U.S. Corn Crop Way Past ‘Knee High by the Fourth of July’ Benchmark

“Knee-high by the Fourth of July” is an adage most growers know. According to BASF, knee-high corn in early July was at one time believed to be an indicator of high yields.

These days, thanks to advancements in agriculture, farmers can expect corn to be a lot taller by the summer benchmark date. According to Iowa Corn, corn plants grown under good conditions usually reach a height of about 8 feet by midsummer in Iowa.

As June came to a close, 8% of the crop in the country’s top corn-growing states reached the silking stage, USDA reported. Since corn plants are at maximum or near-maximum height once silking occurs, according to Ohio State University Extension, that means almost a tenth of the nation’s crop is roughly as tall as it’s going to get. So much for knee-high — this corn is already towering.

Here’s a look at how corn silking progress is going across the country, highlighting four states with a quarter or more of the crop at the silking stage.

Kentucky

In Kentucky, corn silking progress reached 25% the week ending June 29. It was a big jump from the week before, when just 9% of the crop had reached the silking stage.

The five year average for corn silking in the Bluegrass State is 18%.

Tennessee

Just to the south, corn silking progress in Tennessee reached 45% the week ending June 29, an increase of 16 percentage points from the previous week.

With that, Tennessee is well ahead of the five-year average of 34%.

North Carolina

USDA said 67% of North Carolina’s corn crop had reached the silking stage, up almost 20 points from the week prior, when progress had reached 48%.

North Carolina’s corn silking progress is the furthest ahead of schedule of all 18 top corn-growing states. The five-year average for corn silking at this point in the season in North Carolina is only 51%.

Texas

Texas has the highest percentage of its corn crop at the silking stage of all top states — 72% of the Lonestar State’s crop had reached the silking stage by June 29, an increase of 5 percentage points from the week prior.

The state’s five-year average for corn silking progress is 68%.

Other States

Ten other states reported corn at the silking stage in the latest report. In Illinois, Iowa, Kansas, Missouri, Nebraska, Ohio, and South Dakota, a greater percentage of the crop is at the silking stage than average. In Minnesota and North Dakota, corn silking progress is on track with average. 

The only state behind average is Indiana.

The crops in four states — Colorado, Michigan, Pennsylvania, and Wisconsin — had not reached the silking stage as of June 29. That tracks with the average pace for those states.