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How to germinate Nasturtium seeds

by Mark Foley on
Spring Flower seeds Nasturium

Stepbystep guide to germinating nasturtium seedsStep 1 Prepare containers and compostUse pots or trays with drainageFill with light freedraining compo-1

How to germinate nasturtium seeds

Nasturtiums are fast-growing, easy flowers known for their bright blooms and edible leaves. They are one of the simplest seeds to germinate, making them ideal for beginners and quick results.

They grow well in borders, containers, and even poorer soils.

Quick answer: how to germinate nasturtium seeds

To germinate nasturtium seeds, sow them 1–2cm deep in moist compost, keep them at 15–20°C, and water lightly. Seeds usually germinate within 7–14 days.

Step-by-step guide to germinating nasturtium seeds

Step 1: Prepare containers and compost

  • Use pots or trays with drainage
  • Fill with light, free-draining compost
  • Avoid overly rich soil

Step 2: Soak seeds (optional but helpful)

  • Soak seeds in water for 6–12 hours
  • Helps soften the hard outer shell
  • Improves germination speed

Step 3: Sow the seeds

  • Sow seeds 1–2cm deep
  • Space them well to allow growth
  • Cover with compost

Step 4: Water gently

  • Water after sowing
  • Keep compost evenly moist, not wet
  • Avoid overwatering

Step 5: Provide warmth and light

  • Keep at 15–20°C
  • Place in a bright location
  • Move to strong light once seedlings appear

When nasturtium seeds germinate

Nasturtiums typically germinate:

  • Within 7–14 days
  • Faster in warm conditions
  • Slower in cooler temperatures

They are reliable and quick to establish.

Best nasturtium varieties

  • Trailing nasturtiums
    • Ideal for hanging baskets and edges
  • Bush varieties
    • Compact and tidy
    • Great for containers
  • Climbing types
    • Can be trained up supports

Choose based on space and growing style.

Ideal conditions for germination

  • Temperature
    • 15–20°C consistently
  • Light
    • Not essential for germination
    • Important after sprouting
  • Soil
  • Water

Common problems

Seeds not germinating

  • Cause: cold soil or lack of moisture
  • Fix: increase warmth and maintain moisture

Rotting seeds

  • Cause: overwatering
  • Fix: reduce watering and improve drainage

Leggy seedlings

  • Cause: lack of light
  • Fix: move to a brighter position

Mould on soil

  • Cause: excess moisture
  • Fix: improve airflow

Climate and regional notes

UK & Ireland

  • Can be started indoors or direct sown
  • Very reliable in spring and summer

Europe

  • Grows well across most regions
  • Earlier sowing possible in warmer areas

USA

  • Commonly direct sown after frost
  • Thrives in a range of climates

Pro tips for better germination

  • Soak seeds for faster results
  • Avoid overly rich soil (reduces flowering)
  • Sow directly where possible to avoid disturbance
  • Thin seedlings if overcrowded
  • Keep watering consistent

FAQs: germinating nasturtium seeds

How long do nasturtium seeds take to germinate
Usually 7–14 days in suitable conditions.

Should I soak nasturtium seeds before planting
Yes, it can improve germination speed.

Do nasturtium seeds need light to germinate
No, they should be covered with soil.

Can I sow nasturtiums directly outdoors
Yes, they are ideal for direct sowing.

Why are my nasturtium seeds not germinating
Usually due to cold soil or inconsistent moisture.

How often should I water nasturtium seeds
Keep soil consistently moist but not waterlogged.

Can nasturtiums grow in pots
Yes, especially bush varieties.

Do nasturtiums need rich soil
No, they often flower better in poorer soil.

When should I transplant seedlings
When they are strong enough, but they prefer minimal disturbance.

Are nasturtiums easy to grow
Yes, they are one of the easiest plants from seed.

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