One of the biggest giveaways that bok choy has gone bad is the presence of slime or mold. Think about it like when you leave a carton of milk out on the counter for too long - it's just not a good look.
If you notice any white or greenish patches on your bok choy, it's time to say goodbye. Don't worry, it's not the end of the world - just toss it and grab some fresh bok choy from the store.
