Mizuna (Japanese greens) is a versatile, leafy crop with a mild mustard flavour similar to rocket, but slightly more bitter. Also known as kyona or potherb mustard, this Japanese brassica is packed with vitamin A, C and K as well as calcium, iron and folate. It also contains glucosinolates, which may reduce the risk of cancer.
As well as eating the fresh salad leaves, the young, flowering stems of mizuna can be cooked like broccoli or the stems and leaves can be pickled.
How to grow mizuna
Mizuna can be grown all year round. Sow seeds under cover in autumn and winter and outdoors in spring and summer. It can be grown as a cut-and-come-again salad, or you can also allow the leaves to mature.
Where to grow mizuna
Mizuna can be grown in the ground or in pots. Choose a spot with some shade and keep watered. Avoid sunny, dry conditions which may cause it to bolt, resulting in unpleasantly bitter leaves.
The amount of space you give mizuna to grow in depends when you want to harvest, for regular crops of smaller leaves space 15cm apart, for larger leaves allow 20cm and for a fully grown mature plant it will need 40cm of space.
How to care for mizuna
Mizuna is very tolerant of cool and damp conditions, most varieties do best in shade in summer. It needs a moist soil, as dry conditions could cause the plant to bolt, which means that it flowers early which can result in unpleasantly bitter tasting leaves.
How to propagate mizuna
Mizuna is best propagated from seed, sow outdoors from March to August or sow indoors earlier in the year and harden-off before moving outside. Sow regularly for a continuous supply of fresh leaves.
How to harvest mizuna
You can harvest and use mizuna in a variety of ways. Pick the young leaves as soon as they are large enough and add them to salads. Alternatively, leave them to mature and gently steam the leaves or add to stir-fries. You can also allow the plant to fully grow and harvest the full rosette after six to eight weeks.
For the best flavour and nutrients, the leaves and stems should be eaten immediately. However they can be stored in the fridge for up to five days. Don’t wash prior to storage to avoid the leaves rotting.
Pests and diseases
Slime trail and damage to young seedlings is probably a result of slug and snail damage.
Leaves covered in small holes and browning of leaves could be as a result of the flea beetle, to avoid this grow seedlings underneath horticultural fleece and keep the soil moist. The holes don’t affect the leaves beyond their appearance, and they are still edible.