A head of Spinach Mustard "Old Tokyo" Komatsuna with a wooden box of vintage Japanese pictures.
A couple of heads of Spinach Mustard "Old Tokyo" Komatsuna with a wooden box of pictures.
Large leaves from Spinach Mustard "Old Tokyo" Komatsuna with a large Japanese knife on a grey background.
Spinach Mustard "Old Tokyo" Komatsuna leaves and chopped stems in a bowl on a grey background.
Cooked and raw Spinach Mustard "Old Tokyo" Komatsuna with Japanese props.
A head of Spinach Mustard "Old Tokyo" Komatsuna with a wooden box of vintage Japanese pictures.
A couple of heads of Spinach Mustard "Old Tokyo" Komatsuna with a wooden box of pictures.
Large leaves from Spinach Mustard "Old Tokyo" Komatsuna with a large Japanese knife on a grey background.
Spinach Mustard "Old Tokyo" Komatsuna leaves and chopped stems in a bowl on a grey background.
Cooked and raw Spinach Mustard "Old Tokyo" Komatsuna with Japanese props.

Komatsuna Seeds,
Spinach Mustard "Old Tokyo"

4.954 Reviews#OR169 · 200 seeds
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Description

(Brassica rapa var. perviridis). It’s hard to believe this is truly a mustard, because the flavor is so mild, sweet, and spinach-like—but that’s exactly what makes old Tokyo komatsuna such a standout. This traditional Japanese strain blends the best parts of spinach and mustard into one juicy, tender green that’s long revered in Japanese, Taiwanese, and Korean cooking. Exceptionally rich in vitamins A and C, along with vitamin K, folate, calcium, and iron, it has earned its place as one of the most underrated leafy greens around. Mouth-watering, highly nutritious, and endlessly useful in the kitchen, it’s a classic that deserves a lot more love.

Plant Details

Botanical Name
Brassica rapa var. perviridis
Life Cycle
Annual
Sun Requirement
6–12 hr.
Days to Germinate
5–8
Days to Maturity
45–50
Planting Depth
¼ in.
Plant Spacing
12 in.
Ideal Temperature
55–70°F
Frost Hardy
Yes

Growing Guide

When to Grow

Plant Komatsuna in early spring as soon as the soil can be worked or in late summer for a fall crop. For those in colder regions or USDA zones with freeze dates, plant about 2-3 weeks before the last expected spring freeze or 6-8 weeks before the first expected fall freeze. Check local frost/freeze dates for precise timing.

How to Sow and Plant

Direct sow seeds 1/4 inch deep, spaced 1 inch apart in rows about 12 inches apart. Thin seedlings to 6–12 inches apart once they have a few true leaves. Alternatively, start seeds indoors 4–6 weeks before transplanting.

How to Grow

Komatsuna grows best in full sun but tolerates partial shade, requiring 6–12 hours of sun daily. Water regularly, especially during dry spells. Fertilize with a balanced organic fertilizer or compost tea every few weeks. Harvest leaves when they are young and tender for the best flavor, usually around 25–30 days after sowing for baby greens or later for mature greens.

How to Save Seeds

To save the seeds, allow pods to brown, dry, and become crispy. Shake pods into a paper bag to remove the seeds. Store seeds in a cool, dark, dry location.

FAQ

Can Komatsuna be grown indoors?

Yes, it can be grown in containers indoors with adequate light.

How often should I water Komatsuna?

Water regularly to keep the soil evenly moist but not soggy.

Is Komatsuna prone to pests?

It can be affected by common brassica pests like aphids and flea beetles. Use row covers and organic pest control methods as needed. Change locations each year to help reduce pest occurrence.

Browse our full range of bok choy and tatsoi seeds.

Customer reviews

4.9 / 5 54 Reviews

What gardeners are saying

  • Mild spinach-mustard flavor: Tastes like spinach with a soft mustard note, tender raw or cooked.

  • Fast, easy start: Sprouts in a few days from direct sowing and grows quickly.

  • Frost hardy: Overwinters and shrugs off hard freezes with little leaf damage.

  • Slow to bolt: Keeps producing through 85 to 90 degree days when other greens bolt.

  • Big, prolific leaves: Leaves grow huge; cut the outer ones and the plant keeps coming.

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