Nasturtiums wander about near the fence. I believe you can eat the flowers though I've never done it.
Genesis 2:15-17 (New International Version)
The LORD God took the man and put him in the Garden of Eden to work it and take care of it. And the LORD God commanded the man, "You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die."