What’s The Difference Between Mustard Greens And Collard Greens?

What’s The Difference Between Mustard Greens And Collard Greens? So what is the difference between mustard and collard greens? The main difference is that mustard greens are considered an herb while collard greens are part of the cabbage family. Their flavors are also vastly different, and they each contain various levels of vitamins and minerals.