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When you purchase bok choy from the grocery store or farmer's market, it likely comes in a plastic bag. Keep it in the bag when you store it to keep it as fresh as possible. Ideally, the plastic bag that you store the bok choy in should be perforated. If the bag isn't, you may want to poke a few holes around the bag with a knife. To ensure that the bok choy stays fresh as long as possible, you should store it in your refrigerator. In particular, the crisper drawer is an ideal spot to keep the vegetable. You can freeze bok choy, but you must blanch it first, drain it well, and place it in freezer bags beforehand. Frozen bok choy will keep for 10 to 12 months. While you may think it's a good idea to clean the bok choy before you store, you should actually leave it unwashed until you're ready to use it. If the bok choy isn't completely dry when you store it in the refrigerator, the leaves can become slimy and wilted. If you don't wash the bok choy before you store it, it can last for 3 days in the refrigerator.
Secure the bok choy in a plastic bag. Keep the bok choy in the refrigerator. Leave the bok choy unwashed until you're ready to use.