Bok Choy is called many things but basically it’s Chinese cabbage, and it grows great here. Bok Choy is a cool-season vegetable: a term that throws many people off. Here’s an example–I once had a call at the Santa Clara Hotline from a man wondering why his broccoli wasn’t growing. After asking a series of questions, I learned he had planted the broccoli in complete shade. I can sort of see the reasoning behind that; cool season, grows in winter, under a tree is kind of cool, cool-season vegetables should grow there then, right? Wrong. Cool-season vegetables mean that the vegetable doesn’t need as many hours of sunlight, and that cold overnight temperatures won’t negatively affect the plant.
Here’s another way of distinguishing between warm and cool-season vegetables as explained by Rosalind Creasy in her Edible Landscaping book p. 114: Warm season vegetables grow best in temperatures between 70-100 degrees F. They cannot tolerate frost. The seeds and fruits of warm-season vegetables are the edible parts (e.g., beans and corn are seeds, tomatoes and zucchini are fruits). Cool-season vegetables are the roots, bulbs, tubers, leaves, flower buds (e.g., radishes and carrots are roots, broccoli is the flower buds of the plant, spinach is the leaf, etc.), and they grow best when the temperatures are between 50-70 degrees F. Most cool-season vegetables tolerate frost.
Even though Bok Choy is a cool-season vegetable, now is the time plant the seeds. You want the plants to mature in the fall–if you wait too long, the plants may not head well because the weather will be too cold, too fast. As with other cole crops (cabbage, broccoli, cauliflower, and Brussels sprouts) temperatures can be a significant factor in how well the plant will flourish.
We use Bok Choy almost exclusively in stir-fries and soups. Because of the stalk, Bok Choy is kind of like two vegetables in one. It has the crunch of celery and the leafy greens of chard. It shrinks down enough that my kid isn’t really aware of eating a leafy green. I’m not quite sure when kids really start enjoying the texture of salads with lettuce greens, but it hasn’t happened yet in our home. I have to get the leafy greens in her diet in more creative (hidden) ways.