Bok choy Brassica rapa var. chinensis is a leafy green vegetable of the cabbage family. They are available with green or white stems, rosette shapes (Brassica chinensis var. narinosa), and flowering types (includes Choy Sum). Other names for Pak Choi (Bok Choy) include Chinese celery cabbage, mustard cabbage, Bai cai (white stem), qing cai (green stem), chingensai (green stem), shakushi-na (white stem), and taisin. Because the whole plant is edible, everything from the leaves, shoots, and young flowers are commonly used in Asian cuisines. Generally, these vegetables are considered to be a cool-season crop and can bolt or become bitter when exposed to high temperatures. However, some varieties of bok choy are more heat tolerant than others. Here are a few varieties of bok choy that are known for their heat tolerance.
Heat Tolerant Pak Choi (Bok Choy) Varieties
Joi Choi is a hybrid variety of bok choy that is known for its heat tolerance and uniformity. Its large and vigorous leaves have a slightly sweeter flavor than other bok choy varieties and produce tender, juicy stalks. The stalks are bright white with green leaves. Mature in 40-50 days.
Summer Zest is another hybrid bok choy variety that is heat tolerant but is green throughout the whole plant. It has a compact growth habit and produces large, upright heads. Matures in 40-45 days.
Fun Jen is a Taiwanese variety of bok choy that is known for its heat tolerance and frilly leaves with white petioles. It has a slightly bitter flavor and produces large, upright heads. The tender and crisp leaves make for a perfect addition to stir-fries.
When growing heat-tolerant bok choy varieties, it's crucial to provide them with proper soil and water conditions to ensure healthy growth. They have relatively small root systems making moisture-retentive soil a must! We recommend using the Max Water Retention Mix to amend the soil quickly. Without enough water, the plants will wilt and bolt prematurely. Additionally, using shade cloth or other protective measures can help to keep the plants cool and prevent bolting. Because of their short root systems, Pak Choi is also an excellent option for container gardens. Don’t forget to include these varieties in your fall gardens for a harvest of delicious tender greens.