Plant in full sun in a somewhat cool spot that has rich, loose soil with good drainage to prevent crown rot. Add organic matter to help retain moisture. For poor-draining soil, plant in raised bed that is not higher than 6 inches to keep soil from becoming too warm. Feed young plants with composted manure or balanced fertilizer. Grow under row cover to keep out flea beetles or spray regularly with Bt, Bacillus thuringiensis, to prevent worm damage.
Some gardeners prevent flea beetles by alternating rows of pak choi with garlic and green onions.
First, harvest outer tender leaves. As weather heats up, harvest tender inner leaves. Keeps several weeks in refrigerator. A flower stalk means leaves are getting tough. Cook lightly or stir-fry leaves.