When to Plant Corn
Vernacular measurement is only as precise as it needs to be for the purposes at hand. It is symbolized in such expressions as a "pinch of salt," "a stone's throw; "a book of hay," "within shouting distance." And for many purposes, vernacular rules may prove more accurate than apparently more exact systems. A case in point is the advice given by Squanto to white settlers in New England about when to plant a crop new to them, maize. He reportedly told them to "plant corn when the oak leaves were the size of a squirrel's ear." An eighteenth-century farmer's almanac, by contrast, would typically advise planting, say, "after the first full moon in May," or else would specify a particular date. One imagines that the almanac publisher would have feared, above all, a killing frost, and would have erred on the side of caution. Still, the almanac advice is, in its way, rigid: What about farms near the coast as opposed to those inland? What about fields on the north side of a hill that got less sun, or farms at higher elevations? The almanac's one-size-fits-all prescription travels rather badly. Squanto's formula, on the other hand, travels well. Wherever there are squirrels and oak trees and they are observed locally, it works. The vernacular observation, it turns out, is closely correlated with ground temperature, which governs oak leafing. It is based on a close observation of the sequence of spring events that are always sequential but may be early or delayed, drawn out or rushed, whereas the almanac relies on a universal calendrical and lunar system.
