Dear Word Detective: I am looking for a source for the term “green thumb.” Even though it seems in a way obvious that one’s thumb might be called “green” just because plants are green, why the thumb? Why not a “green finger” or a “green hand”? My dad is really the one who got me interested in this, and his best explanation found so far is that good gardeners eliminate unwanted shoots from a stem by pinching them between the thumbnail and the index finger, leading to a green thumb there near the thumbnail. This seems a little dubious, and I can’t remember if he found it written up somewhere or if someone supplied this in person; either one could be a folk etymology, I guess. Anyway, hope you can shed some light on the subject. — Melissa Mitchell.
Oh, no, it’s spring again, isn’t it? Spring is my least favorite time of the year, mostly because I’m expected to go outside and muck around with plants and things, which I hate. This year, I’m told, we’re going to be raising absolutely all our own food in our very own garden, which I rather doubt unless somebody invented pizza seeds and doughnut plants over the winter.
I, too, had always assumed that “to have a green thumb,” meaning to have a natural talent for growing things, invoked “green” because most plants are green, and that does seem to be the explanation for the color. But the more I looked into the phrase, the more interesting it became.
The answer to “Why the thumb?” is simple on one level. It isn’t just a “green thumb.” In Britain, they speak of a gifted gardener having “green fingers,” although “green thumb” is also commonly heard. “Green fingers” first appeared in the 1930s, followed about ten years later by “green thumb.” As to how one’s thumb or fingers get green, there seem to be several theories, the most predictably implausible of which involves, as usual, British royalty. In this tale, King Edward I developed a love of green peas and kept a dozen servants shelling them. The most proficient sheller, judged by the green stains on his fingers, was richly rewarded. You’ll notice that this story is not only silly but doesn’t really have anything to do with gardening. More plausible is the observation that the green algae that grows on pots often rubs off on the gardener’s fingers.
But the saying, whether “thumb” or “fingers,” does seem to have a bit more of a story behind it. In the period immediately preceding and during World War II, one of the most popular programs on BBC radio in Britain was called “In Your Garden,” the host of which was a Mr. C.H. Middleton. The eminent etymologist Eric Partridge suggested that this program might have popularized both phrases, and that “green thumb” was actually a reference to the very old English proverb “An honest miller has a golden thumb.” Millers, merchants who grind corn for farmers, used to judge the quality of their product, corn flour, by rubbing a bit between the palm and thumb. But millers were often suspected of cheating their customers, and “golden thumb” was often used sarcastically, including by Chaucer, to mean a talent for duplicity. In any case, the proverb was sufficiently well known in Britain in the mid-20th century to make the “golden thumb” and “green thumb” connection plausible, and would explain why the thumb in particular is found in the most common form of the phrase.