Growing and Saving the Seed of Mizuna

Latin name Brassica rapa var. japonica (alternatively Brassica rapa var. nipposinica) A cool-season, leafy Asian green with a lovely mild flavor. Mizuna has thin stalks and deeply serrated foliage. It resembles mustard greens, but it is typically much less pungent.



Mizuna is a Kyo Yasai, or traditional vegetable of Kyoto. The thin and flavorful greens have been enjoyed in Japan since antiquity, and mizuna was a standard green on imperial banquet tables. The traditional Kyo Yasai designation is limited to vegetables grown before the Meiji period of the 1800s; mizuna is one of those treasured Japanese delicacies.


  • Culinary
  • Edible ornamental
  • Container growing




  • Direct sow outdoors from early spring to late summer; you can sucession sow every 2-4 weeks. 1/4 inch deep (1/2 inch deep in summer to keep seeds cooler).
  • Ideal germination temperature is 75 but seeds will sprout between 45-80F.
  • Sow seeds 1 inch apart in rows 18 inches apart.
  • Thin to 6 inches apart.
  • Seeds germinate in 4-7 days.


  • Full sun to part shade.
  • Provide loose, well-drained soil. Incorporating well-rotted compost into the planting site will help the greens to thrive but is not essential.
  • Regular water requirements.
  • Full grown should be ready to harvest in 40 days; baby greens can be harvested sooner.


  • Less susceptible to brassica pests and diseases than its other brassica relatives. However, mizuna can be affected by these pests; use floating row cover from time of planting to prevent insect damage.
  • To prevent disease and pest damage, do not plant brassicas in the same place repeatedly.


  • This annual member of the brassica family is insect pollinated. It will not cross with all other members of the large brassica family; it can only cross with other members of the rapa species, which is much smaller.
  • It is best to isolate flowering plants from other members of the rapa species by 800 feet to 1/2 mile or use caging techniques. The most practical choice is to just grow one Brassica rapa for seed saving per season!
  • Allow plants to flower, the green pods to form and then brown and dry, then wait for a dry day and pull up the plants.
  • Dry the pods further in a warm, dry, well-ventilated location. Many will lay the plants on tarps and beat the pods open to free the seeds.
  • Separate seeds from chaff and place seeds in an airtight container. Store in a cool, dark, dry location.