How to help your veg plot off to a flying start this April.

How to help your veg plot off to a flying start this April.


April is a fantastic month for sowing vegetable seeds as the soil warms and daylight increases. Here's a comprehensive guide to what you can sow this month, organised by location (windowsill, greenhouse, polytunnel, and direct sowing outside). We’ve included germination temperatures and practical tips to help you succeed.


Seeds to Sow on the Windowsill

Great for early starts when outdoor conditions are still unreliable.

  • Tomatoes (18–21°C)
    Your last chance to sow tomatoes. Sow in small pots, keep in a warm, sunny spot, and transplant when large enough to handle. Avoid overwatering to prevent damping off.

  • Chillies & Peppers (20–25°C)
    Sow early April as they need a long time to grow before they produce fruit, These need warmth to germinate. Use a propagator if possible and pot on once seedlings develop true leaves.

  • Herbs

    • Basil (20–25°C): Needs consistent warmth; keep near a sunny window.
    • Coriander & Parsley (18–20°C): Soak seeds overnight to improve germination.

Tips: Rotate trays to ensure even growth and prevent seedlings from becoming leggy.


Seeds to Sow in the Greenhouse or Polytunnel

Protected environments allow for earlier sowing of tender crops.

  • Cucumbers (21–25°C)
    Sow in pots and keep warm until seedlings appear. Avoid waterlogging.

  • Courgettes, Marrows, and Pumpkins (18–20°C)
    Sow one seed per pot for easy transplanting later.

  • Aubergines (20–25°C)
    Require warmth and good light. Prick out when seedlings are strong.

  • Lettuce (10–15°C)
    Sow in modules for transplanting. Avoid overcrowding to reduce disease risks.

  • Melons (21–25°C)
    Ideal for polytunnels; sow in pots and keep at consistent warmth.

Tips: Ensure good ventilation to prevent fungal diseases. Use fleece or bubble wrap for additional warmth on cold nights.


Seeds to Sow Directly Outside

April’s warming soil makes it perfect for sowing hardier vegetables outdoors. Aim for soil temperatures of at least 10°C.

  • Carrots (12–18°C)
    Sow thinly in well-drained soil. Avoid stony ground to prevent forked roots.

  • Beetroot (10–15°C)
    Sow in rows, spacing seeds well apart. Water consistently to prevent woody roots.

  • Parsnips (10–15°C)
    Germination can take 2–3 weeks. Mark rows with fast-growing radish seeds for visibility.

  • Radishes (10–18°C)
    Quick to germinate and harvest. Perfect for intercropping.

  • Spinach (10–18°C)
    Sow in shallow drills. Choose bolt-resistant varieties if the weather turns warm.

  • Peas (10–15°C)
    Sow directly or under cloches if the soil is still cold. Protect from birds with netting.

  • Broad Beans (10–15°C)
    Sow in double rows for stability. Pinch out tips later to deter blackfly.


Additional Tips for April Sowing

  • Soil Preparation:

    • Rake soil to a fine tilth for small seeds. Add organic matter to improve fertility.
    • Warm soil with cloches or fleece if temperatures are low.

  • Germination Tips:

    • Monitor soil temperature with a thermometer; seeds won’t germinate well if it’s too cold.
    • Avoid sowing into waterlogged soil to prevent seeds from rotting.

  • Successional Sowing:

    • Stagger sowings every few weeks for a continuous harvest throughout the season.

  • Frost Protection:

    • Cover young plants with cloches, fleece, or tunnels during cold snaps.

April is a month of opportunity for UK gardeners. With the right preparation and care, you'll set the stage for a productive growing season. 
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