Bok Choy Seeds,
Shanghai Green

Shanghai Green bok choy is best planted in the cool seasons of spring and fall. For spring planting, direct sow around the last frost date rather than several weeks before it, and set out any indoor-started seedlings after the last frost, so young plants are not left in sustained cold below about 50 F. For a fall crop, sow seeds directly in late summer when temperatures begin to drop. This variety can tolerate light frosts, but extended cold after the seedling stage will push a spring crop to bolt, as will high summer heat. If you're not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Sow seeds 1/4 inch deep in the soil, spacing them about 1-2 inches apart. Once seedlings are established, thin them to about 12 inches apart to give the plants room to grow. Shanghai Green can be grown in rows spaced 18-24 inches apart, or in containers with good drainage. Consistent moisture is key to preventing bolting, so water regularly.

This variety requires full sun to partial shade, especially in the warmer months to prevent overheating. It grows best in temperatures between 60-80 F. Fertilize with a balanced organic fertilizer or compost at planting time. Pests like cabbage worms and aphids can be a problem, so consider using row covers or organic insect controls.

Bok choy is an annual, completing its life cycle in one year. To avoid selecting bolt-prone plants, don't save seeds from prematurely bolted ones. Let plants mature fully, harvest the dried pods, crumble the small round seeds into a jar or bag, then seal and store the seeds in a cool, dark, dry place. Bok choy cross-pollinates with other rapa species but not with different species of Brassica, so it's safe to grow it next to mustard greens (Brassica juncea), for example. To ensure seed purity, isolate your bok choy from other blooming B. rapa by about a half mile or use caging techniques. Allow your healthiest plants to flower for a strong, diverse seed pool.