But the same idea is behind all of them, right?

No, the same idea is not behind all of them. They are three completely different and separate things.

In fact a given product may have all three associated with it in different ways. The "ginger", to use your example, probably has all three associated with it, but each for a completely different reason.

Research the difference between Patents, Trademarks, and Copyrights, and get back to us.