Growing and Saving the Seed of Bok Choy
Latin name Brassica rapa var. chinensis, also known as pak choy and bok choi. A versatile and easy-to-grow member of the cabbage family with succulent, delicious stems and leaves. This Asian green is wonderful in stir fry, salads, and so many more preparations.
Bok choy traces its roots back to 5th century China. It was a popular subject for jade sculpture.Chinese immgrants brough the tasty greens to North America during the early 1900s.
- Direct sow after last frost or start indoors about 4 weeks before last frost date and transplant out after last.
- Sow seeds 1/4-1/2 inch deep.
- Ideal germination temperature is 75 F, though they can germinate between 50-80 F.
- Seeds germinate in 4-7 days.
- Prefers full sun to part shade.
- Average moisture needs.
- Soil should be well drained and ideally amended with well-rotted compost.
- Plant spacing will depend on the variety; large varieties can be spaced or thinned to 12 inches apart, while the small-headed varieties can be spaced 6 inches apart and micro varieties will only need about 2-4 inches. Rows should be 18-32 inches apart.
- Bok choy is fairly heat tolerant, but it should be noted that frost or sustained nightime temperatures under 50 F may cause the young plants to bolt, so resist the temptation to plant them out too early. Cold temperatures typically will not cause mature plants to bolt. Sow again in late summer for fall harvest. When sowing in fall, be sure to mulch plants and provide consistent moisture.
- Weevils can be a pest of bok choy during winter/spring/ fall crops (they go dormant in summer). Use floating row cover at time of planting to prevent weevils if they are a pest of bok choy in your region.
- Bok choy is an annual, meaning it will grow and flower and make seed all in one year. Be sure NOT to save seed from prematurely bolted plants as you will essentially be selecting for bolt-prone plants.
- Allow plants to mature and go to seed, harvest dried pods and crumble the small round seeds into a sealed jar or bag, and store in a cool, dark, dry location.
- Bok choy will cross pollinate with other members of the rapa species, but will not cross with different species, so it is safe to grow a seed crop of bok choy next to a seed crop of mustard greens (Brassica juncea) for example. Insects cross pollinate the flowers, so be sure to isolate your bok choy from other blooming brassica rapa by about a half mile, or use caging techniques.
- Allow several of your best-looking bok choy to go to flower in order to provide a nice wide genetic pool and a stronger saved seed over time.