How to Grow Nasturtium from Seed (Easy Step-by-Step Guide)

Growing nasturtium from seed is one of the easiest and most rewarding ways to add colour, edible flowers, and wildlife value to your garden. Nasturtiums are fast-growing, low-maintenance plants that thrive in UK conditions and are perfect for beginners, pots, borders, hanging baskets, and allotments.

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Nasturtiums are cheerful, edible flowers with bright colours and peppery taste — easy to grow in beds, containers, and hanging baskets.

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This guide explains exactly how to grow nasturtiums from seed, from sowing and planting to care and harvesting.


Why Grow Nasturtiums from Seed?

Nasturtiums are ideal seed-grown plants because they:

  • Germinate quickly
  • Grow fast with minimal care
  • Flower for months
  • Thrive in poor soil
  • Are fully edible
  • Attract pollinators

They also dislike root disturbance, so growing from seed gives the strongest, healthiest plants.


When to Grow Nasturtium from Seed (UK)

Nasturtiums are frost tender, so timing matters.

  • Sow indoors: March to April
  • Sow outdoors: Late April to May
  • Flowering: June to October

Outdoor sowing should only be done once all risk of frost has passed.


How to Sow Nasturtium Seeds Indoors

Starting indoors gives earlier flowers.

You will need:

  • Nasturtium seeds
  • Small pots (one seed per pot)
  • Multipurpose compost

Steps:

  1. Fill pots with compost
  2. Sow one seed per pot
  3. Push seed about 2cm deep
  4. Water gently
  5. Place in a bright, frost-free spot

Seeds usually germinate in 7–14 days.

Harden seedlings off gradually before planting outside.


How to Sow Nasturtium Seeds Outdoors

Direct sowing is simple and works very well.

Steps:

  1. Choose a sunny position
  2. Ensure soil is warm and free-draining
  3. Sow seeds 2cm deep
  4. Space seeds 20–30cm apart
  5. Water lightly

Protect young seedlings from slugs.


Should You Soak Nasturtium Seeds?

Soaking is optional but helpful.

  • Soak seeds in water for 8–12 hours
  • Softens the hard seed coat
  • Can speed up germination

Do not soak longer than 24 hours.


Best Place to Grow Nasturtiums

Nasturtiums grow best in:

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March is when the growing season truly begins. Seeds are being sown daily, beds are prepared and late frosts are still possible — these essentials help produce strong plants and a successful start.

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  • Full sun
  • Free-draining soil
  • Poor to moderately fertile ground

Avoid rich soil and fertiliser — too much nutrition causes leafy growth and fewer flowers.

They grow well in:

  • Pots and containers
  • Hanging baskets
  • Raised beds
  • Borders
  • Allotments

Watering Nasturtiums

  • Water regularly while plants establish
  • Once established, water sparingly
  • Avoid waterlogged soil

Nasturtiums are drought tolerant once settled.


Do Nasturtiums Need Feeding?

No. Nasturtiums do not need fertiliser.

  • Feeding reduces flowering
  • Poor soil produces better blooms

If grown in pots, a very light feed may be used sparingly, but it is usually unnecessary.


How Long Do Nasturtiums Take to Flower?

Nasturtiums usually flower:

  • 8–10 weeks after sowing

Warm weather speeds growth significantly.


Deadheading and Ongoing Care

To keep nasturtiums flowering:

  • Remove faded flowers regularly
  • Pick flowers often
  • Avoid letting seeds form too early

This encourages continuous blooming.


Do Nasturtiums Self-Seed?

Yes. If flowers are left to set seed:

  • Seeds drop naturally
  • New plants may appear the following spring

This can make nasturtiums seem perennial.


Common Problems When Growing Nasturtiums from Seed

Lots of leaves, few flowers

  • Soil too rich
  • Overfeeding

Poor germination

  • Soil too cold
  • Seeds planted too early

Weak growth

  • Too much shade
  • Overwatering

Are Nasturtiums Good for Beginners?

Absolutely. Nasturtiums are one of the best plants for beginner gardeners.

They:

  • Grow quickly
  • Need minimal care
  • Are forgiving of mistakes
  • Produce edible leaves and flowers

They are also great for children and first-time gardeners.


Final Thoughts: Growing Nasturtium from Seed

Growing nasturtium from seed is simple, reliable, and hugely rewarding. With minimal effort, you’ll enjoy months of bright flowers, edible leaves, and pollinator activity. Whether grown in pots, borders, or hanging baskets, nasturtiums prove that great garden results don’t need complicated techniques.


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