What’s the deal with “Knee-high by the Fourth of July”?

The truth behind an old saying

“Knee-high by the Fourth of July” is an old adage used by corn farmers near and far to measure the success of their crops come Independence Day. Last week, farmers across the United States celebrated the Fourth in the same spirit as generations before them. When they looked to their crops, did they see the same knee-high cornstalks as their predecessors?


Years ago, knee-high corn in early July was thought to indicate high yields for the year. However, fast forward to the present day: Knee-high stalks in late June and early July signal trouble to farmers. With significant advances in agricultural technology, genetics and improved Plant Health, today’s farmers can expect corn to reach far higher than the knee come Independence Day. According to the Iowa Corn Growers Association, under good conditions, Iowa corn plants typically reach a height of 8 feet by midsummer.


In some areas across the U.S., farmers have turned to Rodgers and Hammerstein’s musical, Oklahoma!, for a new adage. Since knee-high is no longer as relevant, corn should be “as high as an elephant’s eye” by the Fourth of July.


The saying comes from the Oklahoma! song “Oh, What a Beautiful Morning,” in which the main characters marvel at the height of the corn singing, “There’s a bright golden haze on the meadow / The corn is as high as an elephant’s eye, / An’ it looks like it’s climbin’ clear up to the sky.” 


“Knee-high by the Fourth of July” may be in the past, but thanks to its catchy nature and once practical use in predicting yields, the phrase has transformed into a tradition for many. For others, the new Oklahoma! inspired tradition has also taken hold. Regardless, the Fourth remains a milestone in the growing season and a time when many farmers look to their crops for indication of a plentiful harvest come fall.


“Either way you look at it, farmers ultimately measure their success after harvest,” said Paula Halabicki, BASF Technical Marketing Manager. “To that end, it is critical for farmers to maintain healthy crops throughout the growing season.”


With increased disease control, growth efficiency and stress tolerance, corn has begun to reach new heights and new yields. Hopefully, this Independence Day – traditions aside – farmers across the country turned to their crops to see that everything really was going their way.