While visiting YouTube which is something I do frequently, I came across videos of people regrowing vegetables from a part that was left over. I've tried this with celery, green onions, basil and some others. These were all curiosity experiments and no expectations of a full-fledged plant.
After cutting across the base of the plant,
|copied from http://blog.spacegirlorganics.com/regrowing-bok-choy/|
|Top view after two weeks|
|Side view after two weeks|
|You can see the roots attached to the soil|
After shaking off the dirt this is what was left.
|The plant really hasn't grown that much.|
I'll eat the leaves off of this and keep sprouting it in water until its completely spent.