

March

🌿 Main Sowing Month

• Sow main batches indoors or under cover.

• When seedlings have 2–3 true leaves, pot on into individual small pots.

• Keep warm (ideally 16–18°C).

• Turn plants regularly so they grow straight.

April

🌾 Potting On & Preparation

• Pot on again as roots fill pots — into 9 cm (3½”) pots.

• Harden off greenhouse-sown plants on mild days.

• Prepare outdoor beds or greenhouse soil:

  • Dig in compost or well-rotted manure.

  • Add tomato fertiliser or bonemeal.

• Build stakes or string supports for cordon varieties.

May

☀️ Plant Out & Early Training

• When frost risk has passed (mid–late May):

  • Greenhouse: transplant to final pots, grow bags, or borders.

  • Outdoors: plant out after hardening off for 7–10 days.

• Space 45 cm apart, 75 cm between rows.

• Tie stems to canes or strings for support.

• Water deeply to settle in.

• Mulch around the base to retain moisture.

June

🍃 Growth & Training

• Tomatoes grow fast now.

• Pinch out side shoots (in leaf axils) on cordon types weekly.

• Keep soil moist — water at the base, not the leaves.

• Feed every 10–14 days with a high-potash tomato fertiliser.

• Open greenhouse vents for airflow.

July

🍅 Flowering & Fruit Setting

• Continue feeding and watering consistently.

• Tap flowers gently to help pollination.

• Tie new growth to supports as it lengthens.

• Remove lower leaves to improve airflow and ripening.

• Watch for pests like aphids or whitefly — use natural deterrents.

August

☀️ Ripening Time

• Keep feeding and watering regularly — never let roots dry out.

• Remove yellowing leaves and excess foliage.

• Pinch out the main growing tip (after 5–6 trusses of fruit) — this directs energy to ripening.

• Harvest as fruits ripen — the more you pick, the more you’ll get.

September

🍂 Final Ripening & Harvesting

• Continue picking ripe fruit.

• For green tomatoes:

  • Move them indoors to ripen on windowsills.

  • Or store with a ripe banana to encourage ripening.

• Remove diseased or spent plants.

• Compost healthy remains.

October

🌾 Clear & Compost

• Pull up old plants after final harvest.

• Disinfect pots and greenhouse surfaces.

• Add compost or manure to the bed for next year.

• Save seeds from the best fruits (ferment and dry before storing).

November–December

🪴 Rest & Plan

• Enjoy preserved or frozen tomatoes.

• Plan varieties and rotations for next year.

• Check your greenhouse structure and clean glazing for maximum winter light.

🌼 Key Growing Tips

• Sun: Full sun, sheltered position.

• Soil: Rich, well-drained, high in organic matter.

• Watering: Deep, steady watering — avoid wetting foliage.

• Feeding: Every 10–14 days once flowers appear.

• Support: Canes or strings for tall types.

• Pests: Watch for aphids, whitefly, and blight.

🌤 Tip of the Season

“Regular watering and picking are the secrets to sweet, flawless tomatoes — consistency is everything.”