Vegetable · Brassicaceae
Mizuna
Brassica rapa var. nipposinica
Sow it in cool weather, keep it watered, and cut it often, and mizuna keeps feeding you for weeks.
Full sun
Every 2–4 days
39–75°F · 4–24°C
20–45 days
Overview
Mizuna is a Japanese mustard green with feathery, deeply cut leaves and a mild peppery taste that lands somewhere between arugula and a young mustard. It belongs to the cabbage family and grows fast, going from seed to a first cutting in about three weeks. People eat it raw in salads and toss it into stir-fries and soups near the end of cooking.
What makes it a favorite is how forgiving it is. It is a cool-season crop that handles light frost, comes back after each cutting, and asks for little beyond steady moisture. Heat is its one weakness, since hot, long days push it to flower and turn the leaves bitter.
Grow it as a cut-and-come-again green and a single sowing keeps producing for weeks. Sow in early spring and again in late summer, harvest the outer leaves as you need them, and the plant pushes out fresh growth from the center.
Care
The short version: give mizuna full sun to part shade in cool weather, keep the soil evenly moist, plant in rich, well-drained ground, and cut the leaves often to keep new ones coming.
Light
Mizuna does best in full sun, around 6 or more hours a day, but it takes partial shade without complaint. In warm spells that bit of afternoon shade is an asset, since it slows the bolting that heat brings on.
Water
Keep the soil evenly moist and the leaves come in fast and tender. It will get by on lean soil and less water, but flavor and quality fall off, so plan to water every 2 to 4 days. Steady moisture is what keeps the greens mild instead of sharp.
Soil
Plant in well-drained ground rich in organic matter, with plenty of compost worked in. A pH between 6.0 and 7.0 suits it well, which covers most garden soils without much fuss.
Temperature
Mizuna grows in cool weather, happiest from about 39°F to 75°F (4°C to 24°C). It shrugs off light frost at the low end, while heat near the top pushes it to flower and sour.
Humidity
Ordinary humidity, somewhere around 40% to 70%, is all it needs, so there is no number to chase outdoors. Good airflow matters more than the figure, since crowded, damp leaves invite pests and rot.
Feeding
Work aged compost or a balanced, nitrogen-rich feed into the bed before sowing, then feed monthly through the growing season. The nitrogen drives the leafy growth you are after, but go steady, since soft, overfed growth draws aphids.
Pruning
Harvesting is the pruning here. Cut the leaves about 2 inches (5 cm) above the crown or pick the outer leaves one at a time, and the plant regrows for cutting after cutting. That cut-and-come-again habit is what keeps a single sowing going for weeks.
Size & spacing
Plants stay compact, reaching 8 to 18 inches (20 to 45 cm) tall and about as wide. Give each one room to spread to that 10 to 18 inch (25 to 45 cm) spread so air can move and the leaves stay clean.
When to plant
Mizuna is built for the cool ends of the year, not the middle of summer. Sow it in early spring as soon as the soil can be worked, then sow again in late summer for a fall crop. It tolerates light frost, so the season stretches well past the first cold nights.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 4-6 weeks before last spring frost, or direct sow
- Plant: early spring and again in late summer; cool-season and frost-tolerant
- Harvest: baby leaves about 21 days, full leaves about 40 days; cut-and-come-again
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Most mizuna trouble comes down to a few brassica pests and the heat that makes it bolt. Catch the early signs on the leaves and you can usually head off the worst of it. Match what you see below and act while it still helps.
Seedlings wilting and toppling over from the roots up
When young plants wilt for no clear reason, pull one and check the roots for white grubs and tunneling, the calling card of the cabbage maggot. Dig out and destroy the plants that are already hit, and use row covers to keep the egg-laying flies off the bed. Rotate your brassicas and skip beds freshly worked with manure, which draws the flies in.
