How We Got the Expression “Green Thumb”

All gardeners know that if you have a “green thumb,” you're likely a master at making things grow. Have you ever wondered how that expression came to be? It actually comes from the fact that algae growing on the outside of earthenware pots will stain a person’s thumb (and fingers) if the pots are handled enough. Hence, a person always working with flower pots has a green thumb. Another theory purports that King Edward I of England was so fond of peas that he kept a half a dozen serfs shelling them during the season. The serf who had the greenest thumb won a prize.