knee-high by the 4th of July

*knee-high by the 4th of July

Fig. grown as tall as it should. (Corn seedlings are proverbially supposed to be as high as someone's knee by July 4th.) (*Typically: be ~; become ~; grow ~.) What with this drought, I don't think the crop will be knee-high by the 4th of July. It's gonna be a good year. Knee-high by the 4th of July.
See also: 4th, by, July, of
References in periodicals archive ?
We usually say it should be knee-high by the 4th of July but it's already up to my shoulders.