Fix:
- Remove and destroy affected plants
- Use row covers to exclude egg-laying flies
Plants shooting up flower stalks as the leaves turn bitter
Heat and lengthening days push mizuna to bolt, sending up a central flower stalk while the leaves sour. Once temperatures near 90°F (32°C) the clock is against you, so cut the crop while it still tastes good. Sow a fresh batch in late summer for a fall harvest, and give the plants afternoon shade through any warm spell.
Fix:
- Harvest promptly before flavor declines
- Resow in late summer for a fall crop
Tiny shot-holes peppering the young leaves
Those pinholes are the work of flea beetles, little black insects that jump when you disturb them and hit seedlings hardest. Lay a floating row cover over the bed right at sowing so the beetles never reach the plants. Moving new plantings away from brassica beds that had trouble last year helps too.
Fix:
- Cover plantings with floating row cover at sowing
- Relocate plantings away from previously infested brassica beds
Sticky clusters of soft insects on the new growth
Green or gray colonies on the leaf undersides and tender tips are aphids, and the sticky film they leave behind gives them away. Knock them off with a hard jet of water, and follow up with insecticidal soap if they keep coming back. Easing off on nitrogen makes the soft new growth they crave less inviting.
Fix:
- Rinse plants with a strong jet of water
- Apply insecticidal soap to affected foliage
Toxicity
Mizuna is a food crop and safe all around, grown for the table and harmless to cats, dogs, and the other animals on the farm. There is no toxic part to keep away from anyone. The only mild note is the goitrogens shared across the cabbage family, which matter only when livestock graze brassicas heavily for a long stretch.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Safe around cats. A curious nibble of the peppery leaves causes no harm, though a big helping of any greens can loosen the stomach.
Dogs None
No toxic compounds here, so dogs can be trusted near the plants. Plain leaves are fine in small amounts as the odd treat.
Horses Safe
Horses can graze mizuna without trouble. It belongs to the mustard family, so keep it as a minor part of the diet rather than a staple.
Rabbits Safe
Rabbits enjoy the tender leaves, and they make a healthy green. Introduce them gradually, the way you would any new fresh food.
Livestock Mild
Cattle, goats, and sheep can eat mizuna safely. Only heavy, sustained grazing on brassica forage risks the goitrogenic effects common to the family, so mix it with other pasture.
Birds Safe
Backyard hens and other birds can peck the leaves with no concern. The greens add useful variety to their feed.
People Safe
Mizuna is grown to be eaten, raw in salads or wilted into a dish. There is nothing to avoid for healthy people.
Like other brassicas it contains glucosinolate goitrogens, which are mainly a concern for heavily grazed livestock rather than household pets.
Varieties
Mizuna comes in only a couple of common forms, and the choice mostly comes down to color. Both grow and taste much the same.
Mizuna (green)
The classic form carries deeply serrated, feathery green leaves on thin white stems and tastes mildly peppery.
Red Kingdom / purple mizuna
A burgundy-tinged version with purple stems that gardeners grow to add color contrast to salad mixes.
How to propagate
Mizuna is grown from seed and nothing else, and it is one of the simplest greens to start. Sow it straight into the ground and you are weeks from your first cutting.
SeedEasy
Direct sow in early spring and again in late summer; succession sow for continuous harvest · Germinates in about 4-8 days at 55-75°F; baby leaves ready in roughly 21 days
Mizuna is almost always started from seed sown right where it will grow. Sow it 1/4 to 1/2 inch deep in cool, moist soil and it sprouts in about 4 to 8 days, with baby leaves ready to cut in roughly 21 days. Sow a fresh row every couple of weeks and grow it cut-and-come-again for a steady supply.
Myths
Mizuna is a hot, sharp mustard that has to be cooked before you eat it.
The flavor is mild, just a gentle peppery edge rather than a bite. It is at its best eaten raw in salads, though it also braises well, so cooking is a choice and never a requirement.
Mizuna is a warm-season green that needs summer heat to thrive.
It is a cool-season crop that shrugs off light frost and is slow to bolt. Spring and fall are its seasons, and summer heat is what pushes it to flower and turn bitter.