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