Mizuna is a mild flavored Japanese mustard that is quite commonly grown for commercial salad mixes. It has lobed green leaves with a pleasant bitter taste. Mizuna is a close relative of turnips but has a flavor all its own. Ridiculously easy to grow, it grows quickly and even re-grows well when harvested as cut-and-come-again. Although often eaten fresh, the leaves are just crisp enough to hold up to light cooking, like steaming or stir-frying. Many people also like to pickle the leaves and use them as a condiment.
- Leaves: The plant grows in a rosette with fringed or deeply serrated leaves. There are green and purple-leafed varieties.
- Flowers: The flowers are the typical yellow, 4-petal cross of vegetables in the cruciferous family.
Brassica rapa nipposinica or japonica
Mizuna kyona, shui cai
Mizuna is a biennial, although spring plants may go to seed their first year if left in the ground until fall. I have seen it labeled as hardy to USDA Hardiness Zones 4 - 9, but even if it survives winter, it will blot to seed quickly, in the spring. You can over-winter it in a cold frame or hoop house, but you should plan on eating it before it starts to flower.
Although it will grow in full sun, Mizuna actually prefers partial shade. It only needs about 3 - 5 hours of sun each day.
Size will depend on both the variety you are growing and whether you choose to harvest mature heads, individual leaves or baby heads. A full-sized head will reach a size of about 5 - 7 inches (h) x 10 - 15 inches (w). These are loose heads. Mizuna will not form a tight ball.
Days to Harvest
You can start harvesting small leaves in about 20 days. Full heads should begin forming in 40 days.
Very often you will find seed simply labeled as Mizuna, although the seeds themselves will vary from company to company. The plants are fine, but if you find one you particularly like, you may not be guaranteed of getting the same thing next year. Named varieties are starting to be more commonly sold.
- 'Komatsuma' - Slender leaves. Very drought and frost tolerant.
- 'Kyona' - Frilly leaves on pencil-thin stalks. Great fresh.
- 'Kyoto' - Deeply serrated leaves with a pleasant bite.
- 'Red Komatsuna' - Not as robust as the green variety, but very flavorful.
- 'Vitamin Green' - Smooth, dark green leaves. Slow to bolt.
Uses of Mizuna
Mizuna is often used as a salad ingredient, where it adds a distinct flavor. You can also use the fresh leaves on sandwiches. Another popular and easy use is to add it to stir-fries. The more tender the leaves, the less cooking it requires.
These greens also make a nice side dish on their own. The blend well is Asian spices as well as with garlic and olive oil and even bacon. I've seen them lightly grilled, with figs.
Mizuna Ichiyazuke ("overnight soaking" pickles) are made with just mizuna greens, salt and dried red chili (Togarashi)
Mizuna Growing Tips
Soil: You'll need well-draining soil with a lot of rich, organic matter mixed in. Since Mizuna is a leafy crop, it will need plenty of nitrogen. It will grow in a soil pH from 6.0 - 7.5, something in the 6.5 - 7.0 range is best.
Planting: You can direct sow or start seed indoors about 4 - 5 weeks before your last frost date. Begin sowing outdoors about 2 weeks before your last frost date and transplant indoor-grown seedlings when they are at least 4 weeks old. Seeds are quick to germinate, usually within 4 - 8 days.
Plant seed 1/4 inch deep. You can either broadcast the seed or space it 1 inch apart. Thin and eat the plants when they are a couple of inches tall. If you are growing full-sized plants, thin to at least a 6-inch spacing.
Maintenance and Care: Since Mizuna is a fast maturing plant, the only real maintenance is keeping it watered. You can succession plant every 2 weeks, for a longer harvest period. Mizuna does not grow well in hot temperatures, but resume planting in late summer and continue through fall.
Plants in the brassica family do not cross-pollinate with plants outside their species. Seed can be saved for 4 years.
Pests & Problems
Mizuna is not prone to the usual brassica diseases. Unfortunately, it is attractive to some pests. Flea beetles do the most damage. Row covers will help to minimize it. Slugs, whiteflies, and aphids can also harm the leaves.