Image source: Depositphotos.com

Overview

• Name: Mizuna (Japanese Mustard Greens)
• Botanical Name: Brassica rapa var. nipposinica or Brassica rapa var. japonica
• Plant Family: Brassicaceae (mustard family)
• Native to: East Asia (primarily Japan and China)

Description

Mizuna is a cool-season leafy green with ling, thin, crip, upright growing stems and finely serrated, feathery leaves that form dense rosettes. There are several varieties of mizuna with different colored stems and leaves, including light green stems with darker green leaves, purple stems and green leaves, or green stems and dark purple leaves. The leaves have a mild mustard flavor, somewhat similar to arugula (rocket) but less peppery. Although mizuna is technically a mustard, its flavor is so mild that it is used as salad leaf green in salad mixes.

Plants generally reach 20–35 cm (8–14 in) in height and can spread similarly wide when grown to maturity. Under favorable conditions, mature mizuna plants may produce small, yellow, four-petaled flowers typical of the Brassicaceae family. If allowed to set seed, slender pods (siliques) follow. While often cultivated as an annual for baby greens or full-sized leaves, mizuna in milder climates can behave like a short-lived biennial, bolting once day lengths extend and temperatures rise.

Interesting Facts

• Mizuna has been a staple in Japanese cuisine for centuries, commonly used in soups, salads, and pickled dishes. Samurai were said to enjoy it for its invigorating taste and reputed health benefits. Over time, it spread to Western markets as consumers sought diverse leafy greens with mild, peppery flavors.
• The name “mizuna” can be translated from Japanese to mean “water greens,” referencing its high water content and succulent texture. While it’s predominantly associated with Japanese cooking, its adaptability has made it a favorite among chefs worldwide for adding a gentle mustard tang to fusion cuisines.
• Mizuna is rich in vitamins A, C, and K, along with minerals like calcium and iron. Because it’s part of the mustard family, it contains glucosinolates—compounds studied for their potential antioxidant properties. However, it’s prized primarily for its crisp texture and refreshing, slightly peppery taste.
• This green is often used in “mesclun mix” or “salad mix” seed packets because its finely cut leaves add visual appeal and a mild spiciness to salads. Farmers appreciate its relatively quick maturity, which allows multiple cut-and-come-again harvests in a single growing season.
• Mizuna remains notably cold-tolerant compared to many leafy greens. In regions with mild winters or protected structures like cold frames, it can be grown almost year-round, making it a go-to choice for fresh, off-season greens in local markets or home gardens wanting extended harvests.

Basic Growing Information

Mizuna is a cool-season crop that thrives in temperatures ranging from about 10–25°C (50–77°F), with the optimal temperature being around 15–20°C (59–68°F).

Mizuna is remarkably tolerant of both heat and cold, enabling you to extend your harvest season from late spring/early summer through the autumn and even into early winter in most years. it is tolerant of light frosts and very slow to bolt, making it an ideal choice for early spring or autumn planting, to avoid bolting (going to seed) in summer heat. It is sensitive to high temperatures above 25°C (77°F), , which can prompt flowering and reduce leaf quality, and typically bolts when summer temperatures consistently reach around 32°C (90°F) or higher, but you can start growing it again in early fall as the weather cools.

It prefers slightly moist, well-drained, nutrient-rich soil with full sunlight but can also grow in partial shade. Water regularly to keep the soil moist but avoid waterlogging to prevent root rot or mildew. Mizuna can tolerate slightly alkaline soil.

In cooler climates or regions with short growing seasons, starting seeds indoors 4–6 weeks before the last frost date and transplanting them outdoors once temperatures stabilize can yield earlier harvests. This is rarely done though, as mizuna seed is most commonly directly planted.

The optimal temperature range for seed germination is about 13°C to 24°C (55°F to 75°F), although the seeds can begin to sprout at temperatures as low as approximately 4°C (0°F). seedlings emerge after around 4 to 7 days. The seeds have a long storage life, and can be saved for 4 years.

• Sun Requirements: Full sun to part shade (with full sun especially in cooler months)
• Water Requirements: Medium (consistent moisture but avoid soggy conditions)
• Soil Types and Properties: Prefers fertile, well-draining loamy soil enriched with organic matter
• Soil pH: 6.0–7.5
• Pot Size for Container Growing: 20–25 cm (8–10 in) diameter for multiple plants; ensure adequate depth (15–20 cm / 6–8 in)

Planting

• Best Time to Plant:
  • Climates with freezing winters: Early spring for a spring crop; late summer for an autumn crop
  • Climates with milder winters: Early spring or autumn, leveraging cooler conditions year-round

