This traditional saying sets a benchmark for corn growth in the American Midwest. If the stalks reached a farmer's knee by early July, the crop was developing fast enough to yield a good harvest before the autumn frost. With newer, taller hybrids and earlier planting dates, healthy corn usually far exceeds this height by early summer.
Heard on the job
The corn is already chest-high, so we blew right past knee-high by the Fourth of July this year.
Insider tip
While older farmers still repeat the saying, newer genetics mean corn should be at least waist-high by early July to hit peak yield targets.