How to Grow Giant Mizuna

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Giant Mizuna

Brassica rapa var. nipposinica

vegetable

Giant mizuna is a Japanese mustard green with delicate, feathery, deeply cut leaves that grow larger than standard mizuna varieties. The frilly foliage is tender and mildly peppery, excellent for salads, stir-fries, and Asian cuisine. This cool-season brassica is fast-growing and prolific, providing multiple harvests throughout the season.

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Example Giant Mizuna timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Giant Mizuna

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Giant Mizuna

    Around May 27

    ≈ 40 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Giant Mizuna dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade; 5-6 hours of direct sunlight daily. Afternoon shade beneficial in hot climates to prevent bolting.
💧
Water: Keep soil consistently moist but not waterlogged. Water deeply 2-3 times per week; increase frequency in hot weather. Drought stress causes early bolting and bitter flavor.
📏
Spacing: 6 inches
📅
Days to maturity: 40-50 days for first harvest; continues producing for 60-90 days
🌱
Planting depth: 0.25

Soil

Type: Well-draining loamy soil, rich in organic matter
pH: 6.0-7.5
Amendments:
Compost Aged manure Organic matter Balanced fertilizer (10-10-10)

Growing Zones

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Thrives in zones 3-9; prefers cool seasons for best flavor and texture

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b

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Growth Stages

1

Seedling

7-10 days

Tiny cotyledons emerge with delicate true leaves beginning to show feathery characteristics. Plants are vulnerable and fragile.

Keep soil consistently moist. Provide bright light to prevent leggy growth. Thin seedlings to proper spacing when first true leaves appear. Protect from strong winds and direct intense heat.

2

Vegetative (Early Growth)

14-21 days

Rapid leaf development with characteristic feathery, finely-cut foliage becoming more pronounced. Plant establishes deep root system.

Thin to 6-inch spacing for full-sized plants. Maintain consistent moisture and cool temperatures. Begin light harvesting of outer leaves if desired. Watch for flea beetle damage on young leaves.

3

Full Growth/Maturation

14-21 days

Plant reaches 12-18 inches tall with abundant, fully-developed frilly leaves. Dense rosette of tender greens ready for primary harvest.

Begin regular harvesting of outer leaves to encourage bushiness. Maintain consistent watering. Monitor temperatures; provide afternoon shade if temperatures exceed 75°F to prevent bolting. Fertilize every 2-3 weeks with balanced fertilizer.

4

Peak Production

21-30 days

Plant at full size producing maximum leaf volume. Leaves remain tender and flavorful if cool temperatures maintained.

Harvest frequently by cutting outer leaves or entire plant 2 inches above soil line. Cut-and-come-again harvesting extends productivity. Keep soil consistently moist. Bolting risk increases; prioritize harvest before flowering.

5

Bolting/End of Season

Variable

Plant produces central flower stalk; leaves become tougher, more bitter, and less desirable. Yellow flowers appear if plant is allowed to mature fully.

Once bolting begins, plants are best removed and composted. If warmer weather triggers bolting, plant new succession crops for fall harvest in most climates. In cool regions, some growers allow bolting for seed saving.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Brassicas (cabbage, broccoli, cauliflower, kale) Tomatoes Fennel Pole beans

Common Pests

  • Use row covers during seedling stage. Apply neem oil or spinosad spray. Introduce beneficial insects like parasitic wasps. Companion plant with catnip or tansy.

  • Handpick caterpillars daily. Use Bt (Bacillus thuringiensis) spray. Maintain row covers. Encourage natural predators like parasitic wasps and birds.

  • Spray with strong water stream to dislodge. Use insecticidal soap or neem oil. Release ladybugs or lacewings. Reflective mulches may deter infestation.

  • and

    Remove by hand in early morning or evening. Use beer traps or copper tape barriers. Encourage natural predators like ground beetles. Diatomaceous earth application.

  • Use yellow sticky traps to monitor and control. Spray with neem oil or insecticidal soap. Increase air circulation. Remove heavily infested leaves.

Uses

🍳

Fresh salads and raw consumption

Culinary

The delicate, feathery leaves are perfect for fresh green salads, providing a mild peppery flavor and attractive presentation. The tender texture requires no cooking and is at its best when harvested young and chilled. [source]

🍳

Asian cuisine and stir-fries

Culinary

Giant mizuna is traditionally used in Japanese cooking, particularly in stir-fries, soups, and hot pots where the leaves wilt slightly but retain structure. Its mild mustard notes complement Asian flavors and cooking techniques. [source]

🍳

Microgreens and garnish

Culinary

Young mizuna leaves serve as attractive, flavorful microgreens and garnishes for plated dishes, salads, and Asian-inspired cuisine. The feathery appearance adds visual interest to culinary presentations. [source]

💊

Nutritional and antioxidant benefits

Medicinal

Mizuna contains glucosinolates and other phytonutrients with potential cancer-fighting properties, along with vitamins A, C, and K. As a brassica, it provides anti-inflammatory compounds and supports digestive health. [source]

🦋

Pollinator support

Wildlife

When allowed to flower, mizuna provides early-season nectar and pollen for bees and other pollinators. The bright yellow flowers are attractive to beneficial insects. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begin harvesting outer leaves when plants are 6-8 inches tall, cutting 2 inches above soil line for regrowth (cut-and-come-again method). For full plant harvest, cut entire plant at soil level when 12-18 inches tall. Harvest in morning for crispest texture and best flavor. Continue harvesting before bolting begins; cool-season timing is essential. In mild climates, plant fall crops for winter harvest when flavor and texture are optimal. Giant mizuna is most tender when harvested young; older leaves become more peppery and potentially tougher.

Fun Facts

  • 🌱 Giant mizuna originates from Japan where it has been cultivated for centuries, with 'mizuna' literally meaning 'water vegetable' in Japanese due to its preference for consistent moisture.
  • 🌱 The deeply cut, feathery leaves of mizuna are formed through a natural genetic trait that maximizes surface area for photosynthesis while maintaining tenderness, making it more delicate than its non-feathery brassica relatives.
  • 🌱 Mizuna can regrow multiple times after cutting if harvested properly at the base, with a single planting sometimes producing harvestable greens for 2-3 months in cool conditions.

Gardening Terms

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