Bopak Pak Choi
Pac Choi is a cool-weather plant which will bolt and go to seed quickly in warm weather and long days; grow pak choi in Spring or Autumn in temperatures ranging from 45° to 75°F. Sow seed 4 to 6 weeks before the average date of the last frost in spring.
Plant seeds ¼-½" deep. Transplant or thin small plants to 15-18" apart in rows 32-36" apart. Transplants can be started in April for May planting. Transplant after 4-6 weeks. Use a starter fertilizer, soaking the root ball thoroughly prior to transplanting. Direct seed in late spring, as seedlings can tolerate a light frost. Can be direct seeded up until mid-late June for a continuous harvest. Soil temperature should be 21-26°C (70-80°F) for optimal germination in 4-7 days.
Prefers full sun, but will tolerate part shade. Prepare a rich, loose soil that holds moisture well and has a pH level of 6.0-6.5. Broccoli is a heavy feeder and will also benefit from applications of calcium and magnesium, particularly during the early stages of growth.
You can harvest the young leaves after 30 days, to add to salads. From 45 days, the plants should have developed a 'heart' and be ready to harvest for stir fries. Pak choi is most succulent and has the best flavour when eaten fresh from the plot, so only harvest what you need, when you need it.
Pests & Diseases:
Cabbage worms and loopers (white and yellow butterflies) can be controlled using BTK, Rotenone or Pyrethrum. Use row covers to block out all insects including root maggots, aphids and Diamondback moths. Maintaining a soil pH of 6.8 and higher will discourage club root. Fungal and bacteria diseases such as head rot and downy mildew can be prevented by allowing good air circulation and avoiding a mid August maturity when the air humidity is higher. Strong healthy plants growing in an organically rich soil will be better able to fight disease.