Note: Check gardening calendars for the best planting times in your location

• Spacing: 15–20 cm (6–8 in) between plants, 25–30 cm (10–12 in) between rows
• Seed Sowing Method: Sow seeds directly into the ground or in seed trays for transplants
• Seed Sowing Depth: 0.5–1 cm (0.25–0.5 in) deep
• Time to Harvest: Approximately 4–6 weeks from seed planting to baby greens; 6–8 weeks for mature leaves
• Mature Height/Spread: 20–35 cm (8–14 in) tall, 15–30 cm (6–12 in) wide
• Grown From: Seeds

Care and Maintenance

• Watering Tips: Water plants consistently to keep soil slightly moist, supplemental watering only needed if rainfall is insufficient. Water at the base of plants to reduce splash and potential leaf diseases. Mulching around young seedlings helps maintain soil moisture, keeping leaves succulent and preventing dryness that can encourage early bolting.
• Fertilization: Incorporate (dig in) compost or a balanced organic fertilizer before planting. Mizuna grows quickly, so lightly side-dressing with fertilizer for a bit of a boost mid-season can maintain lush leaf growth—especially if you plan on multiple harvests. Avoid excessive fertilizing, as overly rich nitrogen fertilizing can lead to rapid soft growth more susceptible to pests and disease.
• Pruning: Mizuna doesn’t require formal pruning, but continuous harvesting of outer leaves or cutting baby greens encourages fresh regrowth. If flowers appear, pinch them off to prolong leaf production. In warm conditions, the plant may rapidly bolt, after which leaves can turn bitter or tough—harvest promptly if bolting is imminent.
• Support: Mizuna’s upright rosettes generally stand without support, but in dense plantings or when grown in breezy locations, leaves may sprawl. Gentle staking or row covers for pest protection suffice. Ensure ample spacing so leaves don’t crowd, improving airflow and minimizing disease risk.

Growing Difficulty

• Easy to Grow

Growing Tips

• Succession sow seeds every 2–3 weeks to enjoy a continuous supply of tender greens. Because mizuna matures rapidly, these staggered plantings ensure fresh leaves are always available rather than all maturing at once. Keep an eye on daytime highs—plantings in sweltering heat typically bolt sooner.
• If pest insect pressure (like flea beetles) is high, consider using floating row covers or fine netting to protect young seedlings. Mizuna is part of the mustard family, which can be a magnet for pests seeking Brassicas. Good sanitation (removing plant debris) and rotating crops helps reduce persistent pest populations.

Companion Plants

• Good companion plants include: Onions, garlic, dill, and marigolds (which may deter pests); lettuce or spinach also fit well in cool-season beds
• Avoid planting near: Other Brassicas (like cabbage, kale) in consecutive seasons if you want to minimize shared diseases; also keep distance from invasive mustards if cross-pollination is a concern, as plants from the Brassica family easily cross pollinate!

Common Pests and Diseases

• Pests: Mizuna generally suffers less insect damage than other brassica crops.
  • Flea Beetles: Use row covers; maintain weed-free beds
  • Aphids: Spray off with water or apply insecticidal soap; encourage beneficial insects
  • Cabbage Loopers: Handpick caterpillars; use BT (Bacillus thuringiensis) if infestations are heavy

• Diseases:
  • Downy Mildew: Improve airflow; avoid overhead watering
  • Clubroot: Rotate crops; maintain soil pH near neutral
  • Leaf Spot: Remove infected leaves; practice good sanitation

Harvesting

Harvest Time:

• Mizuna may be harvested at any stage, from baby greens to full mature leaves.
• For baby greens, begin picking leaves once they reach 10–15 cm (4–6 in) tall—typically 4–6 weeks after planting.
• For fuller heads or older leaves, wait 6–8 weeks. In moderate climates, a single sowing can yield multiple cuts. Harvest leaves before they turn tough or bitter, particularly if weather warms rapidly.

Harvesting Methods:

1. Harvesting the Entire Plant at Once

• Method: Use clean scissors or a sharp knife to cut the entire rosette (entire bundle of leaves) off near the ground in one go, right where it meets the stem (just above the crown or growing point). This generally means cutting very close to the soil line—often around 1–2 cm (1/2-1 inch) above ground.
• Purpose: This is ideal if you want a single, large harvest for immediate use or if you’re nearing the end of the growing season. Practically, this can be used as a single large harvest (a “one-and-done” approach).
• Regrowth Note: Because most leaf tissue and part of the crown may be removed, regrowth can be limited or nonexistent. If you want multiple harvests, leave enough stem and avoid damaging the central growing point.
• Advantages:
  • Collects a large quantity of greens quickly.
  • Minimizes effort—ideal for a one-time or infrequent harvest.
• Disadvantages:
  • If cut too close to the crown, regrowth can be slowed or prevented.
  • Requires re-planting if you want subsequent harvests—unless you leave enough stem material for regrowth.

