Understanding how plants can talk provides us with an opportunity to eavesdrop into their conversation and explore how this exchange of information is affecting plant health. I will illustrate using research examples, how quickly crop plants are able to detect and respond to the presence of neighboring weeds. I will attempt to prove the crop plants such as corn and soybeans growing in the presence of weeds are in a state of constant communication. This communication results in molecular, physiological and morphological changes that help explain crop yield loss caused by weeds. These results also provide a scientific basis for the importance of early season week control.