In the regions where the phrase " knee high by the 4th of July" is used, the meaning is, that if it is not that high by that time, itis going to be a failure crop.
A few years ago, the American Heart Association ran advertisements that told people to use “hand only CPR” if someone loses consciousness. They did not bother to point out that it was important to check if there is a pulse of it the patient i breathing, when it was pointed out to the American Heart Association that to do any CPR on a person with a heart beat could be very bad, their answer was that they were just trying to raise awareness and no one would do CPR without getting proper training. It is a good thing (I know, it is fiction) that Luann was able to stop the jock from killing Mrs. Horner with CPR.
We flew to Arizona from a strip in our back yard, someone asked me why I flew. I told them it takes two days to drive. He then asked my wife how many days it took to fly, she told him two days. In my defense, we did not leave until after the frost melted off the wing at noon and arrive in Yuma by noon the next day.
A few years ago, a neighbor told my wife that I taught him to burp the alphabet 60 years ago. In my defense, I had learned from a Great uncle who had throat cancer and had his larynx removed. That was how he talked. Last year I was treated for throat cancer, they did not have to remove my larynx though. So it turns out it was a skill that I did not need to learn.
In the regions where the phrase " knee high by the 4th of July" is used, the meaning is, that if it is not that high by that time, itis going to be a failure crop.