2. Cut-and-Come-Again (Partial Harvest)

• Method: Cut the greens about 5 cm (2 inches) above the ground, leaving enough stem and preserving the plant’s crown and some leaf stubs, for the plant to continue photosynthesis and recover quickly. This method allows for regrowth, and specifically aims at getting multiple harvests from the same plant, for an all-season-long harvest.
• Frequency: With good growing conditions, mizuna can regrow in as little as two to three weeks. You can repeat this harvest cycle multiple times throughout the season.
• Purpose: Designed for repeated harvests. After a few weeks of regrowth, you can cut again at the same height.
• Regrowth Note: By leaving more of the plant intact—especially the crown—you enable continued leaf production throughout the season. After a second or third harvest, consider re-sowing seeds or planting new seedlings for optimal leaf quality throughout the season.
• Advantages:
  • Encourages continuous production—ideal for those who want a steady supply of fresh greens.
  • Leaves enough of the plant intact (both leaves and crown) for faster recovery and regrowth.
• Disadvantages:
  • Each harvest yields fewer leaves than a full cut.
  • Requires attention to growing conditions (e.g., adequate water and nutrients) to keep the plant producing vigorously.

3. Individual Leaf Harvest (Leaf-by-Leaf)

• Method: Snip or pinch off outer leaves only once they reach a usable size, leaving the inner leaves (and central crown) untouched, to continue growing..
• Purpose: Ideal if you just need a small amount of greens at a time or want continuous, gentle harvesting.
• Regrowth Note: This approach keeps the plant actively growing and can extend the harvest window. The inner leaves continue to mature, providing a near-continuous supply.

Harvesting Tips:

• For best quality, flavor and texture, harvest in the cool morning, after the dew has dried but before the heat of the day softens the greens.

Storage:

• Store unwashed leaves loosely wrapped in plastic in the refrigerator for up to a week, washing just before use.

Propagation

Produce New Plants From: Seeds

Culinary Uses

Mizuna’s mildly spicy, crisp leaves lend themselves to numerous culinary applications. Often served raw, these feathery greens add a delicate mustard note to salads. Because mizuna is less pungent than some other Asian greens, it’s popular in mesclun mixes where it brings subtle pepperiness without overwhelming other flavors. Some cooks pair mizuna with sweeter dressings or fruits to balance its mild bite; think of a salad with sliced pears, toasted nuts, and a tangy vinaigrette.

When briefly wilted, mizuna maintains a tender texture. Add it at the last moment to soups or stir-fries for a bright, leafy finish. In Japanese cuisine, mizuna is sometimes used in nabemono (hot-pot dishes) or lightly pickled with other vegetables. A quick sauté with garlic, sesame oil, or soy sauce transforms it into a simple, nutrient-rich side dish. Because it cooks faster than heartier greens like kale or collards, watch carefully to avoid overcooking and preserving its vibrant color.

For a fusion spin, chop mizuna into omelets or quiches for a mild mustard accent, or toss it into pasta dishes with sautéed onions, mushrooms, and olive oil. It can also be blended into pestos or sauces in small amounts to add complexity alongside basil or parsley. Despite its slender appearance, mizuna is adaptable—equally at home in warm or cold recipes. Whether used raw in salads or briefly cooked for a subdued peppery tone, mizuna offers a flavorful, flexible addition to the kitchen repertoire.

In conclusion, mizuna is a fast-growing, cold-hardy green that fits effortlessly into home gardens. By planting in mild conditions, ensuring consistent moisture, and harvesting regularly, you can enjoy multiple flushes of its finely serrated leaves. Given its broad culinary range—from fresh salads to quick stir-fries—mizuna stands out as a reliable, adaptable leafy green for both novice and experienced gardeners.

References

• Mizuna: an Asian Green. Pennsylvania State University. PennState Extension. https://extension.psu.edu/mizuna-an-asian-green
• Explore Cornell – Home Gardening – Vegetable Growing Guides – Growing Guide. Cornell University.. http://www.gardening.cornell.edu/homegardening/scene46c5.html
• Asian Greens | UC Agriculture and Natural Resources. University of California. UC Agriculture and Natural Resources. https://ucanr.edu/site/uc-master-gardener-program-sonoma-county/asian-greens
• Amoore. (2021, June 25). UT Gardens’ October 2018 Plant of the Month: Mizuna. UT Gardens – the State Botanical Garden of Tennessee. https://utgardens.tennessee.edu/ut-gardens-october-2018-plant-of-the-month-mizuna/