Spinach vs Komatsuna

What's the difference between spinach and komatsuna?

They look similar and sit side by side at Japanese grocery stores, but spinach and komatsuna have distinct differences in nutrition, taste, and ease of use. Let's compare them with data.

Nutrition (per 100g)

Nutrient Spinach Komatsuna
Calories 18kcal 13kcal
Protein 2.2g 1.5g
Fiber 2.8g 1.9g
Vitamin C 35mg 39mg
Iron 2mg 2.8mg
Calcium 49mg 170mg
Potassium 690mg 500mg
Beta-carotene 4200μg 3100μg
Folate 210μg 110μg

Source: Standard Tables of Food Composition in Japan (8th ed.) 2020

Price Comparison

Spinach

¥1,138/1kg

Annual average (2026)

Komatsuna

Retail price data not available

Peak Season

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Storage & Flavor

Spinach

Flavor

Has a characteristic slight bitterness and astringency, but sweetness increases with winter cold exposure. Rich in iron and other nutrients

Shelf Life

3-4 days refrigerated, 1 month frozen (blanched)

How to Select

Choose spinach with thick, vibrant deep-green leaves. Firm, thick stems and a reddish tinge at the root base indicate extra sweetness

Komatsuna

Flavor

Milder and less bitter than spinach. The stems are crisp and the leaves tender. Highly nutritious, with about two-and-a-half times more calcium than spinach

Shelf Life

3-4 days refrigerated, 1 month frozen (blanched)

How to Select

Choose bright green, firm leaves and thick, sturdy stems. Select bunches that are plump throughout, with no wilting or yellowing

Verdict

Choose spinach for iron, folate, and beta-carotene. Choose komatsuna for calcium and convenience (no blanching needed). Both are excellent — use them based on the dish.

FAQ

Does spinach need to be blanched?

Yes. Spinach is high in oxalic acid, so it should be briefly boiled and rinsed. Komatsuna has much less oxalic acid and doesn't require blanching — it can even be eaten raw.

Does komatsuna really have more calcium?

Yes. Komatsuna has 170mg/100g vs spinach's 49mg — about 3.5x more. A natural pick for anyone paying attention to calcium intake.

Which freezes better?

Both freeze well after blanching (about 1 month). Komatsuna can even be frozen raw without blanching, giving it a slight edge in convenience.