Wow, strange! Is that only in the spring, or do late summer/early fall crops also bolt? At least you can have microgreens and baby leaves before they go to seed!
I thought it took warmth or medium-heavy frost to make Bok Choy bolt.
Tatsoi is more cold-tolerant, but grows slower and lacks the sweet crunchy stems.
I have a wide variety of Bok Choy varieties, with different bolting tendencies if you would like to test a few. Maybe shade would help in early summer, or keeping soil more moist.
White stem:
Joi Choi - F1 Hybrid - fall or winter bolt-resistant
Kitazawa #056 - To avoid bolting plant later in cool areas.
pick when young:
'Round Leaf San Tong' - marketed as "Taiwan Bok Choy" - 35 days
Extra Dwarf OP Pak Choy pick when 2" tall
Green Stem:
Shanghai Pak Choi - 'San Fan' Hybrid - Early maturing, heat tolerant
Baby 'Mei Qing Choi' - Hybrid 35-40 days - tolerates heat & cold - good bolt resistance
Baby Bok Choy 'Ching Chang #5001' - tolerates high heat
Bok Choy 'Dong Zhi' - F1 Hybrid green stem - Best suited to cool areas
