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Komatsuna (Japanese mustard spinach) seed packet front – mild leafy green vegetable seeds
Freshly harvested Komatsuna mustard spinach leaves prepared for cooking
Back of Komatsuna seed packet with sowing instructions and growing guidance
Young Komatsuna plants growing in neat rows with fresh green leaves
Side view of Komatsuna seed packet showing compact vegetable seed format

Komatsuna Seeds

Brassica rapa var. perviridis

Komatsuna seeds grow into delicious mustard spinach. Sometimes referred to as Japanese mustard spinach, it is milder than the average mustard leaf, yet this variety with its white stems and thick leaves is filled with goodness and the delicious mustard taste without the spicy reputation.

Approx 300 seeds

  • Grow Your Own
  • Micro Green
  • Tolerates Most Light
  • Low Maintenance

Komatsuna Seeds – Quick Growing Guide

Komatsuna seeds produce tender, mild mustard greens ideal for salads and stir-fries. Sow from March to September, either directly outdoors or in pots. These Japanese mustard spinach seeds thrive in cool weather and mature quickly, making them a rewarding choice for gardeners seeking unusual vegetable seeds.

How to Sow, Grow and Harvest Komatsuna Seeds

  • Sow:Jan–Oct
  • Germination:5–10 days
  • Grow:In fertile, well-drained soil with partial to full sun
  • Water:Keep soil consistently moist but not waterlogged
  • Harvest:Pick leaves young for best flavour, from 30 days after sowing
  • Best for:Pots, beds, windowsills

Grow in Your Garden

Komatsuna Seeds – Mild Mustard Spinach for Your Garden

Calendar

Komatsuna Seeds planting calendar: Jan–Oct: Sow • May–Nov: Flowers or harvest

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
SowFlowers / Harvest

How to Grow

Komatsuna seeds can be sown outdoors from January through October, thriving in containers, balconies, or garden beds where the soil is fertile and well-prepared. This mild mustard spinach prefers a pot size of around 50 cm to develop tender, flavorful leaves with minimal effort.

  • Sowing

    Sow Komatsuna seeds thinly into small holes on firm, fertile soil and cover lightly. Keep the soil consistently moist to encourage reliable germination during the sowing months of January to October.

  • Growing

    Once seedlings emerge, thin them to avoid overcrowding, allowing enough space for healthy growth within a 50 cm container or garden bed. This biennial plant benefits from regular spacing to ensure the tender greens develop fully from May through November.

  • Plant care

    Maintain consistent moisture by watering regularly, especially during warmer months, to keep the soil evenly damp but not waterlogged. Harvest young leaves frequently by cutting back to encourage continuous growth, ensuring a steady supply of mild mustard greens throughout the growing season.

About Komatsuna

Easy to grow, versatile for salads or cooking, ideal for pots or garden beds, mild mustard flavour, unusual and nutritious vegetable variety.

  • Grow Your Own
  • Micro Green
  • Tolerates Most Light
  • Low Maintenance

Eventual height & spread

0.45m
0.6m
Plant

History of Komatsuna

The name 'Komatsuna' means 'greens of Komatsu' in Japanese, named after Komatsugawa village near Tokyo. It was popularised by Tokugawa Yoshimune, the eighth shogun, who enjoyed it during a visit to the area.

Other NamesMustard spinach, Japanese mustard spinach and Tender greens.
Pet/Baby SafeNon-toxic

FAQs

Reviews

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Elsewhere in the range

Recent reviews of other Herboo seeds. These are not ratings of Komatsuna Seeds.

26 Aug 2026

Can't go wrong with Cosmos

Lovely packet of seeds, bought one for me and one as gift :)

Gareth
20 Aug 2026

Good card gifts

Bought a couple of these as card gifts for friends and they loved them

Flavia
12 Mar 2026

Good tips

Liked how you gave tips on how best to sow. nicely done

Joel C.